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D M Shah

Publications and source records attributed to D M Shah.

At least 37 records · Page 2Linked to original sources
PubMed2000

Use of shunts with eversion carotid endarterectomy.

PURPOSE: The purpose of this study was to examine the utility of carotid shunting in the context of eversion endarterectomy. A comparison of patients who underwent carotid endarterectomy by eversion with and without shunts was performed. METHODS: Over a 5-year period, 2724 eversion carotid endarterectomies were performed. In most of these operations patients were under cervical block anesthesia. A shunt was used in 112 eversion endarterectomies (4.1%). Cervical block anesthesia was used in 103 patients (92.0%), general anesthesia was used in 5 patients (4.5%), and 4 patients (3.6%) were converted from cervical block to general anesthesia intraoperatively. The indications for shunting were neurologic deterioration in 99 patients (88.4%) who were under cervical block anesthesia, procedures performed in neurologically unstable or otherwise compromised patients who were under general anesthesia, and the operator's discretion in the remaining eight patients. RESULTS: There was a combined stroke/death rate of 2.7% in the shunt group. These three cases included one death from myocardial infarction and one delayed death due to intracerebral hemorrhage after discharge. Shunt insertion was unrelated to the negative outcome in these two cases. One perioperative major stroke in the shunt group was identified. Follow-up averaged 12.3 months (range, 1-53 months). CONCLUSION: Carotid shunts can be used effectively in the context of eversion endarterectomy. Shunt insertion is not associated with an increased stroke/death rate in these patients.

Aged↗
PubMed2000

Reproductive tissue renin gene expression in preeclampsia.

OBJECTIVE: Using an analogy with renin gene overexpression, low-renin hypertension animal models, we wished to test the hypothesis that renin gene expression is increased in decidua basalis in human gestation with preeclampsia. METHODS: Human placentas were obtained immediately after delivery from 11 control (C) and 11 preeclamptics (PE). Tissue samples were microdissected and renin gene expression in decidua basalis (DB), chorionic villi (CV), and decidua vera (DV) was measured using dot-blot hybridization. RESULTS: Overall renin gene expression is highest in decidua basalis (mean +/- SEM, 2.66 +/- 0.69 densitometry area units) compared to chorionic villi (mean +/- SEM, 1.85 +/- 0.5) or compared to decidua vera (mean +/- SEM, 1.63 +/- 0.9) (both t-tests p = 0.001 two-tailed and analysis of variance p = 0.0001). Renin gene expression in DB and in CV was similar in both preeclamptic and normal pregnancies (DB mean +/- SEM C 2.79 +/- 0.96 versus PE 2.54 +/- 1.04, and CV mean +/- SEM C 2.11 +/- 0.91 versus PE, 1.59 +/- 0. 44). Renin gene expression in DV was approximately threefold higher in tissues from preeclamptics compared to control (mean +/- SEM PE 2. 44 +/- 1.76 versus C 0.82 +/- 0.42). Using the median value of 0.5 units for DV as cutoff, the preeclamptics displayed higher renin gene expression (chi square p = 0.033, two tailed). CONCLUSION: Our data suggest that renin gene expression is increased in preeclampsia in decidua vera. This may explain previously reported increased renin secretion in uterine circulation in preeclampsia.

Adult↗
PubMed2000

Carotid endarterectomy using the eversion technique.

Carotid endarterectomy by the eversion technique allows for all of the benefits of conventional endarterectomy but obviates the need for a distal suture line on the smaller internal carotid artery, and thus batching. Carotid artery reanastomosis onto the bifurcation can be quickly and simply performed with almost no risk of closure-related restenosis, given the anastomosis is on the larger of 2 arteries. In our experience of over 3,000 eversion carotid artery endarterectomies, the restenosis rate has been less than 1% judged by rigorous duplex follow-up. In this article, the technique and utility of eversion carotid endarterectomy is discussed.

Carotid Stenosis↗
PubMed1999

Combined use of iliac artery angioplasty and infrainguinal revascularization for treatment of multilevel atherosclerotic disease.

