Miltos Lazarides - Academia.edu (original) (raw)

Papers by Miltos Lazarides

Research paper thumbnail of Factors affecting the lifespan of autologous and synthetic arteriovenous access routes for haemodialysis

The European journal of surgery = Acta chirurgica, 1996

To try and establish a consensus about the ideal secondary access for haemodialysis by assessing ... more To try and establish a consensus about the ideal secondary access for haemodialysis by assessing factors that affect the longevity of various access routes. Multicentre survey, by questionnaire. General hospital, Athens. All 1516 patients in the Athens area receiving chronic haemodialysis. Longevity of present and any previous access routes (n = 2323). Data including type of access, age, sex and the existence of diabetes, hypertension, hyperlipidaemia, or other systematic diseases were recorded. Some 1220 (80%) of the patients were using autologous access, 1049 (69%) arteriovenous (AV) fistulas at wrist and 171 (11%) at elbow. Variables were analysed using Cox's proportional hazard model. Age and female sex were significantly associated with failure of autogenous access (p < 0.001) although not affecting synthetic grafts. Autogenous fistula at the elbow was the only secondary access that was less likely to fail than the initial (baseline) fistula at the wrist. Among the vario...

Research paper thumbnail of Effects of limited work hours on surgical training

BACKGROUND: Legal mandates to reduce resident work hours have prompted changes in the structure o... more BACKGROUND: Legal mandates to reduce resident work hours have prompted changes in the structure of surgical training programs. Such changes have included modification of on-call schedules and the adoption of "night float" resident coverage. Little is known about the effects of these changes on surgical resident education and perceptions of quality of patient care. STUDY DESIGN: The surgical housestaff and faculty at a single institution completed a 21-point Likert survey. Subjects were asked to compare parameters of resident education, patient care, and resident quality of life before and after institution of a strict 80-hour work week resident training schedule. The number of hours worked per week before and after these changes were reported. American Board of Surgery In-Training Examination (ABSITE) scores were compared for the 2 years before and after implementation of this schedule. Total number of surgical cases performed by graduating chief residents were recorded and compared for the 3 years before and after the schedule changes. RESULTS: Resident work hours reduced significantly after schedule changes were implemented. A majority of surgical residents reported an improvement in quality of life, but residents and faculty perceived changes to have a negative impact on continuity of patient care. Mean ABSITE composite percentile scores significantly improved after the reduction of working hours. AB-SITE scores for junior residents improved significantly; no significant differences were noted in scores for senior residents. CONCLUSIONS: Reduction in resident work hours has salutary effects on perception of quality of life and basic education for surgical residents. These benefits may come at the expense of patient care, particularly continuity of care. This study did not directly assess patient outcomes but the perceptions of caregivers suggest that patient care may be compromised. Further research is needed to assess the longterm effects of changes on both residents and patients.

Research paper thumbnail of Evaluating the research performance of the Greek medical schools using bibliometrics

Research paper thumbnail of Commentary: occlusion of parallel/bridging stent-grafts in the treatment of complex aneurysms: a purely technical issue . . . Or not?

Journal of endovascular therapy : an official journal of the International Society of Endovascular Specialists, 2015

Research paper thumbnail of Risk Factors for Ipsilateral Reamputation in Patients with Diabetic Foot Lesions

The International Journal of Lower Extremity Wounds, 2009

This study aimed to examine the rates and risk factors for ipsilateral re-amputation in 121 patie... more This study aimed to examine the rates and risk factors for ipsilateral re-amputation in 121 patients with diabetic foot and prior amputation. Twenty-six (21.5%) patients required re-amputation during a mean follow-up of 18 months. Most re-amputations were performed within the first 6 months of the initial amputation. Re-amputation was more common among patients in whom the initial amputation had only affected one or two toes. Age (hazard ratio: 1.06) and heel lesions (hazard ratio: 2.69) were significantly associated with re-amputation. There is a high risk of re-amputation in the diabetic foot, especially within the first 6 months of the initial amputation, mainly due to poor selection of the original amputation level in an effort to save a greater part of the lower extremity. Patients 70 years and those with heel lesions are at greatest risk of re-amputation.

Research paper thumbnail of Wound Physicians: Lymphedema Is Not a Problem That Will Go Away if Ignored

The International Journal of Lower Extremity Wounds, 2012

Research paper thumbnail of Removal of Knotted Intravascular Devices. Case Report and Review of the Literature

European Journal of Vascular and Endovascular Surgery, 2002

Objective: to review published reports on knotted intravascular devices/catheters. Method: report... more Objective: to review published reports on knotted intravascular devices/catheters. Method: report of two cases and systematic review of the literature. Results: a total of 113 reported cases of knotted intravascular devices/catheters were located. Pulmonary artery catheters (Swan-Ganz) were responsible for more than two thirds of the total reported intravascular knots. In 62% (70/113) of the cases withdrawal of the knotted catheters was achieved successfully with different interventional radiological techniques, avoiding the need for surgical exploration. In 32% (36/113) of the patients surgical removal was favoured. Capture with one of the interventional techniques and pulling down the knot into an easily accessible vein to be removed through an open venotomy, was the most common surgical procedure. However, in five cases, an open cardiotomy was required. In seven cases the patient's condition was critical and precluded any surgical procedure, so the knotted catheter was left in situ. The mortality of this event was 8% (9/113). Conclusions: interventional radiological techniques have largely replaced open surgical removal. Knotted catheters may need to be surgically removed when (a) the knot is large in size with many loops, or (b) intracardiac fixing of the knot is encountered.

