Biomedical subjects

Manish Mehta

Publications and source records attributed to Manish Mehta.

At least 19 recordsLinked to original sources

PubMed2006

Establishing a protocol for endovascular treatment of ruptured abdominal aortic aneurysms: outcomes of a prospective analysis.

PURPOSE: In our transition from elective abdominal aortic aneurysm (AAA) to emergent ruptured AAA (r-AAA) repair with endovascular techniques, we recognized that the availability of endovascularly trained staff in the operating rooms and emergency departments, and adequate equipment were the limiting factors. To this end, we established a multidisciplinary protocol that facilitates endovascular repair (EVAR) of r-AAA. METHODS: In January 2002, we instituted a multidisciplinary approach that included the vascular surgeons, emergency department physicians, anesthesiologists, operating room staff, radiology technicians, and availability of a variety of stent-grafts to expedite EVAR of r-AAAs. Five patients with symptomatic, not ruptured AAAs suitable for EVAR underwent simulation of patients presenting to the emergency department with r-AAAs. Emergency department physicians alerted the on-call vascular surgery team (vascular surgeon, vascular resident or fellow) and the operating room staff, emergently performed an abdominal computed tomography (CT) scan in only hemodynamically stable patients with systolic blood pressures > or =80 mm Hg, and transported the patient to the operating room. The vascular surgeon informed the operating room staff to set up for EVAR and open surgical repair in an operating room equipped with interventional capabilities. The operating room setup was rehearsed with the anesthesiologists, operating room staff, and radiology technicians who were knowledgeable of the sequence of steps involved. Since then, 40 patients have undergone emergent EVAR for r-AAAs with general anesthesia. RESULTS: No complications developed in any of the symptomatic (simulation) patients, and 40 (95%) of 42 patients with r-AAAs had a successful EVAR with Excluder (n = 27, 68%), AneuRx (n = 9, 23%), or the Zenith (n = 4, 10%) stent-grafts. The mean age was 73 years (range, 54 to 88 years), and pre-existing comorbidities included coronary artery disease in 26 (65%), hypertension in 23 (58%), chronic obstructive pulmonary disease in 7 (18%), renal insufficiency not on dialysis in two (5%), and diabetes in nine (23%). Fourteen (38%) patients were diagnosed with r-AAAs at another hospital and subsequently were transferred to us, and 26 (62%) presented directly to the emergency department at our institution. At the initial presentation, 30 patients (75%) were hemodynamically stable and either had a CT scan at an outside hospital or in the emergency department, and 10 (25%) hemodynamically unstable patients with systolic blood pressures <80 mm Hg were rushed to the operating room for EVAR without a preoperative CT scan. The mean time from the presumptive diagnosis of a r-AAA in the emergency department to the operating room for EVAR was 20 minutes (range, 10 to 35 minutes), and the mean operative time from skin incision to closure was 80 minutes (range, 35 to 125 minutes). Seven patients (18%) needed supraceliac aortic occlusion balloon, and six (15%) needed aortouniiliac stent-grafts. The mean blood loss was 455 mL (range, 115 to 1100 mL). Two patients each (5%) developed myocardial infarction, renal failure, and ischemic colitis, seven (18%) developed abdominal compartment syndrome, and seven (18%) died. Over a mean follow-up of 17 months, three patients with endovascular r-AAA repair required four secondary procedures. CONCLUSIONS: The early results show that emergent endovascular treatment of hemodynamically stable and unstable patients is associated with a limited mortality of 18% once a standardized protocol is established. There is an increased recognition of emerging complications with an endovascular approach, and a synchrony of disciplines must be developed to initiate a successful program for endovascular treatment of r-AAAs.

Aged↗

PubMed2006

Combined carotid endarterectomy and coronary artery bypass grafting in patients with asymptomatic high-grade stenoses: an analysis of 758 procedures.