The purpose of this report is to review our recent experience with the combined use of iliac artery angioplasty and infrainguinal surgical revascularization for the treatment of multilevel atherosclerotic disease. A retrospective review of all patients with multilevel atherosclerotic disease who were treated with both iliac artery angioplasty and infrainguinal bypass surgery during a 4-year period was performed. The medical records and preoperative arteriograms of all patients were reviewed for demographic information, radiologic findings, and postoperative follow-up data. Ninety-three limbs in 87 patients were studied. There were 57 male and 30 female patients with an average age of 67.2 years (range: 38-90). We concluded that the combined use of iliac artery angioplasty and infrainguinal surgical revascularization is an effective and durable means of treating multilevel atherosclerotic disease.

Aged↗
PubMed1999

The incidence, natural history, and outcome of secondary intervention for persistent collateral flow in the excluded abdominal aortic aneurysm.

OBJECTIVE: The goal of abdominal aortic aneurysm (AAA) repair is the prevention of rupture. Exclusion of the infrarenal AAA by means of operation or endovascular graft placement is an alternative therapy to achieve this goal. However, thrombosis of the excluded aneurysm sac does not always occur and further intervention may be needed. This study examines the efficacy of available screening methods to detect the persistence of aneurysm sac flow and the outcome of secondary procedures to treat this problem. METHODS: During the past 14 years, 1218 patients have undergone operative retroperitoneal exclusion of AAA. To date, 48 patients have been found to have persistent flow in the excluded AAA sac with duplex scanning. Twenty-seven patients underwent surgical intervention, and seven of these procedures were performed for rupture. Six patients have undergone treatment with interventional techniques (four successfully). The patients were evaluated for preoperative angiographic, anatomic, and comorbid factors that may have predisposed them to failed exclusion. Also, perioperative morbidity and mortality, estimated blood loss, and survival were assessed in the patients who required surgical treatment. RESULTS: There were no perioperative parameters that correlated with postoperative persistent flow in the excluded AAA sac. The mean time to secondary intervention was 51 months (range, 2 to 113 months). Two patients had false-negative computed tomographic angiogram results, eight patients had false-negative angiogram results, and six patients had duplex scan examinations that had initially negative results that were then positive for flow in sac. Reoperation had a 7.4% mortality rate (two deaths) and a median blood loss of 2600 mL, as compared with 500 mL for primary procedures. CONCLUSION: Secondary operations for patent excluded aortic aneurysm sacs have higher mortality and intraoperative blood loss rates than do primary procedures for AAA repair. The localization of branch leaks with computerized tomographic angiography, angiography, and duplex scanning were imprecise, and better methods are needed to adequately diagnose patent sacs. Expansion of AAA sac may be the only reliable factor.

Adult↗
PubMed1999

Infrainguinal arterial reconstruction for claudication: is it worth the risk? An analysis of 409 procedures.

PURPOSE: Infrainguinal reconstruction traditionally has been reserved for patients with limb-threatening ischemia. Surgery for debilitating claudication, however, has been discouraged as a result of the perceived fear of bypass graft failure, limb loss, and significant perioperative complications that may be worse than the natural history of the disease. In this study, the results of infrainguinal reconstructions for claudication performed during the past 10 years were evaluated for bypass graft patency, limb loss, and long-term survival rates. METHODS: Data were collected and reviewed from the vascular registry, the office charts, and the hospital records for patients who underwent infrainguinal bypass grafting for claudication. RESULTS: From 1987 to 1997, 409 infrainguinal reconstructions were performed for claudication (9% of all infrainguinal reconstructions in our unit). The patient population had the following demographics: 73% men, 28% with diabetes, 54% smokers, and an average age of 64 years (range, 24 to 91 years). Inflow was from the following arteries: iliac artery/graft, 10%; common femoral artery, 52%; superficial femoral artery, 19%; profunda femoris artery, 16%; and popliteal artery, 2%. The outflow vessels were the following arteries: 165 above-knee popliteal arteries (40%), 150 below-knee popliteal arteries (37%), and 94 tibial vessels (23%). The operative mortality rate was 0%, and one limb was lost in the series from distal embolization. The primary patency rates were 62%, 77%, and 86% for above-knee popliteal artery, below-knee popliteal artery, and tibial vessel reconstructions at 4 years, and the secondary patency rates were 64%, 81%, and 90%, respectively. Cumulative patient survival rates were 93% and 80% at 4 and 6 years as compared with 65% and 52%, respectively, for infrainguinal reconstructions performed for limb salvage. CONCLUSION: Infrainguinal arterial reconstruction for disabling claudication is a safe and durable procedure in selected patients. These data indicate that concern for limb loss, death, and limited life span of the patients with this disease may not be warranted.

