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Papers by Anna Cass

Research paper thumbnail of Changing indications and outcomes for open abdominal aortic aneurysm repair since the advent of endovascular repair

The American surgeon, 2009

The indications for open abdominal aortic aneurysm (AAA) repair have changed with the development... more The indications for open abdominal aortic aneurysm (AAA) repair have changed with the development of endovascular techniques. The purpose of this study is to clarify the indications and outcomes for open repair since endovascular aneurysm repair (EVAR) and to compare contemporary AAA repair with the pre-EVAR era. Patients undergoing open AAA repair were identified; the demographics, outcomes, and indications for open repair were reviewed. Outcomes were compared based on indication for open repair in the EVAR era and between the pre-EVAR and EVAR eras. Open indications in the EVAR era included: age younger than 65 years with minimal comorbidities (AGE, n = 24 [9.8%]), unfavorable anatomy (ANAT, n = 146 [59.3%]), aortoiliac occlusive disease (AIOD, n = 38 [15.4%]), and miscellaneous (OTHER, n = 38 [15.4%]). Mortality (30-day and 5-year) was affected by indication: AGE = 0 and 0 per cent, ANAT = 4.1 and 49.7 per cent, AIOD = 13.5 and 32.3 per cent, and OTHER = 5.3 and 41.8 per cent. Ag...

Research paper thumbnail of Successful outcome" after below-knee amputation: An objective definition and influence of clinical variables

The American surgeon

Functional success after below-knee amputation (BKA) has been poorly studied. The purpose of this... more Functional success after below-knee amputation (BKA) has been poorly studied. The purpose of this study was to establish a consistent definition of "successful outcome" after BKA and to identify clinical variables influencing that definition. Three hundred nine consecutive patients undergoing BKA were evaluated postoperatively using the following definition for "successful outcome": 1) wound healing of the BKA without need for revision to a higher level; 2) maintenance of ambulation with a prosthesis for at least 1 year or until death; and 3) survival for at least 6 months. Independent clinical predictors influencing outcome were determined using bivariate and multivariable logistic regression analyses. For the cohort, median survival and maintenance of ambulation were 44 months and 60 months, respectively. Although 86.4 per cent of patients healed without the need for revision to a higher level, 63.4 per cent maintained ambulation with a prosthesis for 1 year an...

Research paper thumbnail of Contemporary outcomes of iliofemoral bypass grafting for unilateral aortoiliac occlusive disease: a 10-year experience

The American surgeon, 2008

Current treatment of complex aortoiliac occlusive disease (AIOD) includes the aortobifemoral bypa... more Current treatment of complex aortoiliac occlusive disease (AIOD) includes the aortobifemoral bypass or the femoral-femoral bypass. However, because of bilateral groin exposure and associated risks, there is a significant morbidity associated with these procedures. In appropriate patients with unilateral AIOD, the iliofemoral bypass graft (IFBPG) via a lower abdominal retroperitoneal incision can be an acceptable alternative. The purpose of this study is to review the safety and efficacy as well as long-term outcomes of IFBPG in patients with unilateral AIOD. From July 1997 through June 2006, 40 patients (64.3 +/- 11.2-years-old, range 41-89-years-old, 57.5% critical limb ischemia, 70% male, 95% smokers) with unilateral AIOD were treated with IFBPG. Perioperative complications and symptom resolution were measured and Kaplan-Meier life table analysis was used to analyze outcomes of primary and secondary patency, survival, limb salvage, contralateral intervention, and maintenance of am...

Research paper thumbnail of Emergent and elective colon surgery in the extreme elderly: do the results warrant the operation?

The American surgeon, 2008

With the elderly population rising continuously, surgeons are increasingly confronted by the dile... more With the elderly population rising continuously, surgeons are increasingly confronted by the dilemma of operative management in these patients, which frequently encompasses end-of-life issues. Increasing age and emergent surgery are known risk factors for poor outcomes in colon surgery. The purpose of this study is to delineate differences in outcomes between emergent and elective colon surgery and identify risk factors that can guide the surgeon in caring for the extreme elderly (age 80 years or older). From 2001 to 2006, a retrospective review of the resident database at Greenville Hospital System identified 104 extreme elderly patients who underwent colon surgery (65 elective, 39 emergent). Comparing elective and emergent operations, results showed substantial differences in morbidity (20% vs 51.2%, P < 0.001), 30-day mortality rate (7.7% vs 30.7%, P < 0.005), and length of stay (13.6 days vs 21.6 days, P < 0.004). Percentage of patients discharged to home was significan...

Research paper thumbnail of Does obesity predict functional outcome in the dysvascular amputee?