Research paper thumbnail of Surgical treatment of femoral artery infected false aneurysms in drug abusers

ANZ Journal of Surgery, 2005

Post-traumatic femoral artery infected false aneurysms (pfa-IFA) in drug abusers are very common ... more Post-traumatic femoral artery infected false aneurysms (pfa-IFA) in drug abusers are very common in modern societies, but their surgical management remains controversial. A review was undertaken of the English-language literature between 1967 and 2004 for relevant articles describing at least four cases of pfa-IFA in drug-addict populations. The available surgical treatment options are discussed. Recent surgical therapeutic reports favour aneurysm ligation and excision (Lig-Exc) and local debridement (Ld) with observation-selective (delayed) revascularization in cases where limb viability is threatened, or Lig-Exc and Ld alone without vascular reconstruction. The former method carries the risk of delayed decision on attempted extremity salvage (12.1% amputation rate), accepting early (13.5%) and late (7.5%) claudication rate, and although the latter method has much lower early and late amputation rates (5.7 and 6.3%, respectively), it results in a high percentage of claudication and disability (early, 54.4%; late, 44.3%). Immediate (routine) revascularization using either in situ or extra-anatomic bypass has also been associated with high complication rates. Even when it occurs through non-infected tissue planes, the risk of graft infection (early, 21.1%; late, 32.4%) is of great concern, and the possibility of sepsis (together with anastomotic dehiscence (14%) and even amputation) is high (early, 9.8%; late, 11.3%). Reversing the order of revascularization produces zero early complication rates, but long-term follow up reveals that 5.5% of patients have graft infection and 5.5% have had amputation. The follow up rates reported in the literature are poor (only 31.7% completed), and are also sometimes inaccurate. No surgical treatment for pfa-IFA has been proved to be safe in terms of the overall surgical complications. Longer follow-up periods are needed to provide accurate results.

Research paper thumbnail of Systematic Review of Off-the-Shelf or Physician-Modified Fenestrated and Branched Endografts

Journal of endovascular therapy : an official journal of the International Society of Endovascular Specialists, Jan 23, 2015

To determine the safety and efficacy of off-the-shelf fenestrated/branched grafts (OSFGs) and phy... more To determine the safety and efficacy of off-the-shelf fenestrated/branched grafts (OSFGs) and physician-modified stent-grafts (PMSGs) for the treatment of complex abdominal aortic aneurysms. A systematic search of the MEDLINE database via PubMed from January 2001 through March 2015 retrieved 23 relevant articles evaluating the clinical outcomes following the management of patients with pararenal or thoracoabdominal aortic aneurysms. The 15 articles on PMSGs and 8 on OSFGs contained data on 308 patients (mean age 72.93±2.89 years; 213 men). The safety endpoint was major adverse events; the efficacy outcome measure was clinical treatment success (aneurysm exclusion without type I/III endoleak, permanent paralysis, long-term dialysis, or unresolved major complications). Extracted outcome data were pooled and compared between groups; data are given as the pooled proportions and 95% confidence interval (CI). Clinical data are presented as the weighted mean. Of the 308 patients analyzed, ...

Research paper thumbnail of Preemptive open surgical vs. endovascular repair for juxta-anastomotic stenoses of autogenous AV fistulae: a meta-analysis

The Journal of Vascular Access, 2012

There is controversy about the best mode of preemptive repair of juxta-anastomotic stenoses in ra... more There is controversy about the best mode of preemptive repair of juxta-anastomotic stenoses in radial-cephalic arteriovenous fistula (AVFs). The aim of the present review was to compare the outcome of surgical vs. endovascular repair of those AVF stenoses. A systematic review and meta-analysis was performed for studies comparing the outcome of open surgical vs. endovascular preemptive repair of AVF stenoses located in the juxta-anastomotic region. A search was carried out in April 2015. The analyzed outcome measures were the primary patency at 12 and 18 months and the assisted primary patency at 24 months. In addition, assessment of the methodological quality of the included studies was carried out. Four non-randomized cohort studies (297 patients) were analyzed. A random effects model was used to pool the data. The pooled odds ratio (OR and 95% confidence intervals) for the primary patency at 12 and at 18 months was 0.42 (0.25-0.72) and 0.33 (0.2-0.56), respectively, showing statistically significant higher patency of the surgically repaired group. The pooled OR for the assisted primary patency at 24 months was 0.53 (0.28-0.98) also in favor of the surgically repaired group (plt;0.04). The available evidence, based on non-randomized cohort studies, suggests that surgery is the best way to treat &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;juxta-anastomotic&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; stenotic lesions in distal radial-cephalic AVFs, although angioplasty remains a valuable but less durable option in this location of the stenosis.