Adult↗
PubMed1999

The use of low-dose heparin is safe in carotid endarterectomy and avoids the use of protamine sulfate.

Controversy exists concerning the appropriate dose of heparin needed during carotid endarterectomy. Use of high-dose heparin (100 U/kg) during carotid endarterectomy may require the use of protamine to minimize perioperative bleeding complications. At the authors' institution the use of 30 U/kg heparin for arterial reconstruction has obviated the need for protamine. A retrospective study of carotid endarterectomies performed was undertaken. Patients undergoing combined procedures with carotid endarterectomy were excluded. A total of 420 carotid endarterectomies were performed in 330 patients. All received 3000 U of heparin or less during carotid endarterectomy. Non-fatal stroke and transient neurological deficits occurred in 0.48% and 1.9%, respectively. Mortality was 0.9%. Wounds were dry in 97%, swollen in 2.5% and bloody in 0.5%. No patient received protamine. Two patients were returned to the operating room for re-exploration because of hematoma. In conclusion, the use of protamine may be safely avoided with 30 U/kg heparin, and give acceptable stroke- and minimal complication rates.

Anticoagulants↗
PubMed1999

Outcome after distal vascular reconstruction in women.

Although women are less likely to develop symptomatic atherosclerosis, little data exists on the long-term outcome of women undergoing infrainguinal arterial reconstructions. This study analyzes the operative mortality rate, complications, and the short-term and long-term results after these procedures in both men and women who had symptomatic vascular disease. From 1984 to 1997, 3956 infrainguinal arterial reconstructions were performed at Albany Medical Center. A total of 2474 (62.54%) reconstructions were performed in men and 1482 (37.46%) in women. The mean ages were 67 years for men and 71 years for women. Forty-three percent of the men were smokers compared with 26% of the women. Diabetes was present in 51% of the men and 55% of the women. Claudication was the indication for bypass in 298 (12.05%) men and 110 (7.42%) women. Limb salvage occurred in 2176 (87.95%) men and 1372 (92.58%) women. Perioperative 30-day patency rates were 96.66% in men and 96.50% in women. Primary patency rates at 1, 3, 5, and 10 years were compared; no significant difference existed between men and women. Secondary patency also was similar in both men and women. These results indicate that women requiring arterial reconstruction for infrainguinal occlusive disease had short-term and long-term graft patency results that were comparable with the results of men.

Aged↗
PubMed1999

Outcome of renal artery reconstruction: analysis of 687 procedures.

OBJECTIVE: To evaluate the short- and long-term results of surgical reconstruction of the renal arteries, the authors review their experience with more than 600 reconstructions performed over a 12-year period. SUMMARY BACKGROUND DATA: Reconstruction of the renal arteries, whether for primary renal indications or concomitantly with aortic reconstruction, has evolved over the past 40 years. There is concern that renal artery reconstructions carry significant rates of mortality and morbidity and may fare poorly compared with less-invasive procedures. METHODS: From 1986 to 1998, 687 renal artery reconstructions were performed in 568 patients. Of these, 105 patients had simultaneous bilateral renal artery reconstructions. Fifty-six percent of the patients were male; 11% had diabetes; 35% admitted to smoking at the time of surgery. Mean age was 67 (range, 1 to 92). One hundred fifty-six (23%) were primary procedures and the remainder were adjunctive procedures with aortic reconstructions; 406 were abdominal aortic aneurysms and 125 were aortoiliac occlusive disease. Five hundred procedures were bypasses, 108 were endarterectomies, 72 were reimplantation, and 7 were patch angioplasties. There were 31 surgical deaths (elective and emergent) in the entire group for a mortality rate of 5.5%. Predictors of increased risk of death were patients with aortoiliac occlusive disease and patients undergoing bilateral simultaneous renal artery revascularization. Cause of death was primarily cardiac. Other nonfatal complications included bleeding (nine patients) and wound infection (three patients). There were 9 immediate occlusions (1.3%) and 10 late occlusions (1.5%). Thirty-three patients (4.8%) had temporary worsening of their renal function after surgery. CONCLUSION: Renal artery revascularization is a safe and durable procedure. It can be performed in selected patients for primary renovascular pathology. It can also be an adjunct to aortic reconstruction with acceptable mortality and morbidity rates.