The American Surgeon, Aug 1, 2006

Limited information is available concerning the effects of obesity on the functional outcomes of ... more Limited information is available concerning the effects of obesity on the functional outcomes of patients requiring major lower limb amputation because of peripheral arterial disease (PAD). The purpose of this study was to examine the predictive ability of body mass index (BMI) to determine functional outcome in the dysvascular amputee. To do this, 434 consecutive patients (mean age, 65.8 +/- 13.3, 59% male, 71.4% diabetic) undergoing major limb amputation (225 below-knee amputation, 27 through-knee amputation, 132 above-knee amputation, and 50 bilateral) as a complication of PAD from January 1998 through May 2004 were analyzed according to preoperative BMI. BMI was classified according to the four-group Center for Disease Control system: underweight, 0 to 18.4 kg/m2; normal, 18.5 to 24.9 kg/m2; overweight, 25 to 29.9 kg/m2; and obese, > or = 30 kg/m2. Outcome parameters measured included prosthetic usage, maintenance of ambulation, survival, and maintenance of independent living status. The chi2 test for association was used to examine prosthesis wear. Kaplan-Meier curves were constructed to assess maintenance of ambulation, survival, and maintenance of independent living status. Multivariate analysis using the multiple logistic regression model and a Cox proportional hazards model were used to predict variables independently associated with prosthetic use and ambulation, survival, and independence, respectively. Overall prosthetic usage and 36-month ambulation, survival, and independent living status for the entire cohort was 48.6 per cent, 42.8 per cent, 48.1 per cent, 72.3 per cent, and for patients with normal BMI was 41.5 per cent, 37.4 per cent, 45.6 per cent, and 69.5 per cent, respectively. There was no statistically significant difference in outcomes for overweight patients (59.2%, 50.7%, 52.5%, and 75%) or obese patients (51.8%, 46.2%, 49.7%, and 75%) when compared with normal patients. Although there were significantly poorer outcomes for underweight patients for the parameters of prosthetic usage when compared with the remaining cohort (25%, P = 0.001) and maintenance of ambulation when compared with overweight patients (20.8%, P = 0.026), multivariate analysis adjusting for medical comorbidities and level of amputation showed that BMI was not a significant independent predictor of failure for any outcome parameter measured. In conclusion, BMI failed to correlate with functional outcome and, specifically, obesity did not predict a poorer prognosis.

Research paper thumbnail of Determinants of functional outcome after revascularization for critical limb ischemia: An analysis of 1000 consecutive vascular interventions

Journal of Vascular Surgery, 2006

When reporting standards for successful lower extremity revascularization were established, it wa... more When reporting standards for successful lower extremity revascularization were established, it was assumed that arterial reconstruction, patency, and limb salvage would correlate with the ultimate goal of therapy: improved functional performance. In reality, factors determining improvement of ambulation and maintenance of independent living status after revascularization have been poorly studied. The purpose of this study was to assess the important determinants of functional outcome for patients after intervention for critical limb ischemia. The results of 1000 revascularized limbs from 841 patients were studied. Indications were rest pain, 41.1%; ischemic ulceration, 35.6%; gangrene, 23.3%; infrainguinal, 70.9%; aortoiliac, 24.2%; and both, 4.9%. Treatment was by endovascular intervention, 35.5%; open surgery, 61.7%; and both, 2.8%. Patient were mean age of 68 +/- 12 years, and 56.6% were men, 74.7% were white, 54.2% had diabetes mellitus, 67% were smokers, 13.4% had end-stage renal disease and were on dialysis, and 36% had prior vascular surgery. Patients were treated with conventional therapy by fellowship-trained vascular specialists at a single center and were analyzed according to the type of intervention, the arterial level treated, age, race, gender, presentation, the presence of diabetes, smoking history, end-stage renal disease, coronary disease, hypertension, hyperlipidemia, obesity, chronic obstructive pulmonary disease, previous stroke, dementia, prior vascular surgery, preoperative ambulatory status, limb loss &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;or=1 year of treatment, and independent living status. The technical outcomes of reconstruction patency and limb salvage as well as the functional outcomes of survival, maintenance of ambulation, and independent living status were measured for each variable using Kaplan-Meier life-table analysis, and differences were assessed using the log-rank test. A Cox proportional hazards model was used to assess independent predictors of outcome and obtain adjusted hazard ratios and 95% confidence intervals. At 5 years, 72.4% of the entire cohort had a patent reconstruction and 72.1% had an intact limb. Overall 5-year functional outcomes were 41.9% for survival, 70.6% for maintenance of ambulation, and 81.3% for independent living status. Outcome was not significantly affected by the type of treatment (endovascular or open surgery) or by the level of disease treated (aortoiliac, infrainguinal, or both). The most important independent, statistically significant predictors of particularly poor functional outcome were impaired ambulatory ability at the time of presentation (70% 5-year mortality, hazard ratio, 3.34; 39.5% failure to eventually ambulate, hazard ratio, 2.83; 30% loss of independent living status, hazard ratio, 7.97), and the presence of dementia (73% late mortality, hazard ratio, 1.57; 41.2% failure to eventually ambulate, hazard ratio, 2.20; 46.4% loss of independent living status, hazard ratio, 5.44). These factors were even more predictive than limb amputation alone. Functional outcome for patients undergoing intervention for critical limb ischemia is not solely determined by the traditional measures of reconstruction patency and limb salvage, but also by certain intrinsic patient comorbidities at the time of presentation. These findings question the benefit of our current approach to critical limb ischemia in functionally impaired, chronically ill patients--patients who undoubtedly will be more prevalent as our population ages.

Research paper thumbnail of The role of the prosthetic axilloaxillary loop access as a tertiary arteriovenous access procedure

Journal of Vascular Surgery, 2008

Purpose: In the last decade, the Dialysis Outcome Quality Initiative (DOQI) Guidelines have enhan... more Purpose: In the last decade, the Dialysis Outcome Quality Initiative (DOQI) Guidelines have enhanced the longevity of patients with end-stage renal disease (ESRD) on hemodialysis. Consequently, surgeons are increasingly challenged to provide vascular access for patients in whom options for access in the upper extremity have been expended. This situation is even more problematic in the morbidly obese patient on hemodialysis. Our group previously reported a high rate of infection and need for secondary interventions in obese patients with prosthetic femorofemoral accesses. We now report a series of patients who underwent placement of a prosthetic axilloaxillary loop access. This study presents our technique and evaluates our results, particularly as they relate to the obese patient. Methods: From January 1998 to May 2006, 34 prosthetic axilloaxillary loop accesses were placed in 32 patients with ESRD. Eleven patients (12 accesses) were obese, as defined by a body mass index >30 kg/m 2 . Median follow-up was 16 months. Kaplan-Meier analysis was used to determine primary and secondary patency as well as patient survival for the entire cohort and for the obese and nonobese patient cohorts. Survival curves were compared using the log-rank test for equality over strata. Results: The secondary patency rate was 59% at 1 year (median, 18 months). The 1-year patient survival was 69%. Infection occurred in 15% patients. Comparison of the obese vs nonobese cohorts demonstrated no statistically significant difference in 1-year primary patency (36% vs 10%, P ‫؍‬ .17) or secondary patency (71% vs 65%, P ‫؍‬ .34). There were no infections in the obese cohort. Conclusion: These data show that the prosthetic axilloaxillary loop access has acceptable outcomes and should be considered the tertiary vascular access procedure of choice in the obese patient on hemodialysis. ( J Vasc Surg 2008;48: 389-93.)

