Marianne Huebner | Michigan State University (original) (raw)

Papers by Marianne Huebner

Research paper thumbnail of Assessment of coronary artery disease risk in 5463 patients undergoing cardiac surgery: When is preoperative coronary angiography necessary?

The Journal of Thoracic and Cardiovascular Surgery, 2013

Objectives: We sought to critically analyze the routine use of conventional coronary angiography ... more Objectives: We sought to critically analyze the routine use of conventional coronary angiography (CCA) before noncoronary cardiac surgery and to assess clinical prediction models that might allow more selective use of CCA in this setting.

Research paper thumbnail of The impact of competitive flow on distal coronary flow and on graft flow during coronary artery bypass surgery

Interactive cardiovascular and thoracic surgery, 2011

To determine the impact of left anterior descending-competitive flow (LAD-CF) on distal coronary ... more To determine the impact of left anterior descending-competitive flow (LAD-CF) on distal coronary flow (LAD-DF) and on left internal mammary artery-graft flow (LIMA-GF), we performed a quantitative blood-flow analysis in a swine model of a LIMA-to-LAD coronary artery bypass graft (CABG). In six swine, a LIMA-to-LAD CABG was performed. LAD blood-flow was measured bilaterally to the LIMA-to-LAD anastomosis, in the LIMA and in the pulmonary artery (cardiac output, CO) along with the LIMA pulsatility index (LIMA-PI) and the left ventricular pressure (LVP). PreCABG measurements were followed by postCABG measurements at five levels of LAD-CF: 100%, 75%, 50%, 25% and 0% after gradually snaring down a snare placed proximally of the LAD-CF flow-probe. PreCABG CO and LVP remained unchanged postCABG. LAD-DF was reduced significantly postCABG (-33%, P<0.0001). Reduction of the LAD-CF (at 75%, 50%, 25% and 0%) resulted in significant increase of LIMA-GF (+38%, +63%, +113%, +225%, P<0.036 at...

Research paper thumbnail of SNP interaction detection with Random Forests in high-dimensional genetic data

BMC bioinformatics, 2012

Background: Identifying variants associated with complex human traits in high-dimensional data is... more Background: Identifying variants associated with complex human traits in high-dimensional data is a central goal of genome-wide association studies. However, complicated etiologies such as gene-gene interactions are ignored by the univariate analysis usually applied in these studies. Random Forests (RF) are a popular data-mining technique that can accommodate a large number of predictor variables and allow for complex models with interactions. RF analysis produces measures of variable importance that can be used to rank the predictor variables. Thus, single nucleotide polymorphism (SNP) analysis using RFs is gaining popularity as a potential filter approach that considers interactions in high-dimensional data. However, the impact of data dimensionality on the power of RF to identify interactions has not been thoroughly explored. We investigate the ability of rankings from variable importance measures to detect gene-gene interaction effects and their potential effectiveness as filters compared to p-values from univariate logistic regression, particularly as the data becomes increasingly high-dimensional. Results: RF effectively identifies interactions in low dimensional data. As the total number of predictor variables increases, probability of detection declines more rapidly for interacting SNPs than for non-interacting SNPs, indicating that in high-dimensional data the RF variable importance measures are capturing marginal effects rather than capturing the effects of interactions. Conclusions: While RF remains a promising data-mining technique that extends univariate methods to condition on multiple variables simultaneously, RF variable importance measures fail to detect interaction effects in highdimensional data in the absence of a strong marginal component, and therefore may not be useful as a filter technique that allows for interaction effects in genome-wide data.

Research paper thumbnail of Temporomandibular custom hemijoint replacement prosthesis: prospective clinical and kinematic study

Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons, 2012

Purpose: Evaluate the clinical and functional outcome of a custom temporomandibular hemi-joint fo... more Purpose: Evaluate the clinical and functional outcome of a custom temporomandibular hemi-joint fossa/eminence implant prosthesis.

Research paper thumbnail of Outcomes following surgery without radiotherapy for rectal cancer

The British journal of surgery, 2012

Background:This study determined survival and recurrence rates following curative resection of re... more Background:This study determined survival and recurrence rates following curative resection of rectal cancer without radiotherapy.This study determined survival and recurrence rates following curative resection of rectal cancer without radiotherapy.Methods:This was a retrospective review of the Mayo Clinic database of patients with rectal cancer treated with curative intent using surgery alone from 1990 to 2006. Patients who received neoadjuvant chemotherapy or radiation therapy and those who had any postoperative radiotherapy were excluded. Details were collected from the database and patient records using a protocol approved by the institutional review board.This was a retrospective review of the Mayo Clinic database of patients with rectal cancer treated with curative intent using surgery alone from 1990 to 2006. Patients who received neoadjuvant chemotherapy or radiation therapy and those who had any postoperative radiotherapy were excluded. Details were collected from the database and patient records using a protocol approved by the institutional review board.Results:Some 655 consecutive patients with rectal cancer treated with curative intent using surgery alone were identified; 397 had stage I disease, 125 stage II and 133 stage III. Four hundred and nine patients underwent anterior resection (AR) and 246 abdominoperineal resection (APR). Median follow-up was 62 months. The 5-year rate of local recurrence was 4·3 per cent, disease-free survival 90·0 per cent and cancer-specific survival 91·5 per cent. Stage-specific and all-stage disease-free survival did not differ significantly between AR and APR. The 5-year cumulative local recurrence rate was lower following AR than APR (3·6 versus 5·5 per cent; P = 0·321). There were only two patients with positive margins and type of operation was not significant on multivariable analysis.Some 655 consecutive patients with rectal cancer treated with curative intent using surgery alone were identified; 397 had stage I disease, 125 stage II and 133 stage III. Four hundred and nine patients underwent anterior resection (AR) and 246 abdominoperineal resection (APR). Median follow-up was 62 months. The 5-year rate of local recurrence was 4·3 per cent, disease-free survival 90·0 per cent and cancer-specific survival 91·5 per cent. Stage-specific and all-stage disease-free survival did not differ significantly between AR and APR. The 5-year cumulative local recurrence rate was lower following AR than APR (3·6 versus 5·5 per cent; P = 0·321). There were only two patients with positive margins and type of operation was not significant on multivariable analysis.Conclusion:Well-performed, standardized APRs have similar local recurrence to AR. Radiation therapy may not confer much additional benefit. Copyright © 2011 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.Well-performed, standardized APRs have similar local recurrence to AR. Radiation therapy may not confer much additional benefit. Copyright © 2011 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.