PURPOSE: Surgical treatment of hemodynamically significant carotid artery stenoses has been well documented, especially in the asymptomatic patient. However, in those patients presenting with hemodynamically significant asymptomatic carotid artery disease who are to undergo cardiac surgery, optimal treatment remains controversial. In this study, we analyze our experience with patients who underwent synchronous carotid endarterectomy (CEA) and coronary artery bypass graft procedures (CABG) for hemodynamically significant (>70%) asymptomatic carotid artery stenosis and coronary artery disease (CAD). METHODS: Demographics and outcomes of all patients undergoing synchronous CEA/CABG for asymptomatic carotid stenosis between April 1980 and January 2005 were reviewed from our vascular registry and patient charts. We included patients who underwent standard patching of their carotid artery and those undergoing eversion CEA. All neurologic events within the first 30 days that persisted >24 hours were considered a stroke. For purposes of comparison, we also reviewed outcomes for patients undergoing synchronous CEA/CABG for symptomatic carotid stenosis. RESULTS: Asymptomatic carotid artery stenosis (>70%) was the indication in 702 patients (276 women and 426 men) undergoing 758 CEAs. In the asymptomatic group, 22 patients, of which 21 succumbed to cardiac dysfunction, and one died from a hemorrhagic stroke. The overall mortality rate was 3.1%. Seven permanent nonfatal neurologic deficits occurred in this series (1 woman, 6 men). The combined stroke mortality was 4.3%. This compares to a 30-day stroke mortality of 6.1% in 132 symptomatic combined CEA/CABG patients. The difference in stroke mortality in women compared with men was not significant. CONCLUSION: In this experience, patients presenting with hemodynamically significant (>70%) asymptomatic carotid artery stenosis can undergo synchronous CEA/CABG with low morbidity and mortality.

Age Factors↗

PubMed2005

Infrarenal abdominal aortic aneurysm repair via endovascular versus open retroperitoneal approach.

The beneficial effects of open surgical abdominal aortic aneurysm (AAA) repair via a left retroperitoneal approach have been established. We compared the short-term outcome of infrarenal AAA repair via an endovascular approach with that of an open retroperitoneal approach. From October 2001 to April 2003, patients with infrarenal AAA >5 cm were offered repair via an endovascular approach (group I) with a variety of industry-made stent grafts or with an open retroperitoneal surgical approach (group II). Data were prospectively collected in the vascular registry and complications were analyzed. Data comparison between the two groups was done by using chi-squared analysis and two-tailed Students t-test. Statistical significance was identified at p < 0.05. Over an 18-month period, 492 patients underwent evaluation for AAA. Of these, 446 patients had infrarenal AAA and underwent either endovascular (group I: n = 175, male 85%, female 15%) or open surgical repair (group II: n = 232, male 74%, female 26%) via a left retroperitoneal approach. Group I patients had a higher incidence of coronary artery disease (66% vs. 35%, p < 0.05), hypertension (74% vs. 43%, p < 0.05), chronic obstructed pulmonary disease (29% vs. 12%, p < 0.05), and diabetes mellitus (20% vs. 7%, p < 0.05), a lower mean amount of intraoperative blood loss (277 cc vs. 1452 cc, p < 0.05), and shorter length of stay in the hospital (1.7 days vs., 7.3 days, p < 0.05). Group I also had fewer complications of myocardial infarction (1.7% vs. 5.2%, p = NS), renal failure (0% vs. 2.6%, p < 0.05), pulmonary failure (1.7% vs. 2.6%, p = NS), ischemic colitis requiring colectomy (0.6% vs. 2.6%, p < 0.05), multisystem organ failure (0% vs. 1.3%, p = NS), and death (0.6% vs. 1.3%, p < 0.05). Despite increased preexisting comorbidities, patients undergoing endovascular aneurysm repair had less morbidity, mortality, and blood loss and a shorter in-hospital length of stay than patients undergoing open surgical aneurysm repair via a left retroperitoneal approach.

Abdominal Pain↗

PubMed2005

Safety and efficacy of eversion carotid endarterectomy for the treatment of recurrent stenosis: 20-year experience.