Research paper thumbnail of Surgical Revascularization in Patients with End-Stage Renal Disease: Results Using a New Paradigm in Outcomes Assessment

Journal of Vascular Surgery, 2008

et al. Circulation 2007;116(suppl I):I-98-105. Conclusion: Remote ischemic preconditioning (RIPC)... more et al. Circulation 2007;116(suppl I):I-98-105. Conclusion: Remote ischemic preconditioning (RIPC) reduces postoperative myocardial injury, myocardial infarction, and renal impairment in patients undergoing elective open abdominal aortic aneurysm (AAA) repair.

Research paper thumbnail of Clinical success using patient-oriented outcome measures after lower extremity bypass and endovascular intervention for ischemic tissue loss

Journal of Vascular Surgery, 2009

Introduction: Successful outcome after lower extremity revascularization is usually measured by p... more Introduction: Successful outcome after lower extremity revascularization is usually measured by physician-oriented terms such as graft patency and amputation-free survival. It has been increasingly appreciated that these criteria do not necessarily translate into success from the prospective of the patient. The purpose of this study, therefore, is to retrospectively examine success after lower extremity revascularization for tissue loss using patient-oriented measures and to include patients who underwent both open surgical bypass and endovascular therapy. Methods: Between 1998 and 2005, 677 patients (316 endovascular and 361 open surgery) underwent revascularization for ischemic tissue loss. The method of revascularization (endovascular or open surgery) was left to the discretion of the surgeon. Revascularization was considered to be clinically successful if each of the following occurred: reconstruction patency until wound healing, limb salvage for 1 year, maintenance of ambulation for 1 year, and survival for 6 months. The influence of 20 intrinsic patient factors, including type of revascularization (open vs endo) was examined using the 2 test. Significant factors in bivariate analysis were included in a logistic regression model to determine independent predictors and probability of failure. Results: Overall clinical success was achieved in 277 (40.9%) patients. Success for open surgical and endovascular cohorts was 44.3% and 37.0%, respectively (P ‫؍‬ .

Research paper thumbnail of Through-knee amputation in patients with peripheral arterial disease: A review of 50 cases

Journal of Vascular Surgery, 2008

Background: For good rehabilitation candidates, the biomechanical advantages of the end weight-be... more Background: For good rehabilitation candidates, the biomechanical advantages of the end weight-bearing through-knee amputation (TKAmp) compared with the above knee amputation (AKA) are well established. However, the TKAmp has been abandoned by vascular surgeons because of poor wound healing rates related to long tissue flaps and challenges to prosthetic fitting related to the femoral condyles. Since 1998, we have performed the modified "Mazet" technique TKAmp procedure that creates shorter flaps to close the wound and greatly facilitates prosthesis fitting. The purpose of this study is to review our results with TKAmp in patients with peripheral vascular disease who were not candidates for below-knee amputation. Methods: The records of all patients who underwent through-knee amputation between 1998 and 2006 were retrospectively reviewed. Mean follow-up was 33 months (range, 38 days to 99 months). Amputations for trauma and malignancy were excluded. Patient survival, maintenance of ambulation, and independent living status were analyzed using Kaplan-Meier survival analysis methods. Results: Fifty patients underwent TKAmp using a modified Mazet technique. The mean age was 63 years; 50% were men, and 50% had diabetes mellitus. All patients had peripheral arterial disease. Thirty-five patients (70%) had prior revascularization procedures. Those patients averaged 2.2 revascularization procedures prior to amputation. There were three (6%) perioperative deaths. The ipsilateral common femoral artery was patent in 43/50 (86%) of patients at the time of amputation. Forty patients (80%) had open wounds and three patients (6%) had a failed below-knee amputation at the time of TKAmp. Thirty-eight patients (81%) healed their TKAmp wound. Nine patients failed to heal and were revised to an above knee amputation. The cumulative probability of regular prosthetic usage and maintenance of ambulation was estimated to be 0.56 at 3 years and 0.41 at 5 years. The probability of maintaining independent living status at 3 and 5 years was 0.77 and 0.65, respectively. Survival probabilities for patients in this series were 0.60 at 3 years and 0.44 at 5 years. Conclusion: These data show that the TKAmp is associated with an acceptable primary healing rate and satisfactory functional outcomes in patients with peripheral arterial disease. The advantages of TKAmp over AKA make it the preferred alternative for patients with vascular disease who are candidates for prosthetic rehabilitation. ( J Vasc Surg 2008;48:638-43.)

Research paper thumbnail of Do Current Outcomes Justify More Liberal Use of Revascularization for Vasculogenic Claudication? A Single Center Experience of 1,000 Consecutively Treated Limbs

Journal of the American College of Surgeons, 2008

the occurrence of clinically evident cerebral hyperperfusion. Crossed cerebellar hypoperfusion (C... more the occurrence of clinically evident cerebral hyperperfusion. Crossed cerebellar hypoperfusion (CCH) is a reduction in blood flow in the cerebellar hemisphere contralateral to a supertentorial lesion. This phenomenon can be seen after CEA. The authors sought to clarify the significance of postoperative CCH in patients with cerebral hyperperfusion using SPECT scanning and tests of cognitive impairment.