Research paper thumbnail of Young-onset rectal cancer: presentation, pattern of care and long-term oncologic outcomes compared to a matched older-onset cohort

Annals of surgical oncology, 2011

Background Recent population-based studies have highlighted a disproportionate increase in the in... more Background Recent population-based studies have highlighted a disproportionate increase in the incidence of rectal cancer among adults younger than aged 50 years. To determine whether different intervention and surveillance strategies might be needed for younger patients, the patterns of care and oncologic outcomes among adults younger than aged 50 years with rectal cancer were investigated. Methods A cohort of 333 young (<50 years) patients with sporadic rectal cancer was compared to a contemporaneous cohort of 675 older (>65 years) patients for differences in disease pattern, treatments received, and long-term disease-free survival (DFS). Results Patient and tumor characteristics did not differ between groups except for an increased presence of signet-ring and mucinous histology in young patients. Younger patients presented with more advanced-stage disease (stages III and IV: 59.4% vs. 46.4%; p = 0.016). More young patients received sphincter-preservation procedures (63.4 vs. 55.4%; p = 0.016), radiation (61.6 vs. 42.1%; p < 0.001), and chemotherapy (67.3 vs. 47.6%; p < 0.001). Fewer young patients were free from recurrent disease at the last follow-up (72.1 vs. 82.5%; p < 0.001). The stage-specific 5-year DFS did not differ between the young and older cohorts. Only stage and the need for chemotherapy independently predicted poor DFS. Conclusions Young patients present at a later stage and a greater proportion develop distant disease recurrence over time. However, their stage-specific oncologic outcomes appear similar to those in older-onset patients. To have the greatest impact on long-term oncologic outcomes in patients with young-onset rectal cancer, future interventions should target strategies to diagnosis rectal cancer earlier, and once diagnosed, closer surveillance for recurrence may be warranted.

Research paper thumbnail of Estimating underreported N2 disease in rectal cancer patients with low lymph node counts

Journal of surgical oncology, 2012

BackgroundThe variability in the number of lymph nodes examined needs to be taken into account fo... more BackgroundThe variability in the number of lymph nodes examined needs to be taken into account for adequate staging. The definition of nodal staging was refined by quantifying the likelihood of N2 disease when the patient had fewer than four positive LN.The variability in the number of lymph nodes examined needs to be taken into account for adequate staging. The definition of nodal staging was refined by quantifying the likelihood of N2 disease when the patient had fewer than four positive LN.MethodsIn a retrospective study a total of 548 patients with node positive rectal cancer and curative surgery between 1990 and 2006 were identified. The misclassification of pN staging was estimated with a Bayesian computation. The prognostic value of the calculated probability, lymph node ratio (LNR), and nodal stage was assessed with Cox proportional hazard regression.In a retrospective study a total of 548 patients with node positive rectal cancer and curative surgery between 1990 and 2006 were identified. The misclassification of pN staging was estimated with a Bayesian computation. The prognostic value of the calculated probability, lymph node ratio (LNR), and nodal stage was assessed with Cox proportional hazard regression.ResultsA probability of understaging of 40% or more indicated worse prognosis of cancer-specific survival (CSS) with hazard ratio 2.6 (95%CI: 1.8–3.9, P < 0.001). The concordance index of a multivariate model with probability of N2 disease as a prognostic factor for survival was 0.68 for all patients and 0.75 for patients with less than 10 lymph nodes examined.A probability of understaging of 40% or more indicated worse prognosis of cancer-specific survival (CSS) with hazard ratio 2.6 (95%CI: 1.8–3.9, P < 0.001). The concordance index of a multivariate model with probability of N2 disease as a prognostic factor for survival was 0.68 for all patients and 0.75 for patients with less than 10 lymph nodes examined.ConclusionUtilizing estimated probabilities of N2 disease improves our ability to predict survival, in particular in patients with low LN count. These probabilities allow for a simple rule in patient counseling and clinical decision making. J. Surg. Oncol. 2012; 106:248–253. © 2011 Wiley Periodicals, Inc.Utilizing estimated probabilities of N2 disease improves our ability to predict survival, in particular in patients with low LN count. These probabilities allow for a simple rule in patient counseling and clinical decision making. J. Surg. Oncol. 2012; 106:248–253. © 2011 Wiley Periodicals, Inc.

Research paper thumbnail of National practice patterns in preoperative and postoperative antibiotic prophylaxis in breast procedures requiring drains: survey of the American Society of Breast Surgeons

Annals of surgical oncology, 2012

Background To assess national practice patterns regarding use of perioperative antibiotics by sur... more Background To assess national practice patterns regarding use of perioperative antibiotics by surgeons performing breast operations requiring drainage tubes. Methods The members of the American Society of Breast Surgeons (ASBrS) were surveyed regarding use of perioperative antibiotics for breast operations requiring drains, with or without immediate tissue expander or implant reconstruction. Results Of 2,857 ASBrS members contacted, 917 (32 %) responded; all self-identified as surgeons. Of 905 evaluable respondents, most described themselves as general surgeons (46 %) or breast surgeons (46 %). For cases in which drains are anticipated, most respondents (86 %) reported routine use of preoperative prophylactic antibiotics, with 99 % selecting cephalosporins. Use of antibiotic >24 h postoperatively varied by whether or not reconstruction was performed. In nonreconstruction cases, the majority (76 %) reported “never/almost never” prescribing antibiotics beyond the 24-h postoperative period, but 16 % reported “always/almost always.” In reconstruction cases, the majority (58 %) reported routine antibiotic use beyond 24 h, and the primary driver of the decision to use antibiotics was reported to be the plastic surgeon (83 %). Among those reporting use at >24 h, the duration recommended for nonreconstruction cases was “up to 1 week” in 38 % and “until drains removed” in 39 %; this was similar for reconstruction cases. Conclusions Cephalosporins are utilized uniformly as preoperative antibiotic prophylaxis in breast operations requiring drains. However, use of postoperative antibiotic prophylaxis is strongly dependent on the presence of immediate breast reconstruction. Consensus is lacking on the role of postoperative antibiotic prophylaxis in breast operations utilizing drains.

Research paper thumbnail of Mastery learning simulation-based curriculum for laparoscopic TEP inguinal hernia repair

Journal of surgical education

The laparoscopic totally extraperitoneal (TEP) inguinal herniorrhaphy requires 250 repairs to mas... more The laparoscopic totally extraperitoneal (TEP) inguinal herniorrhaphy requires 250 repairs to master. Simulation training could potentially accelerate this process. We describe the development, evaluation and implementation of a TEP mastery learning curriculum.

Research paper thumbnail of Prospective, observational validation of a multivariate small-bowel obstruction model to predict the need for operative intervention

Journal of the American College of Surgeons, 2011

We published previously a model predictive of the need for exploration in small-bowel obstruction... more We published previously a model predictive of the need for exploration in small-bowel obstruction. We aimed to validate and refine the model, hypothesizing that the model would be predictive, would prevent delayed management of strangulation, and would be successfully improved. STUDY DESIGN: Data from 100 consecutive patients with small-bowel obstruction and concurrent CT were collected prospectively. New features evaluated included obstipation and the absence of colonic gas on CT.