Adolescent↗
PubMed1998

Combined carotid endarterectomy and coronary artery bypass grafting does not increase the risk of perioperative stroke.

Patients who present for coronary artery bypass grafting with hemodynamically significant carotid artery lesions pose a difficult problem for both the cardiac and vascular surgeons. There is no consensus as to the proper management of these patients despite numerous studies. Prospective collection of data was performed in patients undergoing combined carotid endarterectomy and coronary artery bypass grafting's from April 1980 to November 1996. A total of 470 simultaneous carotid endarterectomy's and coronary artery bypass grafting's were performed in 420 patients. The average age of the patient was 69 years, with 62% being male, 15% being diabetic and 38% being smokers. Sixty (13%) presented with Transient ischemic attacks, 22 (5%) presented with amaurosis fugax, 16 (3.4%) presented with a prior history of stroke and 372 (70%) were asymptomatic. Operative mortality was 2.4% or 10 patients; 90% of those patients died from cardiac complications postoperatively and one patient died of a stroke. Permanent neurological deficits occurred in five (1%) of the patients, and six (1.7%) of the patients had a transient neurological deficit that improved prior to discharge. In conclusion, in our experience simultaneous carotid endarterectomy with coronary artery bypass grafting can be performed with an acceptable mortality and morbidity and does not appear to put the patient at a higher risk than when either procedure is performed alone.

Aged↗
PubMed1998

Carotid endarterectomy by eversion technique: its safety and durability.

SUMMARY BACKGROUND DATA: The outcome of standard longitudinal carotid endarterectomy (CEA) can be measured by preservation of neurologic function with a low incidence of restenosis. Closure of the internal carotid arteriotomy with or without a patch may predispose to restenosis. Alternatively, transection of the internal carotid artery at the bulb with eversion endarterectomy allows expeditious removal of the plaque and direct visualization of the endpoint. Because the proximal internal carotid artery is anastomosed to the common carotid artery, this obviates the need for patch closure. The authors report their results with this technique in more than 2200 procedures. METHODS: From May 1993 to March 1998, 1855 patients underwent 2249 CEAs using the eversion technique. During the same period, 410 patients had 474 CEAs by standard technique. Three hundred fifteen procedures in the eversion group and 65 procedures in the standard group were combined CEA and coronary artery bypass grafts. Most solo CEAs (97%) were performed in awake patients using regional anesthesia. Shunts were used on demand in 6% of CEAs. RESULTS: The operative mortality rate was 1.02% (16/1575) in the solo eversion group and 2.2% (9/410) in the standard group. There were 18 permanent neurologic deficits (0.8%) in the eversion group and 11 (2.3%) in the standard group. Transient neurologic deficits occurred in 20 patients (0.9%) in the eversion group and 13 patients (2.7%) in the standard group. Of the 1855 patients, 1786 (96%) presented for duplex ultrasound follow-up. There were seven (0.3%) stenoses greater than 60% in the eversion group versus five (1.1%) in the standard group. CONCLUSIONS: Eversion CEA can be performed safely with a low rate of stroke and death and a minimal restenosis rate in short- and long-term follow-up.

Adult↗
PubMed1997

The performance of femoropopliteal bypasses using polytetrafluoroethylene above the knee versus autogenous vein below the knee.