Research paper thumbnail of Critical Analysis of Clinical Success after Surgical Bypass for Lower-Extremity Ischemic Tissue Loss Using a Standardized Definition Combining Multiple Parameters: A New Paradigm of Outcomes Assessment

Journal of the American College of Surgeons, 2007

Success after surgical revascularization of the lower extremities, traditionally defined by graft... more Success after surgical revascularization of the lower extremities, traditionally defined by graft patency or limb salvage, fails to consider other intuitive measures of importance. The purpose of the study was to construct a more comprehensive definition of clinical success and to identify clinical predictors of failure. For the purpose of this study, clinical success was defined as achieving all of the following criteria: graft patency to the point of wound healing; limb salvage for 1 year; maintenance of ambulatory status for 1 year; and survival for 6 months. Between 1998 and 2004, 331 consecutive patients undergoing bypass for Rutherford III critical limb ischemia were measured for clinical success. Bivariate and logistic regression analyses were performed to determine demographic differences between success and failure. Despite achieving acceptable graft patency (72.7% at 36 months) and limb salvage (73.3% at 36 months), clinical success combining all 4 defined parameters was only 44.4%. Independent predictors of failure included impaired ambulatory status at presentation (odds ratio [OR] = 6.44), presence of infrainguinal disease (OR = 3.93), end-stage renal disease (OR = 2.48), presence of gangrene (OR = 2.40), and hyperlipidemia (OR = 0.56). Probability of failure in patients possessing every predictor except hyperlipidemia at presentation was 97% (OR = 150.6). Despite achieving acceptable graft patency and limb salvage, fewer than half of the patients achieved success when using a definition combining multiple parameters. A reappraisal of our current approach to critical limb ischemia in certain high-risk patients is warranted.

Research paper thumbnail of Fistula Elevation Procedure: Experience with 295 Consecutive Cases During a 7-Year Period

Journal of the American College of Surgeons, 2008

the occurrence of clinically evident cerebral hyperperfusion. Crossed cerebellar hypoperfusion (C... more the occurrence of clinically evident cerebral hyperperfusion. Crossed cerebellar hypoperfusion (CCH) is a reduction in blood flow in the cerebellar hemisphere contralateral to a supertentorial lesion. This phenomenon can be seen after CEA. The authors sought to clarify the significance of postoperative CCH in patients with cerebral hyperperfusion using SPECT scanning and tests of cognitive impairment.

Research paper thumbnail of Feasibility Study of a Mid-Level Developmental-Behavioral Pediatric Assessment

Journal of Developmental & Behavioral Pediatrics, 2006

Research paper thumbnail of Identification of device-associated infections utilizing administrative data

American Journal of Infection Control, 2013

Health care-associated infections are a cause of significant morbidity and mortality in US hospit... more Health care-associated infections are a cause of significant morbidity and mortality in US hospitals. Recent changes have broadened the scope of health care-associated infections surveillance data to use in public reporting and of administrative data for determining Medicare reimbursement adjustments for hospital-acquired conditions. Infection surveillance results for catheter-associated urinary tract infections (CAUTI), central line-associated bloodstream infections (CLABSI), and ventilator-associated pneumonia were compared with infections identified by hospital administrative data. The sensitivity and specificity of administrative data were calculated, with surveillance data considered the gold standard. The sensitivity of administrative data diagnosis codes for CAUTI, CLABSI, and ventilator-associated pneumonia were 0%, 21%, and 25%, respectively. The incorporation of additional diagnosis codes in definitions increased the sensitivity of administrative data somewhat with little decrease in specificity. Positive predictive values for definitions corresponding to Centers for Medicare and Medicaid services-defined hospital-acquired conditions were 0% for CAUTI and 41% for CLABSI. Although infection surveillance methods and administrative data are widely used as tools to identify health care-associated infections, in our study administrative data failed to identify the same infections that were detected by surveillance. Hospitals, already incentivized by the use of performance measures to improve the quality of patient care, should also recognize the need for ongoing scrutiny of appropriate quality measures.

Research paper thumbnail of The Reverse J Arteriovenous Graft Configuration for Hemodialysis Access : Rationale, Technique, and Outcomes. Discussion

The American Surgeon, Jul 1, 2008

The long-term survival of patients on hemodialysis is often limited by the exhaustion of vascular... more The long-term survival of patients on hemodialysis is often limited by the exhaustion of vascular access sites. A fundamental principle of vascular access surgery is that the arteriovenous (AV) access be placed as far distally in the arm as possible. This principle enhances the secondary patency of the AV grafts by preserving the proximal veins for AV graft revision and provides venous outflow for a new AV access to be placed more proximally in the extremity. The standard straight and looped AV graft configurations violate this principle by bypassing long segments of vein in the extremity that could be used for AV graft revision or new AV graft placement. We have developed a novel AV graft configuration that preserves venous outflow and enhances the longevity of each AV access site. The purpose of this review is to describe the reverse J AV graft technique and to report our outcomes with the procedure. Between February 2004 and April 2007, 26 AV grafts were placed using the reverse J configuration. Eighteen (69%) AV grafts were placed in the upper arm, 7 (27%) were placed in the forearm, and 1 (4%) was placed in the thigh. Median follow-up was 320 days. The secondary AV graft patency was 90 per cent at 6 months, 84 per cent at 12 months, and 84 per cent at 18 months. Five AV grafts were subsequently revised to a loop configuration. Overall patient survival was 85 per cent at 6 months, 68 per cent at 12 months, and 62 per cent at 18 months. Compared with the standard straight and looped AV graft configurations, the reverse J AV graft configuration preserves the length of venous outflow in the extremity for AV graft revision or new AV graft placement. Therefore, the reverse J configuration enhances the secondary patency of AV graft patency and AV access site longevity.