Research paper thumbnail of The off-pump implantation of an apicoaortic valved graft is safe and has no negative impact on coronary flow and hemodynamics

Innovations (Philadelphia, Pa.), 2011

: To determine the hemodynamic effect of an off-pump apicoaortic valved graft (AAVG) implantation... more : To determine the hemodynamic effect of an off-pump apicoaortic valved graft (AAVG) implantation, we performed a quantitative coronary flow analysis in a swine model of severe aortic stenosis. : In 10 swine, cardiac output, coronary flow, right common carotid artery flow, and internal mammary artery flow were measured along with left and right ventricular pressures and aortic and pulmonary artery pressures. A novel AAVG was implanted off-pump on the left ventricular (LV) apex using a specially designed implantation tool and anastomosed to the descending thoracic aorta. Aortic flow was measured proximally and distally of the AAVG-to-descending thoracic aorta anastomosis. After AAVG implantation, epicardial echo confirmed occlusion of the LV outflow tract by a valvuloplasty balloon. Baseline simultaneous measurements of all parameters were repeated after AAVG implantation and intravenous Dobutamine administration. : The AAVG was implanted without any blood loss. After AAVG implantation and LV outflow tract occlusion, the aortic flow proximal to the AAVG-to-descending thoracic aorta anastomosis changed from antegrade (1508 ± 435 mL/min) to retrograde (-529 ± 241 mL/min, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001). All other measured parameters remained unchanged compared with baseline. After intravenous Dobutamine administration, LV pressure increased from 88 ± 20 to 184 ± 36 mm Hg (+209%, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.0001) and coronary flow increased from 75 ± 34 to 193 ± 90 mL/min (+257%, P = 0.001). : The off-pump implantation of an AAVG is bloodless, safe, reproducible and has no negative impact on coronary flow and hemodynamics. In addition, to the best of our knowledge, this is the first study where blood flow in all coronary arteries was measured simultaneously during an AAVG implantation.

Research paper thumbnail of Randomized study of natural orifice transluminal endoscopic surgery and endoscopy shows similar hemodynamic impact in a porcine model

Surgical endoscopy, 2011

Background A previous porcine study showed a significant difference in heart rate and diastolic b... more Background A previous porcine study showed a significant difference in heart rate and diastolic blood pressure (DBP) between natural orifice transluminal endoscopic surgery (NOTES) and laparoscopy. This study evaluated the hemodynamics during endoscopy, laparoscopy, and transluminal access. Methods For this study, 37 female swine were randomized and invasively monitored in terms of blood and abdominal pressure, heart rate, and arterial blood gas (ABG) during 90-min procedures. Group 1 (n = 11) underwent NOTES peritoneoscopy; group 2 (n = 14) underwent 45-min diagnostic endoscopy, a 10-min washout period, and 35-min laparoscopy with mesh placement; and group 3 (n = 12) NOTES had transgastric mesh placement. The groups were compared using a mixed model and a Spearman trend test. This study was approved by Institutional Animal Care and Use Committee (IACUC). Results No difference in the systolic blood pressure (SBP) was noted. During the initial 30 min, DBP increased significantly from baseline in groups 1 (p < 0.001) and 2 (p = 0.01), but not in group 3 (p = 0.08). The mean DBP did not differ between the groups. During laparoscopy, the average end-tidal carbon dioxide (CO2) level was 6.6 mmHg higher in group 2 than in group 1 (p = 0.01). The heart rate and ABG values did not differ between the groups (p ≥ 0.10). Conclusion Heart rate and DBP were similar for NOTES and endoscopy. The differences seen in a previous trial comparing NOTES and laparoscopy were not duplicated. The initial DBP increased for the endoscopy and diagnostic NOTES animals. Differences in end-tidal CO2 were encountered again during the shortened laparoscopy segment.

Research paper thumbnail of Assessing the invasiveness of NOTES perforated viscus repair: a comparative study of NOTES and laparoscopy

Surgical endoscopy, 2012

Background Natural orifice transluminal endoscopic surgery (NOTES) repair of perforated peptic ul... more Background Natural orifice transluminal endoscopic surgery (NOTES) repair of perforated peptic ulcers may decrease surgical invasiveness and improve patient outcomes. Methods Full thickness gastrotomy was created laparoscopically in swine followed by soilage time. Repair proceeded with a laparoscopic (n = 14) or the NOTES (n = 14) approach. For NOTES repair, the omentum was endoscopically pulled into the gastric lumen and clipped. Intraoperative and postoperative parameters were recorded, including arterial blood gas (ABG) analysis and serum samples for white blood cell (WBC), TNF-α, IL-1, and IL-6 analysis. Results Twenty-four of 28 animals thrived to study completion. NOTES repair could not be accomplished in one animal. At necropsy, all repairs were intact. Blood pressure was equivalent between groups. Pulse examined during the last 30 min of each procedure revealed a slightly higher mean pulse in the animals undergoing NOTES procedures (NOTES, 102 ± 28; laparoscopy, 83 ± 24). ABG obtained at the conclusion of the procedure revealed a pH of 7.47 in NOTES animals and 7.43 in the laparoscopy animals (p = 0.06), a change from baseline in both groups. The final pCO2 was lower in the NOTES group (NOTES, 40.62; laparoscopy, 47.49, p = 0.03). WBC counts were comparable on postoperative day (POD) 1 (NOTES, 21.1; laparoscopy, 19.0; p = 0.49). Mean TNF-α serum levels were equivalent at all time points between groups; however, TNF-α varied significantly from baseline to POD 7 (p = 0.002). Conclusion NOTES omental repair appears comparable to that of laparoscopy. The lower arterial pCO2 at the conclusion of the NOTES procedure may be advantageous in critically ill patients.

Research paper thumbnail of The impact of competitive flow on distal coronary flow and on graft flow during coronary artery bypass surgery

Interactive cardiovascular and thoracic surgery, 2011

Research paper thumbnail of Quality of life after early mitral valve repair using conventional and robotic approaches

The Annals of thoracic surgery, 2012

Background. Early mitral valve (MV) repair of degenerative mitral regurgitation is associated wit... more Background. Early mitral valve (MV) repair of degenerative mitral regurgitation is associated with superior clinical outcomes compared with prosthetic replacement and restores normal life expectancy, even in those without symptoms. Although current guidelines recommend prompt referral for effective MV repair in those with severe mitral regurgitation, some are reluctant to pursue early correction due to the perception that short-term quality of life (QOL) may be adversely affected by the operation.

Research paper thumbnail of Handing over patient care: is it just the old broken telephone game

Journal of surgical education

BACKGROUND: Handing over patient care remains a poorly understood process and remains a leading c... more BACKGROUND: Handing over patient care remains a poorly understood process and remains a leading cause of medical error. We sought to examine how hand off delivery methods affect hand off quality and whether improvement would occur over time without formal training. DESIGN: Three simulated-patient hand offs were developed; each with a distinct delivery method: in-person (IP), video-based (VB), and screen-based (SB). Participants were evaluated up to 4 times, each 6 months apart. During evaluations, residents received the 3 hand offs, answered a sleep and preference questionnaire, and proceeded to hand off the same 3 patients. Sessions were video-reviewed and hand offs scored for quality measures: word accuracy, errors of omission or commission, and appropriateness of clinical judgment. Quality measures among delivery methods and changes over time were compared. RESULTS: Sixty-eight General Surgery residents (postgraduate year [PGY] 1-2) participated in at least 2 testing sessions, with 13 participating in 4. The IP method was superior to VB and SB for most hand off quality measures (each p Ͻ 0.001). With repeated testing, hand off quality measures improved (p Ͻ 0.001). However, patient hand offs continued to remain non-optimal, with appropriate judgment present in only 47%-77% of the hand offs. Sleep hours (mean 5 Ϯ 2) were not found to be associated with hand off quality measures (p Ͼ 0.05). Most trainees preferred the IP method (73% vs 5% VB, 15% SB, 7% other; p Ͻ 0.001).