Research paper thumbnail of The shear stess profile of the pivotal fenestrated endograft at the level of the renal branches: A computational study for complex aortic aneurysms

Vascular, 2015

This study investigated the impact of the variant angulations on the values and distribution of w... more This study investigated the impact of the variant angulations on the values and distribution of wall shear stress on the renal branches and the mating vessels of a pivotal fenestrated design. An idealized endograft model of two renal branches was computationally reconstructed with variable angulations of the left renal branch. These ranged from the 1:30&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; to 3:30&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; o&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;clock position, corresponding from 45° to 105° with increments of 15°. A fluid-structure-interaction analysis was performed to estimate the wall shear stress. The proximal part of the renal branch preserved quite constant wall shear stress. The transition zone between its distal end and the renal artery showed the highest values compared to the proximal and middle segments, ranging from 8.9 to 12.4 Pa. The lowest stress values presented at 90° whereas the highest at 45°. The post-mating arterial segment showed constantly low stress values regardless of the pivotal branch angle (6.3 to 6.6 Pa). The 45° configuration showed a distribution of the highest stress posteriorly whereas the 105°-angulation anteriorly. The variant horizontal branch orientation influences the wall shear stress distribution across its length and affects its values only at its transition with the mating vessel. These findings and their potential association with adverse effects deserve further clinical validation.

Research paper thumbnail of Emergent conversion of the Ovation Stent Graft System to aortouniiliac modification via occlusion of a unilateral internal iliac artery with a stentgraft as a bailout solution

Vascular, 2015

Purpose: To present a case of inadvertent collapse of the contralateral limb gate caused by misor... more Purpose: To present a case of inadvertent collapse of the contralateral limb gate caused by misorientation during the deployment of the Ovation Abdominal Stent Graft System in a narrow aortic lumen and the bailout conversion to aortouniiliac modification, using a covered stent to exclude the orifice of the internal iliac artery (IIA). Technique description: Despite the repeated efforts from the femoral and brachial site, the collapsed/occluded contralateral limb gate could not be catheterized. In order to exclude successfully the orifice of the IIA, an oversized stentgraft was placed immediately at the common-to-external iliac artery (CIA-EIA) transition followed by peripheral ligation of the latter. The procedure was completed with crossover femorofemoral bypass. Conclusion: Occlusion the IIA orifice with an oversized stentgraft in the CIA-EIA transition can be considered as a safe, simple, fast, and efficient bailout maneuver, followed by EIA ligation and crossover bypass.

Research paper thumbnail of The effect of Ovation Stent-Graft System on aortic pulse wave velocity: preliminary report on three cases

Annals of Vascular Surgery, 2015

The Ovation Aortic Stent-Graft System is based on a pair of polymer-filled inflatable O-rings to ... more The Ovation Aortic Stent-Graft System is based on a pair of polymer-filled inflatable O-rings to achieve sealing at the infrarenal level. However, this O-rings inflation has been associated with restriction of flow lumen and regional stenosis up to ∼60%. Since the aortic pulse wave velocity (aPWV) is considered a valuable marker of aorta stiffening we investigated the influence of the O-rings induced aortic lumen stenosis on the aPWV during the early postoperative period in a sample of 3 patients. The internal cross-sectional area and the corresponding radius at the level immediately caudally to the renal arteries (Aupper and Rupper) and at the site of the inflated O-rings (Aint and Rint) was calculated from postoperative images of Computed tomography using dedicated software (3Mensio Medical Imaging B.V., Bilthoven, The Netherlands). Accordingly, the difference in the previously mentioned parameters between these areas was recorded. Noninvasive estimation of aPWV was conducted preoperatively and at 1-week and 1-month postoperatively with a brachial cuff-based automatic oscillometric device (Mobil-O-Graph; IEM, Stolberg, Germany). Aupper was 286, 385, and 286 mm(2) for the 3 patients with Aint being 116, 86 and 95 mm(2), corresponding to inflow stenosis of 60%, 75%, and 66%, respectively. Accordingly, the radius reduction of the lumen between Rupper and Rint was 35%, 50%, and 60%. aPWV was kept quite constant for all patients 1-week and 1-month postoperatively, ranging 13.2-13.7, 11.4-11.5, and 8.3-8.6 m/sec, respectively. The inflow restriction caused by the stiff, inflatable O-rings does not necessarily coincide with significant increase of aortic stiffness in the early postoperative period. Furthermore studies with more hemodynamic indices and longer follow-up are needed to delineate the impact of the Ovation&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s unique structural pattern on central hemodynamics.

Research paper thumbnail of Randomized Controlled Trial Comparing Primary and Staged Basilic Vein Transposition

Frontiers in Surgery, 2015

Objective: It is unclear if brachio-basilic vein fistula should be performed as a primary or stag... more Objective: It is unclear if brachio-basilic vein fistula should be performed as a primary or staged procedure, particularly for smaller basilic veins. Our aim was to report on a randomized controlled trial comparing these two techniques.