Research paper thumbnail of Changing indications and outcomes for open abdominal aortic aneurysm repair since the advent of endovascular repair

The American surgeon, 2009

The indications for open abdominal aortic aneurysm (AAA) repair have changed with the development... more The indications for open abdominal aortic aneurysm (AAA) repair have changed with the development of endovascular techniques. The purpose of this study is to clarify the indications and outcomes for open repair since endovascular aneurysm repair (EVAR) and to compare contemporary AAA repair with the pre-EVAR era. Patients undergoing open AAA repair were identified; the demographics, outcomes, and indications for open repair were reviewed. Outcomes were compared based on indication for open repair in the EVAR era and between the pre-EVAR and EVAR eras. Open indications in the EVAR era included: age younger than 65 years with minimal comorbidities (AGE, n = 24 [9.8%]), unfavorable anatomy (ANAT, n = 146 [59.3%]), aortoiliac occlusive disease (AIOD, n = 38 [15.4%]), and miscellaneous (OTHER, n = 38 [15.4%]). Mortality (30-day and 5-year) was affected by indication: AGE = 0 and 0 per cent, ANAT = 4.1 and 49.7 per cent, AIOD = 13.5 and 32.3 per cent, and OTHER = 5.3 and 41.8 per cent. Ag...

Research paper thumbnail of Successful outcome" after below-knee amputation: An objective definition and influence of clinical variables

The American surgeon

Functional success after below-knee amputation (BKA) has been poorly studied. The purpose of this... more Functional success after below-knee amputation (BKA) has been poorly studied. The purpose of this study was to establish a consistent definition of "successful outcome" after BKA and to identify clinical variables influencing that definition. Three hundred nine consecutive patients undergoing BKA were evaluated postoperatively using the following definition for "successful outcome": 1) wound healing of the BKA without need for revision to a higher level; 2) maintenance of ambulation with a prosthesis for at least 1 year or until death; and 3) survival for at least 6 months. Independent clinical predictors influencing outcome were determined using bivariate and multivariable logistic regression analyses. For the cohort, median survival and maintenance of ambulation were 44 months and 60 months, respectively. Although 86.4 per cent of patients healed without the need for revision to a higher level, 63.4 per cent maintained ambulation with a prosthesis for 1 year an...

Research paper thumbnail of Contemporary outcomes of iliofemoral bypass grafting for unilateral aortoiliac occlusive disease: a 10-year experience

The American surgeon, 2008

Current treatment of complex aortoiliac occlusive disease (AIOD) includes the aortobifemoral bypa... more Current treatment of complex aortoiliac occlusive disease (AIOD) includes the aortobifemoral bypass or the femoral-femoral bypass. However, because of bilateral groin exposure and associated risks, there is a significant morbidity associated with these procedures. In appropriate patients with unilateral AIOD, the iliofemoral bypass graft (IFBPG) via a lower abdominal retroperitoneal incision can be an acceptable alternative. The purpose of this study is to review the safety and efficacy as well as long-term outcomes of IFBPG in patients with unilateral AIOD. From July 1997 through June 2006, 40 patients (64.3 +/- 11.2-years-old, range 41-89-years-old, 57.5% critical limb ischemia, 70% male, 95% smokers) with unilateral AIOD were treated with IFBPG. Perioperative complications and symptom resolution were measured and Kaplan-Meier life table analysis was used to analyze outcomes of primary and secondary patency, survival, limb salvage, contralateral intervention, and maintenance of am...

Research paper thumbnail of Emergent and elective colon surgery in the extreme elderly: do the results warrant the operation?

The American surgeon, 2008

With the elderly population rising continuously, surgeons are increasingly confronted by the dile... more With the elderly population rising continuously, surgeons are increasingly confronted by the dilemma of operative management in these patients, which frequently encompasses end-of-life issues. Increasing age and emergent surgery are known risk factors for poor outcomes in colon surgery. The purpose of this study is to delineate differences in outcomes between emergent and elective colon surgery and identify risk factors that can guide the surgeon in caring for the extreme elderly (age 80 years or older). From 2001 to 2006, a retrospective review of the resident database at Greenville Hospital System identified 104 extreme elderly patients who underwent colon surgery (65 elective, 39 emergent). Comparing elective and emergent operations, results showed substantial differences in morbidity (20% vs 51.2%, P < 0.001), 30-day mortality rate (7.7% vs 30.7%, P < 0.005), and length of stay (13.6 days vs 21.6 days, P < 0.004). Percentage of patients discharged to home was significan...

Research paper thumbnail of Does obesity predict functional outcome in the dysvascular amputee?