Research paper thumbnail of Pulmonary and peritoneal inflammatory findings in transgastric NOTES compared with laparoscopy: pooled analysis from randomized porcine survival studies

Gastrointestinal endoscopy, 2011

Laparoscopy, which is a minimally invasive surgery, is associated with decreased peritoneal adhes... more Laparoscopy, which is a minimally invasive surgery, is associated with decreased peritoneal adhesions and inflammatory response compared with laparotomy. To evaluate whether natural orifice transluminal endoscopic surgery (NOTES) leads to an attenuated peritoneal response compared with laparoscopy. Pooled histologic analysis from 2 randomized porcine trials. Laboratory. Histologic analysis of swine undergoing diagnostic laparoscopy, diagnostic NOTES peritoneoscopy, NOTES with transgastric mesh placement, or diagnostic endoscopy (no gastrotomy) followed by laparoscopic mesh placement. The presence and grade of inflammation in necropsy specimens of lung, liver, and spleen as reviewed by a blinded veterinary pathologist. Four NOTES mesh animals exhibited mesh infections at necropsy. Tissue from 48 swine were available for analysis. Pulmonary inflammation, liver fibrosis, and spleen capsulitis were the primary findings. No difference was seen in the incidence of each finding among groups. The severity of the pulmonary inflammation in the laparoscopy group was significantly higher than in the NOTES groups. The NOTES mesh group exhibited significantly more severe liver fibrosis and spleen capsulitis. There was no difference between clinical behavior, serum white blood cell count, or peritoneal white blood cell count among groups in either study. Intra-abdominal pressures during NOTES were lower than during laparoscopy. Pooled analysis of 2 separate studies. More severe pulmonary inflammation was found in animals undergoing longer laparoscopic procedures with higher intra-abdominal pressures. Intraperitoneal inflammation was most significant with transgastric mesh placement, likely caused by infections.

Research paper thumbnail of Case-matched series of enhanced versus standard recovery pathway in minimally invasive colorectal surgery

The British journal of surgery, 2012

Background:Accelerated recovery pathways may reduce length of hospital stay after surgery but the... more Background:Accelerated recovery pathways may reduce length of hospital stay after surgery but there are few data on minimally invasive colorectal operations.Accelerated recovery pathways may reduce length of hospital stay after surgery but there are few data on minimally invasive colorectal operations.Methods:An enhanced recovery pathway (ERP) was instituted, including preoperative analgesia, limited intravenous fluids and opiates, and early feeding. Intrathecal analgesia was administered as needed, but epidural analgesia was not used. The first 66 patients subjected to the ERP were case-matched by surgeon, procedure and age (within 5 years) with patients treated previously in a fast-track pathway (FTP). Short-term and postoperative outcomes to 30 days were compared.An enhanced recovery pathway (ERP) was instituted, including preoperative analgesia, limited intravenous fluids and opiates, and early feeding. Intrathecal analgesia was administered as needed, but epidural analgesia was not used. The first 66 patients subjected to the ERP were case-matched by surgeon, procedure and age (within 5 years) with patients treated previously in a fast-track pathway (FTP). Short-term and postoperative outcomes to 30 days were compared.Results:Hospital stay was shorter with the ERP than the FTP: median (interquartile range, i.q.r.) 3 (2–3) versus 3 (3–5) days (P < 0·001). A 2-day hospital stay was achieved in 44 and 8 per cent of patients respectively (P < 0·001). Patients in the ERP had a shorter time to recovery of bowel function: median (i.q.r.) 1 (1–2) versus 2 (2–3) days (P < 0·001). Thirty-day complication rates were similar (32 per cent ERP, 27 per cent FTP; P = 0·570). Readmissions within 30 days were more common with ERP, but the difference was not statistically significant (10 versus 5 patients; P = 0·170). Total hospital stay for those readmitted was shorter in the ERP group (18 versus 23 days).Hospital stay was shorter with the ERP than the FTP: median (interquartile range, i.q.r.) 3 (2–3) versus 3 (3–5) days (P < 0·001). A 2-day hospital stay was achieved in 44 and 8 per cent of patients respectively (P < 0·001). Patients in the ERP had a shorter time to recovery of bowel function: median (i.q.r.) 1 (1–2) versus 2 (2–3) days (P < 0·001). Thirty-day complication rates were similar (32 per cent ERP, 27 per cent FTP; P = 0·570). Readmissions within 30 days were more common with ERP, but the difference was not statistically significant (10 versus 5 patients; P = 0·170). Total hospital stay for those readmitted was shorter in the ERP group (18 versus 23 days).Conclusion:ERP decreased the length of hospital stay after minimally invasive colorectal surgery. Copyright © 2011 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.ERP decreased the length of hospital stay after minimally invasive colorectal surgery. Copyright © 2011 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.

Research paper thumbnail of Mayo Clinic consensus recommendations for the depth of excision in primary cutaneous melanoma

Mayo Clinic proceedings. Mayo Clinic, 2011

Research paper thumbnail of Number of lymph nodes evaluated: prognostic value in pancreatic adenocarcinoma

Journal of gastrointestinal surgery : official journal of the Society for Surgery of the Alimentary Tract, 2012

Introduction The impact of the number of lymph node (LN) evaluated pathologically on accurate sta... more Introduction The impact of the number of lymph node (LN) evaluated pathologically on accurate staging is unknown. Our primary aim was to determine a minimum number of evaluated LN needed to provide accurate staging of pancreatic cancer. Methods Four hundred ninety-nine patients underwent a curative pancreatectomy for pancreatic adenocarcinoma cancer from 1981–2007. The probability of understaging a patient as N0 was estimated based on the number of LN evaluated. The prognostic value of LN ratio (LNR) was assessed. Results Survival for node-negative (pN0) patients with <11 LN examined was worse than for pN0 patients with ≥11 LNs with a hazard ratio (95 % CI) of 1.33 (1.1–1.7, p = 0.01) with 3-year survivals of 32 vs. 50%, respectively. Three-year survival for pN1 patients with <11 nodes evaluated was similar to pN1 patients with ≥11 nodes (25 vs. 30%). LNR ≥ 0.17 predicted worse survival with hazard ratio of 1.76 (1.3–2.4, p = 0.001) than LNR < 0.17; 3-year survivals were 37 vs. 19%. Conclusion Patients with “N0” disease with <11 LN evaluated pathologically have worse survival, suggesting that metastatic nodes were missed by evaluating too few nodes. For pN1 patients, LNR stratifies survival of patient cohorts more accurately. Adequate staging of pancreatic cancer requires pathologic evaluation of ≥11 LNs.