Research paper thumbnail of Reversal of deep vein reflux after successful stenting in a patient with venous hypertension after thigh access graft creation

Vascular and endovascular surgery

Presented here is a case of reversal of deep vein reflux after successful stenting in a patient w... more Presented here is a case of reversal of deep vein reflux after successful stenting in a patient with venous hypertension and valve incompetence after thigh angioaccess creation. The patient with exhausted upper-extremity access sites underwent a loop graft in the upper thigh. Six months later, the patient developed leg edema and significant femoral vein reflux on duplex ultrasound. Fistulography revealed an iliac vein stenosis, which was treated successfully with stenting. The edema and reflux on duplex promptly resolved. In similar cases, reflux may be a consequence of functional valve incompetence and can be reverted by timely treating the underlying stenosis.

Research paper thumbnail of Technical advances with newer aortic endografts provide additional support to withhold the early endovascular repair of small abdominal aortic aneurysms until it is really needed

Vascular and endovascular surgery, 2012

The idea of early endovascular aortic repair (EVAR) of "small" abdominal aortic aneurys... more The idea of early endovascular aortic repair (EVAR) of "small" abdominal aortic aneurysms (AAAs) has gained attention over "watchful waiting," mostly due to the concern for losing the anatomic suitability for endovascular repair over time. Generally, small AAAs have longer, smaller, less angulated necks, and less tortuous iliac arteries than larger ones. Though the borderline anatomic characteristics were assumed to be contraindications for older generation endografts, the modifications of modern devices seem promising to overcome those limitations, in order to treat the small AAAs when reaching the 5.5 cm threshold. Moreover, early endovascular intervention has been proven neither cost effective nor beneficial for the patients' quality of life. This article evaluates the technical progress that could overcome the difficulties of those small AAAs that present technically demanding anatomies, thus advocating endovascular intervention when they reach the diamet...

Research paper thumbnail of Troubleshooting techniques for the Endurant™ device in endovascular aortic aneurysm repair : cardiovascular topic

Cardiovascular Journal Of Africa, 2014

Endovascular aortic aneurysm repair with the Endurant™ stent-graft system has been shown to be sa... more Endovascular aortic aneurysm repair with the Endurant™ stent-graft system has been shown to be safe and effective in high-risk surgical patients with complex suprarenal and/or infrarenal abdominal aortic aneurysm anatomy. The wireformed M-shaped stent architecture and proximal springs with anchoring pins theoretically permit optimal sealing in shorter and more angulated proximal aneurysm necks even under off-label conditions. Nonetheless, extremely difficult anatomical situations and inherent graft system-related limitations must be anticipated. Herein, we describe our techniques to overcome the capture of the tip sleeve within the suprarenal bare-stent anchoring pins, other endograft segments, and native vessels.

Research paper thumbnail of Aneurysm formation and infection in AV prosthesis

The journal of vascular access, 2014

In contrast to autogenous arteriovenous (AV) fistulae where true aneurysms are the most frequent ... more In contrast to autogenous arteriovenous (AV) fistulae where true aneurysms are the most frequent type, aneurysms in prosthetic AV grafts are mostly false aneurysms and less frequently anastomotic ones. Indications for repair comprise false aneurysms exceeding twofold the graft diameter, those with rapid enlargement or with skin thinning or erosion, the ruptured, those causing pain or severely limiting the cannulable area and the infected ones. They can be managed either with conventional surgery or with endovascular techniques; However, conventional surgery represents the current standard treatment consisting of either aneurysm resection and interposition graft in situ or resection/exclusion and bypass via a new route to avoid a potentially contaminated area.

Research paper thumbnail of Safety issues in surgical and endovascular techniques to rescue failing or failed arteriovenous fistulas and arteriovenous grafts

Contributions to nephrology, 2015

A great variety of thrombotic and nonthrombotic events may complicate all types of vascular acces... more A great variety of thrombotic and nonthrombotic events may complicate all types of vascular access (VA) procedures. Thrombotic events are the most frequent complication, caused by stenoses in various locations, representing a common problem for arteriovenous fistulas (AVFs) and arteriovenous grafts (AVGs). Monitoring AVF with physical examination by trained physicians represents an accurate method for diagnosis of malfunction. AVF stenoses >50% in diameter should be treated either by surgical or endovascular means when accompanied with access malfunction. Aneurysms and infections represent the most frequent nonthrombotic VA complications. Access-related aneurysms do not represent per se an indication for intervention; however, anastomotic aneurysms and those with skin erosion should be repaired urgently to avoid rupture. Infections of AVFs are extremely rare, while AVG could be complicated either with postoperative infections attributable to the initial procedure with an early on...

Research paper thumbnail of What is the best training for vascular access surgery?

The journal of vascular access, Jan 16, 2015

Questions have been raised whether there is a lack of appropriate training in access creation and... more Questions have been raised whether there is a lack of appropriate training in access creation and maintenance, and if training juniors in arteriovenous (AV) fistulas may affect the outcome. A survey was undertaken to study "experts" opinion in access training using a closed questionnaire. The majority of "experts" consented that there is a lack of appropriate training in access creation and maintenance in a great extent, although they located the main deficit regarding access training in the preoperative planning and decision making.Regarding the second question, a literature search revealed only four studies, comparing the outcomes of AV fistulas created either by consultant surgeons or trainees. A meta-analysis performed revealed that 1-year patency rate was not statistically significant different among access procedures created either by consultants or trainees. Access surgery shares the same basic principles with vascular surgery and provides a valuable workl...