The American Surgeon, Aug 1, 2006

Limited information is available concerning the effects of obesity on the functional outcomes of ... more Limited information is available concerning the effects of obesity on the functional outcomes of patients requiring major lower limb amputation because of peripheral arterial disease (PAD). The purpose of this study was to examine the predictive ability of body mass index (BMI) to determine functional outcome in the dysvascular amputee. To do this, 434 consecutive patients (mean age, 65.8 +/- 13.3, 59% male, 71.4% diabetic) undergoing major limb amputation (225 below-knee amputation, 27 through-knee amputation, 132 above-knee amputation, and 50 bilateral) as a complication of PAD from January 1998 through May 2004 were analyzed according to preoperative BMI. BMI was classified according to the four-group Center for Disease Control system: underweight, 0 to 18.4 kg/m2; normal, 18.5 to 24.9 kg/m2; overweight, 25 to 29.9 kg/m2; and obese, > or = 30 kg/m2. Outcome parameters measured included prosthetic usage, maintenance of ambulation, survival, and maintenance of independent living status. The chi2 test for association was used to examine prosthesis wear. Kaplan-Meier curves were constructed to assess maintenance of ambulation, survival, and maintenance of independent living status. Multivariate analysis using the multiple logistic regression model and a Cox proportional hazards model were used to predict variables independently associated with prosthetic use and ambulation, survival, and independence, respectively. Overall prosthetic usage and 36-month ambulation, survival, and independent living status for the entire cohort was 48.6 per cent, 42.8 per cent, 48.1 per cent, 72.3 per cent, and for patients with normal BMI was 41.5 per cent, 37.4 per cent, 45.6 per cent, and 69.5 per cent, respectively. There was no statistically significant difference in outcomes for overweight patients (59.2%, 50.7%, 52.5%, and 75%) or obese patients (51.8%, 46.2%, 49.7%, and 75%) when compared with normal patients. Although there were significantly poorer outcomes for underweight patients for the parameters of prosthetic usage when compared with the remaining cohort (25%, P = 0.001) and maintenance of ambulation when compared with overweight patients (20.8%, P = 0.026), multivariate analysis adjusting for medical comorbidities and level of amputation showed that BMI was not a significant independent predictor of failure for any outcome parameter measured. In conclusion, BMI failed to correlate with functional outcome and, specifically, obesity did not predict a poorer prognosis.

Research paper thumbnail of Determinants of functional outcome after revascularization for critical limb ischemia: An analysis of 1000 consecutive vascular interventions

Journal of Vascular Surgery, 2006

When reporting standards for successful lower extremity revascularization were established, it wa... more When reporting standards for successful lower extremity revascularization were established, it was assumed that arterial reconstruction, patency, and limb salvage would correlate with the ultimate goal of therapy: improved functional performance. In reality, factors determining improvement of ambulation and maintenance of independent living status after revascularization have been poorly studied. The purpose of this study was to assess the important determinants of functional outcome for patients after intervention for critical limb ischemia. The results of 1000 revascularized limbs from 841 patients were studied. Indications were rest pain, 41.1%; ischemic ulceration, 35.6%; gangrene, 23.3%; infrainguinal, 70.9%; aortoiliac, 24.2%; and both, 4.9%. Treatment was by endovascular intervention, 35.5%; open surgery, 61.7%; and both, 2.8%. Patient were mean age of 68 +/- 12 years, and 56.6% were men, 74.7% were white, 54.2% had diabetes mellitus, 67% were smokers, 13.4% had end-stage renal disease and were on dialysis, and 36% had prior vascular surgery. Patients were treated with conventional therapy by fellowship-trained vascular specialists at a single center and were analyzed according to the type of intervention, the arterial level treated, age, race, gender, presentation, the presence of diabetes, smoking history, end-stage renal disease, coronary disease, hypertension, hyperlipidemia, obesity, chronic obstructive pulmonary disease, previous stroke, dementia, prior vascular surgery, preoperative ambulatory status, limb loss &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;or=1 year of treatment, and independent living status. The technical outcomes of reconstruction patency and limb salvage as well as the functional outcomes of survival, maintenance of ambulation, and independent living status were measured for each variable using Kaplan-Meier life-table analysis, and differences were assessed using the log-rank test. A Cox proportional hazards model was used to assess independent predictors of outcome and obtain adjusted hazard ratios and 95% confidence intervals. At 5 years, 72.4% of the entire cohort had a patent reconstruction and 72.1% had an intact limb. Overall 5-year functional outcomes were 41.9% for survival, 70.6% for maintenance of ambulation, and 81.3% for independent living status. Outcome was not significantly affected by the type of treatment (endovascular or open surgery) or by the level of disease treated (aortoiliac, infrainguinal, or both). The most important independent, statistically significant predictors of particularly poor functional outcome were impaired ambulatory ability at the time of presentation (70% 5-year mortality, hazard ratio, 3.34; 39.5% failure to eventually ambulate, hazard ratio, 2.83; 30% loss of independent living status, hazard ratio, 7.97), and the presence of dementia (73% late mortality, hazard ratio, 1.57; 41.2% failure to eventually ambulate, hazard ratio, 2.20; 46.4% loss of independent living status, hazard ratio, 5.44). These factors were even more predictive than limb amputation alone. Functional outcome for patients undergoing intervention for critical limb ischemia is not solely determined by the traditional measures of reconstruction patency and limb salvage, but also by certain intrinsic patient comorbidities at the time of presentation. These findings question the benefit of our current approach to critical limb ischemia in functionally impaired, chronically ill patients--patients who undoubtedly will be more prevalent as our population ages.

Research paper thumbnail of The role of the prosthetic axilloaxillary loop access as a tertiary arteriovenous access procedure

Journal of Vascular Surgery, 2008

Purpose: In the last decade, the Dialysis Outcome Quality Initiative (DOQI) Guidelines have enhan... more Purpose: In the last decade, the Dialysis Outcome Quality Initiative (DOQI) Guidelines have enhanced the longevity of patients with end-stage renal disease (ESRD) on hemodialysis. Consequently, surgeons are increasingly challenged to provide vascular access for patients in whom options for access in the upper extremity have been expended. This situation is even more problematic in the morbidly obese patient on hemodialysis. Our group previously reported a high rate of infection and need for secondary interventions in obese patients with prosthetic femorofemoral accesses. We now report a series of patients who underwent placement of a prosthetic axilloaxillary loop access. This study presents our technique and evaluates our results, particularly as they relate to the obese patient. Methods: From January 1998 to May 2006, 34 prosthetic axilloaxillary loop accesses were placed in 32 patients with ESRD. Eleven patients (12 accesses) were obese, as defined by a body mass index >30 kg/m 2 . Median follow-up was 16 months. Kaplan-Meier analysis was used to determine primary and secondary patency as well as patient survival for the entire cohort and for the obese and nonobese patient cohorts. Survival curves were compared using the log-rank test for equality over strata. Results: The secondary patency rate was 59% at 1 year (median, 18 months). The 1-year patient survival was 69%. Infection occurred in 15% patients. Comparison of the obese vs nonobese cohorts demonstrated no statistically significant difference in 1-year primary patency (36% vs 10%, P ‫؍‬ .17) or secondary patency (71% vs 65%, P ‫؍‬ .34). There were no infections in the obese cohort. Conclusion: These data show that the prosthetic axilloaxillary loop access has acceptable outcomes and should be considered the tertiary vascular access procedure of choice in the obese patient on hemodialysis. ( J Vasc Surg 2008;48: 389-93.)