Research paper thumbnail of Assessment of coronary artery disease risk in 5463 patients undergoing cardiac surgery: When is preoperative coronary angiography necessary?

The Journal of Thoracic and Cardiovascular Surgery, 2013

Objectives: We sought to critically analyze the routine use of conventional coronary angiography ... more Objectives: We sought to critically analyze the routine use of conventional coronary angiography (CCA) before noncoronary cardiac surgery and to assess clinical prediction models that might allow more selective use of CCA in this setting.

Research paper thumbnail of The impact of competitive flow on distal coronary flow and on graft flow during coronary artery bypass surgery

Interactive cardiovascular and thoracic surgery, 2011

To determine the impact of left anterior descending-competitive flow (LAD-CF) on distal coronary ... more To determine the impact of left anterior descending-competitive flow (LAD-CF) on distal coronary flow (LAD-DF) and on left internal mammary artery-graft flow (LIMA-GF), we performed a quantitative blood-flow analysis in a swine model of a LIMA-to-LAD coronary artery bypass graft (CABG). In six swine, a LIMA-to-LAD CABG was performed. LAD blood-flow was measured bilaterally to the LIMA-to-LAD anastomosis, in the LIMA and in the pulmonary artery (cardiac output, CO) along with the LIMA pulsatility index (LIMA-PI) and the left ventricular pressure (LVP). PreCABG measurements were followed by postCABG measurements at five levels of LAD-CF: 100%, 75%, 50%, 25% and 0% after gradually snaring down a snare placed proximally of the LAD-CF flow-probe. PreCABG CO and LVP remained unchanged postCABG. LAD-DF was reduced significantly postCABG (-33%, P<0.0001). Reduction of the LAD-CF (at 75%, 50%, 25% and 0%) resulted in significant increase of LIMA-GF (+38%, +63%, +113%, +225%, P<0.036 at...

Research paper thumbnail of SNP interaction detection with Random Forests in high-dimensional genetic data

BMC bioinformatics, 2012

Background: Identifying variants associated with complex human traits in high-dimensional data is... more Background: Identifying variants associated with complex human traits in high-dimensional data is a central goal of genome-wide association studies. However, complicated etiologies such as gene-gene interactions are ignored by the univariate analysis usually applied in these studies. Random Forests (RF) are a popular data-mining technique that can accommodate a large number of predictor variables and allow for complex models with interactions. RF analysis produces measures of variable importance that can be used to rank the predictor variables. Thus, single nucleotide polymorphism (SNP) analysis using RFs is gaining popularity as a potential filter approach that considers interactions in high-dimensional data. However, the impact of data dimensionality on the power of RF to identify interactions has not been thoroughly explored. We investigate the ability of rankings from variable importance measures to detect gene-gene interaction effects and their potential effectiveness as filters compared to p-values from univariate logistic regression, particularly as the data becomes increasingly high-dimensional. Results: RF effectively identifies interactions in low dimensional data. As the total number of predictor variables increases, probability of detection declines more rapidly for interacting SNPs than for non-interacting SNPs, indicating that in high-dimensional data the RF variable importance measures are capturing marginal effects rather than capturing the effects of interactions. Conclusions: While RF remains a promising data-mining technique that extends univariate methods to condition on multiple variables simultaneously, RF variable importance measures fail to detect interaction effects in highdimensional data in the absence of a strong marginal component, and therefore may not be useful as a filter technique that allows for interaction effects in genome-wide data.

Research paper thumbnail of Temporomandibular custom hemijoint replacement prosthesis: prospective clinical and kinematic study

Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons, 2012

Purpose: Evaluate the clinical and functional outcome of a custom temporomandibular hemi-joint fo... more Purpose: Evaluate the clinical and functional outcome of a custom temporomandibular hemi-joint fossa/eminence implant prosthesis.

Research paper thumbnail of Outcomes following surgery without radiotherapy for rectal cancer

The British journal of surgery, 2012

Background:This study determined survival and recurrence rates following curative resection of re... more Background:This study determined survival and recurrence rates following curative resection of rectal cancer without radiotherapy.This study determined survival and recurrence rates following curative resection of rectal cancer without radiotherapy.Methods:This was a retrospective review of the Mayo Clinic database of patients with rectal cancer treated with curative intent using surgery alone from 1990 to 2006. Patients who received neoadjuvant chemotherapy or radiation therapy and those who had any postoperative radiotherapy were excluded. Details were collected from the database and patient records using a protocol approved by the institutional review board.This was a retrospective review of the Mayo Clinic database of patients with rectal cancer treated with curative intent using surgery alone from 1990 to 2006. Patients who received neoadjuvant chemotherapy or radiation therapy and those who had any postoperative radiotherapy were excluded. Details were collected from the database and patient records using a protocol approved by the institutional review board.Results:Some 655 consecutive patients with rectal cancer treated with curative intent using surgery alone were identified; 397 had stage I disease, 125 stage II and 133 stage III. Four hundred and nine patients underwent anterior resection (AR) and 246 abdominoperineal resection (APR). Median follow-up was 62 months. The 5-year rate of local recurrence was 4·3 per cent, disease-free survival 90·0 per cent and cancer-specific survival 91·5 per cent. Stage-specific and all-stage disease-free survival did not differ significantly between AR and APR. The 5-year cumulative local recurrence rate was lower following AR than APR (3·6 versus 5·5 per cent; P = 0·321). There were only two patients with positive margins and type of operation was not significant on multivariable analysis.Some 655 consecutive patients with rectal cancer treated with curative intent using surgery alone were identified; 397 had stage I disease, 125 stage II and 133 stage III. Four hundred and nine patients underwent anterior resection (AR) and 246 abdominoperineal resection (APR). Median follow-up was 62 months. The 5-year rate of local recurrence was 4·3 per cent, disease-free survival 90·0 per cent and cancer-specific survival 91·5 per cent. Stage-specific and all-stage disease-free survival did not differ significantly between AR and APR. The 5-year cumulative local recurrence rate was lower following AR than APR (3·6 versus 5·5 per cent; P = 0·321). There were only two patients with positive margins and type of operation was not significant on multivariable analysis.Conclusion:Well-performed, standardized APRs have similar local recurrence to AR. Radiation therapy may not confer much additional benefit. Copyright © 2011 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.Well-performed, standardized APRs have similar local recurrence to AR. Radiation therapy may not confer much additional benefit. Copyright © 2011 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.