BACKGROUND: Controversy exists as to the choice of conduit for the treatment of superficial femoral artery occlusive disease, particularly when a patent above-knee popliteal artery exists. Some surgeons advocate the preferential use of polytetrafluoroethylene (PTFE), whereas others favor the use of autogenous vein. This report compares our experience with above-knee femoropopliteal bypass with PTFE versus below-knee femoropopliteal bypass with autogenous vein. METHODS: This study covers a 15-year period extending from 1982 to 1996 during which 1,313 arterial reconstructions were performed for superficial femoral and/or proximal popliteal arterial disease. Four hundred and thirty-eight procedures were performed to the above-knee popliteal artery using PTFE, and 875 procedures were performed to the below-knee popliteal artery using autogenous vein. The indication for surgery was limb salvage in 77% of patients in the PTFE group and 88% of patients in the vein group. RESULTS: The 1-, 3-, and 5-year cumulative life table primary patency rates for the PTFE group were 74%, 56%, and 50%, respectively. The primary patency rates for the vein bypass group were 83%, 75%, and 67%, respectively (P < 0.01). The 5-year cumulative limb salvage rates were 91% and 95% for the PTFE and vein groups, respectively (P = NS). CONCLUSIONS: In this series, below-knee femoropopliteal venous reconstructions have superior patency rates compared with above-knee femoropopliteal PTFE reconstructions. Venous reconstruction for femoropopliteal occlusive disease gives the optimal long-term result. Prosthetic reconstruction should be considered for patients with limited venous conduit or decreased life expectancy.

Adult↗
PubMed1997

Timing of carotid endarterectomy in patients with recent stroke.

BACKGROUND: There is little objective data to support the conventional wisdom of waiting 4 to 6 weeks after stroke to improve surgical outcome of subsequent carotid endarterectomy (CEA). We have aggressively pursued CEA in patients after recent stroke; in this study we report our results. METHODS: We performed 215 CEA procedures in 200 patients who presented with an indication of stroke within 6 months of CEA. Cervical block anesthesia was used 193 cases. The rest were performed with the patient under general anesthesia. RESULTS: Perioperative stroke rate was 1.4% (3/215), and operative mortality was 2% (4/200) (stroke mortality = 3.4%). There were four early occlusions. Shunts were used in 13.9%, patch closure in 8.4%, and eversion endarterectomy in 48% of cases. There was no correlation between timing of surgery, extent of infarct on computed tomography/magnetic resonance imaging, and postoperative neurologic complications with the occurrence of postoperative stroke (p = NS). During the same period, 1,922 patients underwent CEA for indications other than stroke, with a perioperative stroke rate and mortality rate of 1.1%. CONCLUSIONS: Selected patients presenting with a history of stroke and significant carotid artery disease can safely undergo early CEA with a mortality and morbidity comparable to patients undergoing CEA for other indications.

Carotid Stenosis↗
PubMed1997

A prospective randomized study comparing exclusion technique and endoaneurysmorrhaphy for treatment of infrarenal aortic aneurysm.

PURPOSE: The retroperitoneal approach used in aortic replacement for infrarenal aortic aneurysm has become an important part of the vascular surgeon's armamentarium. Use of the exclusion and bypass technique, however, remains controversial. Although benefits may include reduced blood loss, less operative dissection, and a smoother intraoperative and postoperative course, critics of this technique have alluded to potential drawbacks. In this study the results of the exclusion technique and open endoaneurysmorrhaphy for surgical treatment of abdominal aortic aneurysm were compared. METHODS: One hundred patients were randomized to either exclusion (EXC) or open endoaneurysmorrhaphy (OP) procedures. A posterolateral left retroperitoneal approach was used in all patients. During surgery, autotransfusion devices were used when needed. Doppler flow and pressures in the excluded aneurysm sac were determined during surgery in EXC to evaluate the completeness of the exclusion. RESULTS: Patient demographics were similar between the two groups. The mean age was 70 years (range, 53 to 89 years). The operative mortality rates were 0% and 1.9% (1 of 51) in the EXC and OP groups, respectively. Nonfatal postoperative complications occurred in 10.2% (5 of 49) of the EXC group and in 23.5% (12 of 51) of the OP group (p < 0.05). Aneurysm sacs were opened in two EXC procedures. Blood loss (mean +/- SD) was 703 +/- 570 ml in the EXC group and 1031 +/- 703 ml in the OP group (p < or = 0.01). The intensive care unit stay (mean +/- SD) was 1.9 +/- 1.2 days in the EXC group and 3.2 +/- 6.9 days in the OP group (p = NS). The hospital stay (mean +/- SD) was 9.8 +/- 5.8 days and 12.1 +/- 17 days in the EXC and OP groups, respectively (p = NS). There has been persistent flow in the excluded sac in two patients, with sac enlargement in one of these patients on postoperative follow-up by duplex scan or clinical examination. CONCLUSION: The exclusion and bypass technique for repair of infrarenal aortic aneurysm appeared to be an acceptable technique and was associated with less operative blood loss and fewer postoperative complications than those of open aortic endoaneurysmorrhaphy. Exclusion bypass may contribute to a smoother perioperative course and postoperative treatment of these patients.