Research paper thumbnail of Surgical Revascularization in Patients with End-Stage Renal Disease: Results Using a New Paradigm in Outcomes Assessment

Journal of Vascular Surgery, 2008

et al. Circulation 2007;116(suppl I):I-98-105. Conclusion: Remote ischemic preconditioning (RIPC)... more et al. Circulation 2007;116(suppl I):I-98-105. Conclusion: Remote ischemic preconditioning (RIPC) reduces postoperative myocardial injury, myocardial infarction, and renal impairment in patients undergoing elective open abdominal aortic aneurysm (AAA) repair.

Research paper thumbnail of Clinical success using patient-oriented outcome measures after lower extremity bypass and endovascular intervention for ischemic tissue loss

Journal of Vascular Surgery, 2009

Introduction: Successful outcome after lower extremity revascularization is usually measured by p... more Introduction: Successful outcome after lower extremity revascularization is usually measured by physician-oriented terms such as graft patency and amputation-free survival. It has been increasingly appreciated that these criteria do not necessarily translate into success from the prospective of the patient. The purpose of this study, therefore, is to retrospectively examine success after lower extremity revascularization for tissue loss using patient-oriented measures and to include patients who underwent both open surgical bypass and endovascular therapy. Methods: Between 1998 and 2005, 677 patients (316 endovascular and 361 open surgery) underwent revascularization for ischemic tissue loss. The method of revascularization (endovascular or open surgery) was left to the discretion of the surgeon. Revascularization was considered to be clinically successful if each of the following occurred: reconstruction patency until wound healing, limb salvage for 1 year, maintenance of ambulation for 1 year, and survival for 6 months. The influence of 20 intrinsic patient factors, including type of revascularization (open vs endo) was examined using the 2 test. Significant factors in bivariate analysis were included in a logistic regression model to determine independent predictors and probability of failure. Results: Overall clinical success was achieved in 277 (40.9%) patients. Success for open surgical and endovascular cohorts was 44.3% and 37.0%, respectively (P ‫؍‬ .

Research paper thumbnail of Through-knee amputation in patients with peripheral arterial disease: A review of 50 cases

Journal of Vascular Surgery, 2008

Background: For good rehabilitation candidates, the biomechanical advantages of the end weight-be... more Background: For good rehabilitation candidates, the biomechanical advantages of the end weight-bearing through-knee amputation (TKAmp) compared with the above knee amputation (AKA) are well established. However, the TKAmp has been abandoned by vascular surgeons because of poor wound healing rates related to long tissue flaps and challenges to prosthetic fitting related to the femoral condyles. Since 1998, we have performed the modified "Mazet" technique TKAmp procedure that creates shorter flaps to close the wound and greatly facilitates prosthesis fitting. The purpose of this study is to review our results with TKAmp in patients with peripheral vascular disease who were not candidates for below-knee amputation. Methods: The records of all patients who underwent through-knee amputation between 1998 and 2006 were retrospectively reviewed. Mean follow-up was 33 months (range, 38 days to 99 months). Amputations for trauma and malignancy were excluded. Patient survival, maintenance of ambulation, and independent living status were analyzed using Kaplan-Meier survival analysis methods. Results: Fifty patients underwent TKAmp using a modified Mazet technique. The mean age was 63 years; 50% were men, and 50% had diabetes mellitus. All patients had peripheral arterial disease. Thirty-five patients (70%) had prior revascularization procedures. Those patients averaged 2.2 revascularization procedures prior to amputation. There were three (6%) perioperative deaths. The ipsilateral common femoral artery was patent in 43/50 (86%) of patients at the time of amputation. Forty patients (80%) had open wounds and three patients (6%) had a failed below-knee amputation at the time of TKAmp. Thirty-eight patients (81%) healed their TKAmp wound. Nine patients failed to heal and were revised to an above knee amputation. The cumulative probability of regular prosthetic usage and maintenance of ambulation was estimated to be 0.56 at 3 years and 0.41 at 5 years. The probability of maintaining independent living status at 3 and 5 years was 0.77 and 0.65, respectively. Survival probabilities for patients in this series were 0.60 at 3 years and 0.44 at 5 years. Conclusion: These data show that the TKAmp is associated with an acceptable primary healing rate and satisfactory functional outcomes in patients with peripheral arterial disease. The advantages of TKAmp over AKA make it the preferred alternative for patients with vascular disease who are candidates for prosthetic rehabilitation. ( J Vasc Surg 2008;48:638-43.)

Research paper thumbnail of Do Current Outcomes Justify More Liberal Use of Revascularization for Vasculogenic Claudication? A Single Center Experience of 1,000 Consecutively Treated Limbs

Journal of the American College of Surgeons, 2008

the occurrence of clinically evident cerebral hyperperfusion. Crossed cerebellar hypoperfusion (C... more the occurrence of clinically evident cerebral hyperperfusion. Crossed cerebellar hypoperfusion (CCH) is a reduction in blood flow in the cerebellar hemisphere contralateral to a supertentorial lesion. This phenomenon can be seen after CEA. The authors sought to clarify the significance of postoperative CCH in patients with cerebral hyperperfusion using SPECT scanning and tests of cognitive impairment.