Research paper thumbnail of Young-onset rectal cancer: presentation, pattern of care and long-term oncologic outcomes compared to a matched older-onset cohort

Annals of surgical oncology, 2011

Background Recent population-based studies have highlighted a disproportionate increase in the in... more Background Recent population-based studies have highlighted a disproportionate increase in the incidence of rectal cancer among adults younger than aged 50 years. To determine whether different intervention and surveillance strategies might be needed for younger patients, the patterns of care and oncologic outcomes among adults younger than aged 50 years with rectal cancer were investigated. Methods A cohort of 333 young (<50 years) patients with sporadic rectal cancer was compared to a contemporaneous cohort of 675 older (>65 years) patients for differences in disease pattern, treatments received, and long-term disease-free survival (DFS). Results Patient and tumor characteristics did not differ between groups except for an increased presence of signet-ring and mucinous histology in young patients. Younger patients presented with more advanced-stage disease (stages III and IV: 59.4% vs. 46.4%; p = 0.016). More young patients received sphincter-preservation procedures (63.4 vs. 55.4%; p = 0.016), radiation (61.6 vs. 42.1%; p < 0.001), and chemotherapy (67.3 vs. 47.6%; p < 0.001). Fewer young patients were free from recurrent disease at the last follow-up (72.1 vs. 82.5%; p < 0.001). The stage-specific 5-year DFS did not differ between the young and older cohorts. Only stage and the need for chemotherapy independently predicted poor DFS. Conclusions Young patients present at a later stage and a greater proportion develop distant disease recurrence over time. However, their stage-specific oncologic outcomes appear similar to those in older-onset patients. To have the greatest impact on long-term oncologic outcomes in patients with young-onset rectal cancer, future interventions should target strategies to diagnosis rectal cancer earlier, and once diagnosed, closer surveillance for recurrence may be warranted.

Research paper thumbnail of Estimating underreported N2 disease in rectal cancer patients with low lymph node counts

Journal of surgical oncology, 2012

BackgroundThe variability in the number of lymph nodes examined needs to be taken into account fo... more BackgroundThe variability in the number of lymph nodes examined needs to be taken into account for adequate staging. The definition of nodal staging was refined by quantifying the likelihood of N2 disease when the patient had fewer than four positive LN.The variability in the number of lymph nodes examined needs to be taken into account for adequate staging. The definition of nodal staging was refined by quantifying the likelihood of N2 disease when the patient had fewer than four positive LN.MethodsIn a retrospective study a total of 548 patients with node positive rectal cancer and curative surgery between 1990 and 2006 were identified. The misclassification of pN staging was estimated with a Bayesian computation. The prognostic value of the calculated probability, lymph node ratio (LNR), and nodal stage was assessed with Cox proportional hazard regression.In a retrospective study a total of 548 patients with node positive rectal cancer and curative surgery between 1990 and 2006 were identified. The misclassification of pN staging was estimated with a Bayesian computation. The prognostic value of the calculated probability, lymph node ratio (LNR), and nodal stage was assessed with Cox proportional hazard regression.ResultsA probability of understaging of 40% or more indicated worse prognosis of cancer-specific survival (CSS) with hazard ratio 2.6 (95%CI: 1.8–3.9, P < 0.001). The concordance index of a multivariate model with probability of N2 disease as a prognostic factor for survival was 0.68 for all patients and 0.75 for patients with less than 10 lymph nodes examined.A probability of understaging of 40% or more indicated worse prognosis of cancer-specific survival (CSS) with hazard ratio 2.6 (95%CI: 1.8–3.9, P < 0.001). The concordance index of a multivariate model with probability of N2 disease as a prognostic factor for survival was 0.68 for all patients and 0.75 for patients with less than 10 lymph nodes examined.ConclusionUtilizing estimated probabilities of N2 disease improves our ability to predict survival, in particular in patients with low LN count. These probabilities allow for a simple rule in patient counseling and clinical decision making. J. Surg. Oncol. 2012; 106:248–253. © 2011 Wiley Periodicals, Inc.Utilizing estimated probabilities of N2 disease improves our ability to predict survival, in particular in patients with low LN count. These probabilities allow for a simple rule in patient counseling and clinical decision making. J. Surg. Oncol. 2012; 106:248–253. © 2011 Wiley Periodicals, Inc.

Research paper thumbnail of National practice patterns in preoperative and postoperative antibiotic prophylaxis in breast procedures requiring drains: survey of the American Society of Breast Surgeons

Annals of surgical oncology, 2012

Background To assess national practice patterns regarding use of perioperative antibiotics by sur... more Background To assess national practice patterns regarding use of perioperative antibiotics by surgeons performing breast operations requiring drainage tubes. Methods The members of the American Society of Breast Surgeons (ASBrS) were surveyed regarding use of perioperative antibiotics for breast operations requiring drains, with or without immediate tissue expander or implant reconstruction. Results Of 2,857 ASBrS members contacted, 917 (32 %) responded; all self-identified as surgeons. Of 905 evaluable respondents, most described themselves as general surgeons (46 %) or breast surgeons (46 %). For cases in which drains are anticipated, most respondents (86 %) reported routine use of preoperative prophylactic antibiotics, with 99 % selecting cephalosporins. Use of antibiotic >24 h postoperatively varied by whether or not reconstruction was performed. In nonreconstruction cases, the majority (76 %) reported “never/almost never” prescribing antibiotics beyond the 24-h postoperative period, but 16 % reported “always/almost always.” In reconstruction cases, the majority (58 %) reported routine antibiotic use beyond 24 h, and the primary driver of the decision to use antibiotics was reported to be the plastic surgeon (83 %). Among those reporting use at >24 h, the duration recommended for nonreconstruction cases was “up to 1 week” in 38 % and “until drains removed” in 39 %; this was similar for reconstruction cases. Conclusions Cephalosporins are utilized uniformly as preoperative antibiotic prophylaxis in breast operations requiring drains. However, use of postoperative antibiotic prophylaxis is strongly dependent on the presence of immediate breast reconstruction. Consensus is lacking on the role of postoperative antibiotic prophylaxis in breast operations utilizing drains.

Research paper thumbnail of Mastery learning simulation-based curriculum for laparoscopic TEP inguinal hernia repair

Journal of surgical education

The laparoscopic totally extraperitoneal (TEP) inguinal herniorrhaphy requires 250 repairs to mas... more The laparoscopic totally extraperitoneal (TEP) inguinal herniorrhaphy requires 250 repairs to master. Simulation training could potentially accelerate this process. We describe the development, evaluation and implementation of a TEP mastery learning curriculum.

Research paper thumbnail of Prospective, observational validation of a multivariate small-bowel obstruction model to predict the need for operative intervention

Journal of the American College of Surgeons, 2011

We published previously a model predictive of the need for exploration in small-bowel obstruction... more We published previously a model predictive of the need for exploration in small-bowel obstruction. We aimed to validate and refine the model, hypothesizing that the model would be predictive, would prevent delayed management of strangulation, and would be successfully improved. STUDY DESIGN: Data from 100 consecutive patients with small-bowel obstruction and concurrent CT were collected prospectively. New features evaluated included obstipation and the absence of colonic gas on CT.