Research paper thumbnail of Factors affecting the lifespan of autologous and synthetic arteriovenous access routes for haemodialysis

The European journal of surgery = Acta chirurgica, 1996

To try and establish a consensus about the ideal secondary access for haemodialysis by assessing ... more To try and establish a consensus about the ideal secondary access for haemodialysis by assessing factors that affect the longevity of various access routes. Multicentre survey, by questionnaire. General hospital, Athens. All 1516 patients in the Athens area receiving chronic haemodialysis. Longevity of present and any previous access routes (n = 2323). Data including type of access, age, sex and the existence of diabetes, hypertension, hyperlipidaemia, or other systematic diseases were recorded. Some 1220 (80%) of the patients were using autologous access, 1049 (69%) arteriovenous (AV) fistulas at wrist and 171 (11%) at elbow. Variables were analysed using Cox's proportional hazard model. Age and female sex were significantly associated with failure of autogenous access (p < 0.001) although not affecting synthetic grafts. Autogenous fistula at the elbow was the only secondary access that was less likely to fail than the initial (baseline) fistula at the wrist. Among the vario...

Research paper thumbnail of Effects of limited work hours on surgical training

BACKGROUND: Legal mandates to reduce resident work hours have prompted changes in the structure o... more BACKGROUND: Legal mandates to reduce resident work hours have prompted changes in the structure of surgical training programs. Such changes have included modification of on-call schedules and the adoption of "night float" resident coverage. Little is known about the effects of these changes on surgical resident education and perceptions of quality of patient care. STUDY DESIGN: The surgical housestaff and faculty at a single institution completed a 21-point Likert survey. Subjects were asked to compare parameters of resident education, patient care, and resident quality of life before and after institution of a strict 80-hour work week resident training schedule. The number of hours worked per week before and after these changes were reported. American Board of Surgery In-Training Examination (ABSITE) scores were compared for the 2 years before and after implementation of this schedule. Total number of surgical cases performed by graduating chief residents were recorded and compared for the 3 years before and after the schedule changes. RESULTS: Resident work hours reduced significantly after schedule changes were implemented. A majority of surgical residents reported an improvement in quality of life, but residents and faculty perceived changes to have a negative impact on continuity of patient care. Mean ABSITE composite percentile scores significantly improved after the reduction of working hours. AB-SITE scores for junior residents improved significantly; no significant differences were noted in scores for senior residents. CONCLUSIONS: Reduction in resident work hours has salutary effects on perception of quality of life and basic education for surgical residents. These benefits may come at the expense of patient care, particularly continuity of care. This study did not directly assess patient outcomes but the perceptions of caregivers suggest that patient care may be compromised. Further research is needed to assess the longterm effects of changes on both residents and patients.

Research paper thumbnail of Evaluating the research performance of the Greek medical schools using bibliometrics

Research paper thumbnail of Commentary: occlusion of parallel/bridging stent-grafts in the treatment of complex aneurysms: a purely technical issue . . . Or not?

Journal of endovascular therapy : an official journal of the International Society of Endovascular Specialists, 2015

Research paper thumbnail of Risk Factors for Ipsilateral Reamputation in Patients with Diabetic Foot Lesions

The International Journal of Lower Extremity Wounds, 2009

This study aimed to examine the rates and risk factors for ipsilateral re-amputation in 121 patie... more This study aimed to examine the rates and risk factors for ipsilateral re-amputation in 121 patients with diabetic foot and prior amputation. Twenty-six (21.5%) patients required re-amputation during a mean follow-up of 18 months. Most re-amputations were performed within the first 6 months of the initial amputation. Re-amputation was more common among patients in whom the initial amputation had only affected one or two toes. Age (hazard ratio: 1.06) and heel lesions (hazard ratio: 2.69) were significantly associated with re-amputation. There is a high risk of re-amputation in the diabetic foot, especially within the first 6 months of the initial amputation, mainly due to poor selection of the original amputation level in an effort to save a greater part of the lower extremity. Patients 70 years and those with heel lesions are at greatest risk of re-amputation.

Research paper thumbnail of Wound Physicians: Lymphedema Is Not a Problem That Will Go Away if Ignored

The International Journal of Lower Extremity Wounds, 2012

Research paper thumbnail of Removal of Knotted Intravascular Devices. Case Report and Review of the Literature

European Journal of Vascular and Endovascular Surgery, 2002

Objective: to review published reports on knotted intravascular devices/catheters. Method: report... more Objective: to review published reports on knotted intravascular devices/catheters. Method: report of two cases and systematic review of the literature. Results: a total of 113 reported cases of knotted intravascular devices/catheters were located. Pulmonary artery catheters (Swan-Ganz) were responsible for more than two thirds of the total reported intravascular knots. In 62% (70/113) of the cases withdrawal of the knotted catheters was achieved successfully with different interventional radiological techniques, avoiding the need for surgical exploration. In 32% (36/113) of the patients surgical removal was favoured. Capture with one of the interventional techniques and pulling down the knot into an easily accessible vein to be removed through an open venotomy, was the most common surgical procedure. However, in five cases, an open cardiotomy was required. In seven cases the patient's condition was critical and precluded any surgical procedure, so the knotted catheter was left in situ. The mortality of this event was 8% (9/113). Conclusions: interventional radiological techniques have largely replaced open surgical removal. Knotted catheters may need to be surgically removed when (a) the knot is large in size with many loops, or (b) intracardiac fixing of the knot is encountered.