Aged↗
PubMed1997

Alternative approach for management of infected aortic grafts.

PURPOSE: Prosthetic infection after aortic reconstructive surgery historically has been treated with extraanatomical bypass, graft excision, and aortic stump closure, but at the cost of substantial mortality and amputation rates. Alternatives to this strategy include in situ prosthetic replacement in the infected area, as well as autogenous reconstructions. Inherent to all of these procedures, however, is either the creation of an aortic stump, which carries a significant risk of subsequent blowout, or the placement of a bypass conduit in the infected field, thereby maintaining the potential for subsequent infectious complications. To avoid such problems, we have used retroperitoneal in-line aortic bypass with polytetrafluoroethylene through dean tissue planes. METHODS: Since 1987 we have treated 16 graft infections in this manner. The surgical approach consisted of obtaining retroperitoneal proximal aortic control outside of the infected field (above or below the renal arteries), followed by infrarenal division and oversewing of the distal aorta. A polytetrafluoroethylene bifurcated graft was then sewn to the proximal aorta and tunnelled through the psoas sheath laterally to the profunda femoris artery on the ipsilateral side and via the space of Retzius to the contralateral appropriate femoral vessel, so as to avoid any contact with the infected areas. After the closure of the wounds, a plastic barrier was placed over all incisions and the patient was placed supine. The old infected graft was removed transperitoneally. Extensive cultures were taken at various sites to demonstrate no cross-contamination. RESULTS: All patients were followed-up clinically and with tagged white cell scans at 6-month intervals. There were no immediate postoperative deaths and no amputations. One patient had a myocardial infarction and died at 5 months, and a second patient died at 2 months. Of the remaining 14 patients, none had recurrent sepsis and all have had negative Indium-labeled white cell scans in follow-up. Eleven (78%) are still alive, with a mean follow-up of 32 months (range, 20 to 106 months). CONCLUSIONS: In-line aortic bypass for treatment of aortic graft infections yields excellent results and has become our treatment of choice in dealing with this difficult problem.

Aged↗
PubMed1997

A critical approach for longitudinal clinical trial of stretch PTFE aortic grafts.

Adaptation of new clinical products should be based upon thorough scientific evaluation of properties and performance in vitro and in vivo. Developmental animal research experimentation is classically carried out by the manufacturer with eventual government approval. However, objective data needs to be recorded during clinical trials including handling characteristics, bleeding, tensile strength, kinking, seamline break, dilatation, anastomotic deterioration, patency, and incorporation. Since April 1991, 1010 stretch polytetrafluoroethylene (PTFE) aortic grafts have been implanted at our institution and data were recorded prospectively. Six hundred and seven were for elective abdominal aortic aneurysms, 46 for symptomatic abdominal aortic aneurysms, 58 for ruptured abdominal aortic aneurysms, 17 for elective thoracoabdominal aneurysms, 3 for ruptured thoracoabdominal aneurysms and the remainder were for various aortoiliac pathology. Average age of the patients was 69 (range: 10-95), 66% were males, 25% were diabetics. Overall operative mortality was 5.8% (2.9% in elective cases and 26.6% in emergent cases). There were 23 occlusions; 21 were revised and 2 were replaced with axillofemoral bypasses. Estimated blood loss was 784 cc in elective cases and 1918 cc in emergent cases. Grafts were followed by duplex ultrasound or CT scan every 3 months during the first year and every 6 months thereafter. There were no graft dilatations or false aneurysms in this series. There was one graft infection and no perigraft seromas or anastomotic deteriorations during this follow up. Follow up was complete in 94% of these patients. In conclusion, stretch PTFE graft has acceptable handling characteristics, no excessive bleeding at the suture line and had no anastomotic or graft dilatation. This graft material was suitable for thoracic, visceral, renal and abdominal aortic reconstructions.

Adolescent↗