Research paper thumbnail of The off-pump implantation of an apicoaortic valved graft is safe and has no negative impact on coronary flow and hemodynamics

Innovations (Philadelphia, Pa.), 2011

: To determine the hemodynamic effect of an off-pump apicoaortic valved graft (AAVG) implantation... more : To determine the hemodynamic effect of an off-pump apicoaortic valved graft (AAVG) implantation, we performed a quantitative coronary flow analysis in a swine model of severe aortic stenosis. : In 10 swine, cardiac output, coronary flow, right common carotid artery flow, and internal mammary artery flow were measured along with left and right ventricular pressures and aortic and pulmonary artery pressures. A novel AAVG was implanted off-pump on the left ventricular (LV) apex using a specially designed implantation tool and anastomosed to the descending thoracic aorta. Aortic flow was measured proximally and distally of the AAVG-to-descending thoracic aorta anastomosis. After AAVG implantation, epicardial echo confirmed occlusion of the LV outflow tract by a valvuloplasty balloon. Baseline simultaneous measurements of all parameters were repeated after AAVG implantation and intravenous Dobutamine administration. : The AAVG was implanted without any blood loss. After AAVG implantation and LV outflow tract occlusion, the aortic flow proximal to the AAVG-to-descending thoracic aorta anastomosis changed from antegrade (1508 ± 435 mL/min) to retrograde (-529 ± 241 mL/min, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001). All other measured parameters remained unchanged compared with baseline. After intravenous Dobutamine administration, LV pressure increased from 88 ± 20 to 184 ± 36 mm Hg (+209%, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.0001) and coronary flow increased from 75 ± 34 to 193 ± 90 mL/min (+257%, P = 0.001). : The off-pump implantation of an AAVG is bloodless, safe, reproducible and has no negative impact on coronary flow and hemodynamics. In addition, to the best of our knowledge, this is the first study where blood flow in all coronary arteries was measured simultaneously during an AAVG implantation.

Research paper thumbnail of Randomized study of natural orifice transluminal endoscopic surgery and endoscopy shows similar hemodynamic impact in a porcine model

Surgical endoscopy, 2011

Background A previous porcine study showed a significant difference in heart rate and diastolic b... more Background A previous porcine study showed a significant difference in heart rate and diastolic blood pressure (DBP) between natural orifice transluminal endoscopic surgery (NOTES) and laparoscopy. This study evaluated the hemodynamics during endoscopy, laparoscopy, and transluminal access. Methods For this study, 37 female swine were randomized and invasively monitored in terms of blood and abdominal pressure, heart rate, and arterial blood gas (ABG) during 90-min procedures. Group 1 (n = 11) underwent NOTES peritoneoscopy; group 2 (n = 14) underwent 45-min diagnostic endoscopy, a 10-min washout period, and 35-min laparoscopy with mesh placement; and group 3 (n = 12) NOTES had transgastric mesh placement. The groups were compared using a mixed model and a Spearman trend test. This study was approved by Institutional Animal Care and Use Committee (IACUC). Results No difference in the systolic blood pressure (SBP) was noted. During the initial 30 min, DBP increased significantly from baseline in groups 1 (p < 0.001) and 2 (p = 0.01), but not in group 3 (p = 0.08). The mean DBP did not differ between the groups. During laparoscopy, the average end-tidal carbon dioxide (CO2) level was 6.6 mmHg higher in group 2 than in group 1 (p = 0.01). The heart rate and ABG values did not differ between the groups (p ≥ 0.10). Conclusion Heart rate and DBP were similar for NOTES and endoscopy. The differences seen in a previous trial comparing NOTES and laparoscopy were not duplicated. The initial DBP increased for the endoscopy and diagnostic NOTES animals. Differences in end-tidal CO2 were encountered again during the shortened laparoscopy segment.

Research paper thumbnail of Assessing the invasiveness of NOTES perforated viscus repair: a comparative study of NOTES and laparoscopy

Surgical endoscopy, 2012

Background Natural orifice transluminal endoscopic surgery (NOTES) repair of perforated peptic ul... more Background Natural orifice transluminal endoscopic surgery (NOTES) repair of perforated peptic ulcers may decrease surgical invasiveness and improve patient outcomes. Methods Full thickness gastrotomy was created laparoscopically in swine followed by soilage time. Repair proceeded with a laparoscopic (n = 14) or the NOTES (n = 14) approach. For NOTES repair, the omentum was endoscopically pulled into the gastric lumen and clipped. Intraoperative and postoperative parameters were recorded, including arterial blood gas (ABG) analysis and serum samples for white blood cell (WBC), TNF-α, IL-1, and IL-6 analysis. Results Twenty-four of 28 animals thrived to study completion. NOTES repair could not be accomplished in one animal. At necropsy, all repairs were intact. Blood pressure was equivalent between groups. Pulse examined during the last 30 min of each procedure revealed a slightly higher mean pulse in the animals undergoing NOTES procedures (NOTES, 102 ± 28; laparoscopy, 83 ± 24). ABG obtained at the conclusion of the procedure revealed a pH of 7.47 in NOTES animals and 7.43 in the laparoscopy animals (p = 0.06), a change from baseline in both groups. The final pCO2 was lower in the NOTES group (NOTES, 40.62; laparoscopy, 47.49, p = 0.03). WBC counts were comparable on postoperative day (POD) 1 (NOTES, 21.1; laparoscopy, 19.0; p = 0.49). Mean TNF-α serum levels were equivalent at all time points between groups; however, TNF-α varied significantly from baseline to POD 7 (p = 0.002). Conclusion NOTES omental repair appears comparable to that of laparoscopy. The lower arterial pCO2 at the conclusion of the NOTES procedure may be advantageous in critically ill patients.

Research paper thumbnail of The impact of competitive flow on distal coronary flow and on graft flow during coronary artery bypass surgery

Interactive cardiovascular and thoracic surgery, 2011

Research paper thumbnail of Quality of life after early mitral valve repair using conventional and robotic approaches

The Annals of thoracic surgery, 2012

Background. Early mitral valve (MV) repair of degenerative mitral regurgitation is associated wit... more Background. Early mitral valve (MV) repair of degenerative mitral regurgitation is associated with superior clinical outcomes compared with prosthetic replacement and restores normal life expectancy, even in those without symptoms. Although current guidelines recommend prompt referral for effective MV repair in those with severe mitral regurgitation, some are reluctant to pursue early correction due to the perception that short-term quality of life (QOL) may be adversely affected by the operation.

Research paper thumbnail of Handing over patient care: is it just the old broken telephone game

Journal of surgical education

BACKGROUND: Handing over patient care remains a poorly understood process and remains a leading c... more BACKGROUND: Handing over patient care remains a poorly understood process and remains a leading cause of medical error. We sought to examine how hand off delivery methods affect hand off quality and whether improvement would occur over time without formal training. DESIGN: Three simulated-patient hand offs were developed; each with a distinct delivery method: in-person (IP), video-based (VB), and screen-based (SB). Participants were evaluated up to 4 times, each 6 months apart. During evaluations, residents received the 3 hand offs, answered a sleep and preference questionnaire, and proceeded to hand off the same 3 patients. Sessions were video-reviewed and hand offs scored for quality measures: word accuracy, errors of omission or commission, and appropriateness of clinical judgment. Quality measures among delivery methods and changes over time were compared. RESULTS: Sixty-eight General Surgery residents (postgraduate year [PGY] 1-2) participated in at least 2 testing sessions, with 13 participating in 4. The IP method was superior to VB and SB for most hand off quality measures (each p Ͻ 0.001). With repeated testing, hand off quality measures improved (p Ͻ 0.001). However, patient hand offs continued to remain non-optimal, with appropriate judgment present in only 47%-77% of the hand offs. Sleep hours (mean 5 Ϯ 2) were not found to be associated with hand off quality measures (p Ͼ 0.05). Most trainees preferred the IP method (73% vs 5% VB, 15% SB, 7% other; p Ͻ 0.001).