Current options for treating recurrent carotid stenosis (RCS) include standard longitudinal arteriotomy and patch angioplasty with or without carotid endarterectomy (s-PCEA), carotid-carotid bypass, or carotid angioplasty and stent (CAS). Eversion carotid endarterectomy (e-CEA) is an effective procedure for treating primary carotid stenosis, yet it has not been reported for treating RCS. We evaluated the feasibility and outcome of e-CEA for treating of RCS in comparison to s-PCEA. The records of all patients undergoing elective CEA for symptomatic and asymptomatic high-grade RCS from January 1981 to July 2002 were reviewed. Although during the earlier period s-PCEA was performed preferentially, this paradigm changed to e-CEA being the preferred technique for treatment of RCS. During the course of postoperative follow-up when duplex sonography suggested high-grade RCS, the diagnosis was confirmed via arteriography. Data on cranial nerve injury, recurrent stenosis, stroke, and death were prospectively collected into a vascular registry database and analyzed retrospectively, Students' t-test and chi-square analysis were used to compare the group's baseline characteristics and outcomes. Over a 21-year period, 7001 patients underwent primary CEA for symptomatic (n = 2405, 34%) or asymptomatic (n = 4596, 66%) high-grade stenosis via standard (n = 1501, 21%) or eversion (n = 5500, 79%) techniques. Fifteen (25%) patients had 70 to 80% stenosis, 30 (51%) had 81 to 90% stenosis, and 14 (24%) had 91 to 99% stenosis. During this time period, 59 patients presented with symptomatic (n = 18, 31%) or asymptomatic (n = 41, 69%) high-grade RCS and underwent operative repair via s-PCEA (n = 22, 37%) or eversion (n = 37, 63%) techniques. The mean time interval for repeat carotid surgery for RCS was 49 months in the s-PCEA group and 48 months in the e-CEA group. Permanent cranial nerve injuries, stroke, and recurrent restenosis occurred in one (4.5%), one (4.5%), and one (4.5%) of the patients undergoing s-PCEA, respectively. In the e-CEA group, these events occurred in one (27%), none (0%), and one (2.7%) patients, respectively, There were no deaths during the 30-day postoperative period. Eversion CEA is a feasible option for the treatment of many RCSs and can be performed safely with a low rate of cranial nerve injury, recurrent stenosis, stroke, and death.

Aged↗

PubMed2005

Factors associated with abdominal compartment syndrome complicating endovascular repair of ruptured abdominal aortic aneurysms.

BACKGROUND: Endovascular treatment of ruptured abdominal aortic aneurysms (r-AAAs) has the potential to offer improved outcomes. As our experience with endovascular repair of r-AAA evolved, we recognized that the development of abdominal compartment syndrome (ACS) led to an increase in morbidity and mortality. We therefore reviewed our experience to identify risk factors associated with the development of ACS. METHODS: From January 2002 to December 2004, 30 patients underwent emergent endovascular repair of r-AAA by using commercially available stent grafts. All patients who developed ACS underwent emergent laparotomy. Physiological and clinical parameters were analyzed between patients with and without ACS after endovascular r-AAA repair. RESULTS: Over the past 3 years, 30 patients underwent endovascular r-AAA repair, and 6 (20%) patients developed ACS. Patients with ACS had a higher incidence of the need for aortic occlusion balloon (67% vs 12%; P = .01), a markedly longer activated partial thromboplastin time (128 +/- 84 seconds vs 49 +/- 31 seconds; P = .01), a greater need for blood transfusion (8 +/- 2.5 units vs 1.8 +/- 1.7 units; P = .08), and a higher incidence of conversion to aortouni-iliac devices because of ongoing hemodynamic instability and an inability to expeditiously cannulate the contralateral gate (67% vs 8%) when compared with patients without ACS. The mortality was significantly higher in the patients with ACS (67%; 4 of 6) compared with patients without ACS (13%; 3 of 24; P = .01). CONCLUSIONS: ACS is a potential complication of endovascular repair of r-AAA and negatively affects survival. Factors associated with the development of ACS include (1) use of an aortic occlusion balloon, (2) coagulopathy, (3) massive transfusion requirements, and (4) conversion of bifurcated stent grafts into aortouni-iliac devices. We recommend that, after endovascular repair of r-AAA, these patients undergo vigilant monitoring for the development of ACS.