Research paper thumbnail of Surgical treatment of femoral artery infected false aneurysms in drug abusers

ANZ Journal of Surgery, 2005

Post-traumatic femoral artery infected false aneurysms (pfa-IFA) in drug abusers are very common ... more Post-traumatic femoral artery infected false aneurysms (pfa-IFA) in drug abusers are very common in modern societies, but their surgical management remains controversial. A review was undertaken of the English-language literature between 1967 and 2004 for relevant articles describing at least four cases of pfa-IFA in drug-addict populations. The available surgical treatment options are discussed. Recent surgical therapeutic reports favour aneurysm ligation and excision (Lig-Exc) and local debridement (Ld) with observation-selective (delayed) revascularization in cases where limb viability is threatened, or Lig-Exc and Ld alone without vascular reconstruction. The former method carries the risk of delayed decision on attempted extremity salvage (12.1% amputation rate), accepting early (13.5%) and late (7.5%) claudication rate, and although the latter method has much lower early and late amputation rates (5.7 and 6.3%, respectively), it results in a high percentage of claudication and disability (early, 54.4%; late, 44.3%). Immediate (routine) revascularization using either in situ or extra-anatomic bypass has also been associated with high complication rates. Even when it occurs through non-infected tissue planes, the risk of graft infection (early, 21.1%; late, 32.4%) is of great concern, and the possibility of sepsis (together with anastomotic dehiscence (14%) and even amputation) is high (early, 9.8%; late, 11.3%). Reversing the order of revascularization produces zero early complication rates, but long-term follow up reveals that 5.5% of patients have graft infection and 5.5% have had amputation. The follow up rates reported in the literature are poor (only 31.7% completed), and are also sometimes inaccurate. No surgical treatment for pfa-IFA has been proved to be safe in terms of the overall surgical complications. Longer follow-up periods are needed to provide accurate results.

Research paper thumbnail of Systematic Review of Off-the-Shelf or Physician-Modified Fenestrated and Branched Endografts

Journal of endovascular therapy : an official journal of the International Society of Endovascular Specialists, Jan 23, 2015

To determine the safety and efficacy of off-the-shelf fenestrated/branched grafts (OSFGs) and phy... more To determine the safety and efficacy of off-the-shelf fenestrated/branched grafts (OSFGs) and physician-modified stent-grafts (PMSGs) for the treatment of complex abdominal aortic aneurysms. A systematic search of the MEDLINE database via PubMed from January 2001 through March 2015 retrieved 23 relevant articles evaluating the clinical outcomes following the management of patients with pararenal or thoracoabdominal aortic aneurysms. The 15 articles on PMSGs and 8 on OSFGs contained data on 308 patients (mean age 72.93±2.89 years; 213 men). The safety endpoint was major adverse events; the efficacy outcome measure was clinical treatment success (aneurysm exclusion without type I/III endoleak, permanent paralysis, long-term dialysis, or unresolved major complications). Extracted outcome data were pooled and compared between groups; data are given as the pooled proportions and 95% confidence interval (CI). Clinical data are presented as the weighted mean. Of the 308 patients analyzed, ...

Research paper thumbnail of Preemptive open surgical vs. endovascular repair for juxta-anastomotic stenoses of autogenous AV fistulae: a meta-analysis

The Journal of Vascular Access, 2012

There is controversy about the best mode of preemptive repair of juxta-anastomotic stenoses in ra... more There is controversy about the best mode of preemptive repair of juxta-anastomotic stenoses in radial-cephalic arteriovenous fistula (AVFs). The aim of the present review was to compare the outcome of surgical vs. endovascular repair of those AVF stenoses. A systematic review and meta-analysis was performed for studies comparing the outcome of open surgical vs. endovascular preemptive repair of AVF stenoses located in the juxta-anastomotic region. A search was carried out in April 2015. The analyzed outcome measures were the primary patency at 12 and 18 months and the assisted primary patency at 24 months. In addition, assessment of the methodological quality of the included studies was carried out. Four non-randomized cohort studies (297 patients) were analyzed. A random effects model was used to pool the data. The pooled odds ratio (OR and 95% confidence intervals) for the primary patency at 12 and at 18 months was 0.42 (0.25-0.72) and 0.33 (0.2-0.56), respectively, showing statistically significant higher patency of the surgically repaired group. The pooled OR for the assisted primary patency at 24 months was 0.53 (0.28-0.98) also in favor of the surgically repaired group (plt;0.04). The available evidence, based on non-randomized cohort studies, suggests that surgery is the best way to treat &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;juxta-anastomotic&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; stenotic lesions in distal radial-cephalic AVFs, although angioplasty remains a valuable but less durable option in this location of the stenosis.