Research paper thumbnail of Critical Analysis of Clinical Success after Surgical Bypass for Lower-Extremity Ischemic Tissue Loss Using a Standardized Definition Combining Multiple Parameters: A New Paradigm of Outcomes Assessment

Journal of the American College of Surgeons, 2007

Success after surgical revascularization of the lower extremities, traditionally defined by graft... more Success after surgical revascularization of the lower extremities, traditionally defined by graft patency or limb salvage, fails to consider other intuitive measures of importance. The purpose of the study was to construct a more comprehensive definition of clinical success and to identify clinical predictors of failure. For the purpose of this study, clinical success was defined as achieving all of the following criteria: graft patency to the point of wound healing; limb salvage for 1 year; maintenance of ambulatory status for 1 year; and survival for 6 months. Between 1998 and 2004, 331 consecutive patients undergoing bypass for Rutherford III critical limb ischemia were measured for clinical success. Bivariate and logistic regression analyses were performed to determine demographic differences between success and failure. Despite achieving acceptable graft patency (72.7% at 36 months) and limb salvage (73.3% at 36 months), clinical success combining all 4 defined parameters was only 44.4%. Independent predictors of failure included impaired ambulatory status at presentation (odds ratio [OR] = 6.44), presence of infrainguinal disease (OR = 3.93), end-stage renal disease (OR = 2.48), presence of gangrene (OR = 2.40), and hyperlipidemia (OR = 0.56). Probability of failure in patients possessing every predictor except hyperlipidemia at presentation was 97% (OR = 150.6). Despite achieving acceptable graft patency and limb salvage, fewer than half of the patients achieved success when using a definition combining multiple parameters. A reappraisal of our current approach to critical limb ischemia in certain high-risk patients is warranted.

Research paper thumbnail of Fistula Elevation Procedure: Experience with 295 Consecutive Cases During a 7-Year Period

Journal of the American College of Surgeons, 2008

the occurrence of clinically evident cerebral hyperperfusion. Crossed cerebellar hypoperfusion (C... more the occurrence of clinically evident cerebral hyperperfusion. Crossed cerebellar hypoperfusion (CCH) is a reduction in blood flow in the cerebellar hemisphere contralateral to a supertentorial lesion. This phenomenon can be seen after CEA. The authors sought to clarify the significance of postoperative CCH in patients with cerebral hyperperfusion using SPECT scanning and tests of cognitive impairment.

Research paper thumbnail of Feasibility Study of a Mid-Level Developmental-Behavioral Pediatric Assessment

Journal of Developmental & Behavioral Pediatrics, 2006

Research paper thumbnail of Identification of device-associated infections utilizing administrative data

American Journal of Infection Control, 2013

Health care-associated infections are a cause of significant morbidity and mortality in US hospit... more Health care-associated infections are a cause of significant morbidity and mortality in US hospitals. Recent changes have broadened the scope of health care-associated infections surveillance data to use in public reporting and of administrative data for determining Medicare reimbursement adjustments for hospital-acquired conditions. Infection surveillance results for catheter-associated urinary tract infections (CAUTI), central line-associated bloodstream infections (CLABSI), and ventilator-associated pneumonia were compared with infections identified by hospital administrative data. The sensitivity and specificity of administrative data were calculated, with surveillance data considered the gold standard. The sensitivity of administrative data diagnosis codes for CAUTI, CLABSI, and ventilator-associated pneumonia were 0%, 21%, and 25%, respectively. The incorporation of additional diagnosis codes in definitions increased the sensitivity of administrative data somewhat with little decrease in specificity. Positive predictive values for definitions corresponding to Centers for Medicare and Medicaid services-defined hospital-acquired conditions were 0% for CAUTI and 41% for CLABSI. Although infection surveillance methods and administrative data are widely used as tools to identify health care-associated infections, in our study administrative data failed to identify the same infections that were detected by surveillance. Hospitals, already incentivized by the use of performance measures to improve the quality of patient care, should also recognize the need for ongoing scrutiny of appropriate quality measures.

Research paper thumbnail of The Reverse J Arteriovenous Graft Configuration for Hemodialysis Access : Rationale, Technique, and Outcomes. Discussion

The American Surgeon, Jul 1, 2008

The long-term survival of patients on hemodialysis is often limited by the exhaustion of vascular... more The long-term survival of patients on hemodialysis is often limited by the exhaustion of vascular access sites. A fundamental principle of vascular access surgery is that the arteriovenous (AV) access be placed as far distally in the arm as possible. This principle enhances the secondary patency of the AV grafts by preserving the proximal veins for AV graft revision and provides venous outflow for a new AV access to be placed more proximally in the extremity. The standard straight and looped AV graft configurations violate this principle by bypassing long segments of vein in the extremity that could be used for AV graft revision or new AV graft placement. We have developed a novel AV graft configuration that preserves venous outflow and enhances the longevity of each AV access site. The purpose of this review is to describe the reverse J AV graft technique and to report our outcomes with the procedure. Between February 2004 and April 2007, 26 AV grafts were placed using the reverse J configuration. Eighteen (69%) AV grafts were placed in the upper arm, 7 (27%) were placed in the forearm, and 1 (4%) was placed in the thigh. Median follow-up was 320 days. The secondary AV graft patency was 90 per cent at 6 months, 84 per cent at 12 months, and 84 per cent at 18 months. Five AV grafts were subsequently revised to a loop configuration. Overall patient survival was 85 per cent at 6 months, 68 per cent at 12 months, and 62 per cent at 18 months. Compared with the standard straight and looped AV graft configurations, the reverse J AV graft configuration preserves the length of venous outflow in the extremity for AV graft revision or new AV graft placement. Therefore, the reverse J configuration enhances the secondary patency of AV graft patency and AV access site longevity.