Research paper thumbnail of Pulmonary and peritoneal inflammatory findings in transgastric NOTES compared with laparoscopy: pooled analysis from randomized porcine survival studies

Gastrointestinal endoscopy, 2011

Laparoscopy, which is a minimally invasive surgery, is associated with decreased peritoneal adhes... more Laparoscopy, which is a minimally invasive surgery, is associated with decreased peritoneal adhesions and inflammatory response compared with laparotomy. To evaluate whether natural orifice transluminal endoscopic surgery (NOTES) leads to an attenuated peritoneal response compared with laparoscopy. Pooled histologic analysis from 2 randomized porcine trials. Laboratory. Histologic analysis of swine undergoing diagnostic laparoscopy, diagnostic NOTES peritoneoscopy, NOTES with transgastric mesh placement, or diagnostic endoscopy (no gastrotomy) followed by laparoscopic mesh placement. The presence and grade of inflammation in necropsy specimens of lung, liver, and spleen as reviewed by a blinded veterinary pathologist. Four NOTES mesh animals exhibited mesh infections at necropsy. Tissue from 48 swine were available for analysis. Pulmonary inflammation, liver fibrosis, and spleen capsulitis were the primary findings. No difference was seen in the incidence of each finding among groups. The severity of the pulmonary inflammation in the laparoscopy group was significantly higher than in the NOTES groups. The NOTES mesh group exhibited significantly more severe liver fibrosis and spleen capsulitis. There was no difference between clinical behavior, serum white blood cell count, or peritoneal white blood cell count among groups in either study. Intra-abdominal pressures during NOTES were lower than during laparoscopy. Pooled analysis of 2 separate studies. More severe pulmonary inflammation was found in animals undergoing longer laparoscopic procedures with higher intra-abdominal pressures. Intraperitoneal inflammation was most significant with transgastric mesh placement, likely caused by infections.

Research paper thumbnail of Case-matched series of enhanced versus standard recovery pathway in minimally invasive colorectal surgery

The British journal of surgery, 2012

Background:Accelerated recovery pathways may reduce length of hospital stay after surgery but the... more Background:Accelerated recovery pathways may reduce length of hospital stay after surgery but there are few data on minimally invasive colorectal operations.Accelerated recovery pathways may reduce length of hospital stay after surgery but there are few data on minimally invasive colorectal operations.Methods:An enhanced recovery pathway (ERP) was instituted, including preoperative analgesia, limited intravenous fluids and opiates, and early feeding. Intrathecal analgesia was administered as needed, but epidural analgesia was not used. The first 66 patients subjected to the ERP were case-matched by surgeon, procedure and age (within 5 years) with patients treated previously in a fast-track pathway (FTP). Short-term and postoperative outcomes to 30 days were compared.An enhanced recovery pathway (ERP) was instituted, including preoperative analgesia, limited intravenous fluids and opiates, and early feeding. Intrathecal analgesia was administered as needed, but epidural analgesia was not used. The first 66 patients subjected to the ERP were case-matched by surgeon, procedure and age (within 5 years) with patients treated previously in a fast-track pathway (FTP). Short-term and postoperative outcomes to 30 days were compared.Results:Hospital stay was shorter with the ERP than the FTP: median (interquartile range, i.q.r.) 3 (2–3) versus 3 (3–5) days (P < 0·001). A 2-day hospital stay was achieved in 44 and 8 per cent of patients respectively (P < 0·001). Patients in the ERP had a shorter time to recovery of bowel function: median (i.q.r.) 1 (1–2) versus 2 (2–3) days (P < 0·001). Thirty-day complication rates were similar (32 per cent ERP, 27 per cent FTP; P = 0·570). Readmissions within 30 days were more common with ERP, but the difference was not statistically significant (10 versus 5 patients; P = 0·170). Total hospital stay for those readmitted was shorter in the ERP group (18 versus 23 days).Hospital stay was shorter with the ERP than the FTP: median (interquartile range, i.q.r.) 3 (2–3) versus 3 (3–5) days (P < 0·001). A 2-day hospital stay was achieved in 44 and 8 per cent of patients respectively (P < 0·001). Patients in the ERP had a shorter time to recovery of bowel function: median (i.q.r.) 1 (1–2) versus 2 (2–3) days (P < 0·001). Thirty-day complication rates were similar (32 per cent ERP, 27 per cent FTP; P = 0·570). Readmissions within 30 days were more common with ERP, but the difference was not statistically significant (10 versus 5 patients; P = 0·170). Total hospital stay for those readmitted was shorter in the ERP group (18 versus 23 days).Conclusion:ERP decreased the length of hospital stay after minimally invasive colorectal surgery. Copyright © 2011 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.ERP decreased the length of hospital stay after minimally invasive colorectal surgery. Copyright © 2011 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.

Research paper thumbnail of Mayo Clinic consensus recommendations for the depth of excision in primary cutaneous melanoma

Mayo Clinic proceedings. Mayo Clinic, 2011

Research paper thumbnail of Number of lymph nodes evaluated: prognostic value in pancreatic adenocarcinoma

Journal of gastrointestinal surgery : official journal of the Society for Surgery of the Alimentary Tract, 2012

Introduction The impact of the number of lymph node (LN) evaluated pathologically on accurate sta... more Introduction The impact of the number of lymph node (LN) evaluated pathologically on accurate staging is unknown. Our primary aim was to determine a minimum number of evaluated LN needed to provide accurate staging of pancreatic cancer. Methods Four hundred ninety-nine patients underwent a curative pancreatectomy for pancreatic adenocarcinoma cancer from 1981–2007. The probability of understaging a patient as N0 was estimated based on the number of LN evaluated. The prognostic value of LN ratio (LNR) was assessed. Results Survival for node-negative (pN0) patients with <11 LN examined was worse than for pN0 patients with ≥11 LNs with a hazard ratio (95 % CI) of 1.33 (1.1–1.7, p = 0.01) with 3-year survivals of 32 vs. 50%, respectively. Three-year survival for pN1 patients with <11 nodes evaluated was similar to pN1 patients with ≥11 nodes (25 vs. 30%). LNR ≥ 0.17 predicted worse survival with hazard ratio of 1.76 (1.3–2.4, p = 0.001) than LNR < 0.17; 3-year survivals were 37 vs. 19%. Conclusion Patients with “N0” disease with <11 LN evaluated pathologically have worse survival, suggesting that metastatic nodes were missed by evaluating too few nodes. For pN1 patients, LNR stratifies survival of patient cohorts more accurately. Adequate staging of pancreatic cancer requires pathologic evaluation of ≥11 LNs.