Research paper thumbnail of The shear stess profile of the pivotal fenestrated endograft at the level of the renal branches: A computational study for complex aortic aneurysms

Vascular, 2015

This study investigated the impact of the variant angulations on the values and distribution of w... more This study investigated the impact of the variant angulations on the values and distribution of wall shear stress on the renal branches and the mating vessels of a pivotal fenestrated design. An idealized endograft model of two renal branches was computationally reconstructed with variable angulations of the left renal branch. These ranged from the 1:30&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; to 3:30&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; o&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;clock position, corresponding from 45° to 105° with increments of 15°. A fluid-structure-interaction analysis was performed to estimate the wall shear stress. The proximal part of the renal branch preserved quite constant wall shear stress. The transition zone between its distal end and the renal artery showed the highest values compared to the proximal and middle segments, ranging from 8.9 to 12.4 Pa. The lowest stress values presented at 90° whereas the highest at 45°. The post-mating arterial segment showed constantly low stress values regardless of the pivotal branch angle (6.3 to 6.6 Pa). The 45° configuration showed a distribution of the highest stress posteriorly whereas the 105°-angulation anteriorly. The variant horizontal branch orientation influences the wall shear stress distribution across its length and affects its values only at its transition with the mating vessel. These findings and their potential association with adverse effects deserve further clinical validation.

Research paper thumbnail of Emergent conversion of the Ovation Stent Graft System to aortouniiliac modification via occlusion of a unilateral internal iliac artery with a stentgraft as a bailout solution

Vascular, 2015

Purpose: To present a case of inadvertent collapse of the contralateral limb gate caused by misor... more Purpose: To present a case of inadvertent collapse of the contralateral limb gate caused by misorientation during the deployment of the Ovation Abdominal Stent Graft System in a narrow aortic lumen and the bailout conversion to aortouniiliac modification, using a covered stent to exclude the orifice of the internal iliac artery (IIA). Technique description: Despite the repeated efforts from the femoral and brachial site, the collapsed/occluded contralateral limb gate could not be catheterized. In order to exclude successfully the orifice of the IIA, an oversized stentgraft was placed immediately at the common-to-external iliac artery (CIA-EIA) transition followed by peripheral ligation of the latter. The procedure was completed with crossover femorofemoral bypass. Conclusion: Occlusion the IIA orifice with an oversized stentgraft in the CIA-EIA transition can be considered as a safe, simple, fast, and efficient bailout maneuver, followed by EIA ligation and crossover bypass.

Research paper thumbnail of The effect of Ovation Stent-Graft System on aortic pulse wave velocity: preliminary report on three cases

Annals of Vascular Surgery, 2015

The Ovation Aortic Stent-Graft System is based on a pair of polymer-filled inflatable O-rings to ... more The Ovation Aortic Stent-Graft System is based on a pair of polymer-filled inflatable O-rings to achieve sealing at the infrarenal level. However, this O-rings inflation has been associated with restriction of flow lumen and regional stenosis up to ∼60%. Since the aortic pulse wave velocity (aPWV) is considered a valuable marker of aorta stiffening we investigated the influence of the O-rings induced aortic lumen stenosis on the aPWV during the early postoperative period in a sample of 3 patients. The internal cross-sectional area and the corresponding radius at the level immediately caudally to the renal arteries (Aupper and Rupper) and at the site of the inflated O-rings (Aint and Rint) was calculated from postoperative images of Computed tomography using dedicated software (3Mensio Medical Imaging B.V., Bilthoven, The Netherlands). Accordingly, the difference in the previously mentioned parameters between these areas was recorded. Noninvasive estimation of aPWV was conducted preoperatively and at 1-week and 1-month postoperatively with a brachial cuff-based automatic oscillometric device (Mobil-O-Graph; IEM, Stolberg, Germany). Aupper was 286, 385, and 286 mm(2) for the 3 patients with Aint being 116, 86 and 95 mm(2), corresponding to inflow stenosis of 60%, 75%, and 66%, respectively. Accordingly, the radius reduction of the lumen between Rupper and Rint was 35%, 50%, and 60%. aPWV was kept quite constant for all patients 1-week and 1-month postoperatively, ranging 13.2-13.7, 11.4-11.5, and 8.3-8.6 m/sec, respectively. The inflow restriction caused by the stiff, inflatable O-rings does not necessarily coincide with significant increase of aortic stiffness in the early postoperative period. Furthermore studies with more hemodynamic indices and longer follow-up are needed to delineate the impact of the Ovation&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s unique structural pattern on central hemodynamics.

Research paper thumbnail of Randomized Controlled Trial Comparing Primary and Staged Basilic Vein Transposition

Frontiers in Surgery, 2015

Objective: It is unclear if brachio-basilic vein fistula should be performed as a primary or stag... more Objective: It is unclear if brachio-basilic vein fistula should be performed as a primary or staged procedure, particularly for smaller basilic veins. Our aim was to report on a randomized controlled trial comparing these two techniques.

Research paper thumbnail of Reversal of deep vein reflux after successful stenting in a patient with venous hypertension after thigh access graft creation

Vascular and endovascular surgery

Presented here is a case of reversal of deep vein reflux after successful stenting in a patient w... more Presented here is a case of reversal of deep vein reflux after successful stenting in a patient with venous hypertension and valve incompetence after thigh angioaccess creation. The patient with exhausted upper-extremity access sites underwent a loop graft in the upper thigh. Six months later, the patient developed leg edema and significant femoral vein reflux on duplex ultrasound. Fistulography revealed an iliac vein stenosis, which was treated successfully with stenting. The edema and reflux on duplex promptly resolved. In similar cases, reflux may be a consequence of functional valve incompetence and can be reverted by timely treating the underlying stenosis.

Research paper thumbnail of Technical advances with newer aortic endografts provide additional support to withhold the early endovascular repair of small abdominal aortic aneurysms until it is really needed

Vascular and endovascular surgery, 2012

The idea of early endovascular aortic repair (EVAR) of "small" abdominal aortic aneurys... more The idea of early endovascular aortic repair (EVAR) of "small" abdominal aortic aneurysms (AAAs) has gained attention over "watchful waiting," mostly due to the concern for losing the anatomic suitability for endovascular repair over time. Generally, small AAAs have longer, smaller, less angulated necks, and less tortuous iliac arteries than larger ones. Though the borderline anatomic characteristics were assumed to be contraindications for older generation endografts, the modifications of modern devices seem promising to overcome those limitations, in order to treat the small AAAs when reaching the 5.5 cm threshold. Moreover, early endovascular intervention has been proven neither cost effective nor beneficial for the patients' quality of life. This article evaluates the technical progress that could overcome the difficulties of those small AAAs that present technically demanding anatomies, thus advocating endovascular intervention when they reach the diamet...

Research paper thumbnail of Troubleshooting techniques for the Endurant™ device in endovascular aortic aneurysm repair : cardiovascular topic

Cardiovascular Journal Of Africa, 2014

Endovascular aortic aneurysm repair with the Endurant™ stent-graft system has been shown to be sa... more Endovascular aortic aneurysm repair with the Endurant™ stent-graft system has been shown to be safe and effective in high-risk surgical patients with complex suprarenal and/or infrarenal abdominal aortic aneurysm anatomy. The wireformed M-shaped stent architecture and proximal springs with anchoring pins theoretically permit optimal sealing in shorter and more angulated proximal aneurysm necks even under off-label conditions. Nonetheless, extremely difficult anatomical situations and inherent graft system-related limitations must be anticipated. Herein, we describe our techniques to overcome the capture of the tip sleeve within the suprarenal bare-stent anchoring pins, other endograft segments, and native vessels.

Research paper thumbnail of Aneurysm formation and infection in AV prosthesis

The journal of vascular access, 2014

In contrast to autogenous arteriovenous (AV) fistulae where true aneurysms are the most frequent ... more In contrast to autogenous arteriovenous (AV) fistulae where true aneurysms are the most frequent type, aneurysms in prosthetic AV grafts are mostly false aneurysms and less frequently anastomotic ones. Indications for repair comprise false aneurysms exceeding twofold the graft diameter, those with rapid enlargement or with skin thinning or erosion, the ruptured, those causing pain or severely limiting the cannulable area and the infected ones. They can be managed either with conventional surgery or with endovascular techniques; However, conventional surgery represents the current standard treatment consisting of either aneurysm resection and interposition graft in situ or resection/exclusion and bypass via a new route to avoid a potentially contaminated area.

Research paper thumbnail of Safety issues in surgical and endovascular techniques to rescue failing or failed arteriovenous fistulas and arteriovenous grafts

Contributions to nephrology, 2015

A great variety of thrombotic and nonthrombotic events may complicate all types of vascular acces... more A great variety of thrombotic and nonthrombotic events may complicate all types of vascular access (VA) procedures. Thrombotic events are the most frequent complication, caused by stenoses in various locations, representing a common problem for arteriovenous fistulas (AVFs) and arteriovenous grafts (AVGs). Monitoring AVF with physical examination by trained physicians represents an accurate method for diagnosis of malfunction. AVF stenoses >50% in diameter should be treated either by surgical or endovascular means when accompanied with access malfunction. Aneurysms and infections represent the most frequent nonthrombotic VA complications. Access-related aneurysms do not represent per se an indication for intervention; however, anastomotic aneurysms and those with skin erosion should be repaired urgently to avoid rupture. Infections of AVFs are extremely rare, while AVG could be complicated either with postoperative infections attributable to the initial procedure with an early on...

Research paper thumbnail of What is the best training for vascular access surgery?

The journal of vascular access, Jan 16, 2015

Questions have been raised whether there is a lack of appropriate training in access creation and... more Questions have been raised whether there is a lack of appropriate training in access creation and maintenance, and if training juniors in arteriovenous (AV) fistulas may affect the outcome. A survey was undertaken to study "experts" opinion in access training using a closed questionnaire. The majority of "experts" consented that there is a lack of appropriate training in access creation and maintenance in a great extent, although they located the main deficit regarding access training in the preoperative planning and decision making.Regarding the second question, a literature search revealed only four studies, comparing the outcomes of AV fistulas created either by consultant surgeons or trainees. A meta-analysis performed revealed that 1-year patency rate was not statistically significant different among access procedures created either by consultants or trainees. Access surgery shares the same basic principles with vascular surgery and provides a valuable workl...