Abdomen↗

PubMed2005

Does sac size matter? Findings based on surgical exploration of excluded abdominal aortic aneurysms.

PURPOSE: To prospectively examine the outcomes of excluded abdominal aortic aneurysms (AAA) that continue to expand without evidence of endoleak. METHODS: From 1984 to 1998, 1218 patients underwent operative retroperitoneal exclusion of AAA and aortoiliac reconstructions. During the procedure, the aneurysm sac was ligated proximally, as well as distally, which created an ideal in-vivo model of excluded AAA sacs with or without endoleaks. From January 2002 to June 2003, 15 of these patients were identified as having an increase in AAA sac size with or without an endoleak on duplex ultrasonography. These patients were prospectively evaluated by computed tomography and diagnostic arteriography. Patients with a demonstrable endoleak underwent embolization, and the remainder underwent open surgical exploration. RESULTS: Eight patients had arteriographically demonstrated endoleaks that were treated with coil embolization. The remaining 7 patients (6 men; mean age 76 years, range 68-81) without a demonstrable endoleak underwent elective surgical exploration and sac endoaneurysmorrhaphy. The mean time interval between the original surgery and aneurysm sac exploration was 76 months (range 52-92); during this time, the mean aneurysm sac size increased by 2.7 cm (range 1.3-5.2). The mean sac pressure was 53 mmHg, and the sac walls were noticeably thickened, with markedly dilated vasa vasorum. The sac contained yellow, fibrinous material with clear serous fluid (5 patients without any evidence of retrograde flow) or liquefied thrombus with serosanguinous fluid (2 patients with retrograde flow from lumbar arteries). No AAA sacs were pulsatile. CONCLUSIONS: Continued expansion of excluded AAA sacs can occur from causes other than a missed endoleak. Exudation of fluid from thickened sac wall and vasa vasorum, as well as local enzymatic activity, might lead to the formation of a sac hygroma. Furthermore, these findings raise questions as to the need for surgical exploration of all patients with an enlarging AAA sac in the setting of low sac pressures and no definable endoleak.

Aged↗

PubMed2004

Early carotid endarterectomy after acute stroke.

PURPOSE: Carotid endarterectomy (CEA) after acute stroke is generally delayed 6 to 8 weeks because of fear of stroke progression. This delay can result in an interval stroke rate of 9% to 15%. We analyzed our results with CEA performed within 1 to 4 weeks of stroke. METHODS: Records for all patients undergoing CEA after stroke between 1980 and 2001 were analyzed. Perioperative evaluation included carotid duplex scanning or angiography, and head computed tomography or magnetic resonance imaging. All patients with nonworsening neurologic status, additional brain territory at risk for recurrent stroke, and severe ipsilateral carotid stenosis underwent CEA. Patients were grouped according to time of CEA after stroke: group 1, first week; group 2, second week; group 3, third week; group 4, fourth week. Statistical analysis was performed with the chi(2) test, logistic regression, and analysis of variance. RESULTS: Two hundred twenty-eight patients underwent CEA within 1 to 4 weeks of stroke. Perioperative permanent neurologic deficits occurred in 2.8% of patients in group 1 (72 procedures), 3.4% of patients in group 2 (59 procedures), 3.4% of patients in group 3 (29 procedures), and 2.6% of patients in group 4 (78 procedures). There was no relationship between location or size of preoperative infarct and time of surgery. Only preoperative infarct size correlated with probability of neurologic deficit after CEA (P <.05). CONCLUSION: Incidence of postoperative stroke exacerbation is similar at all intervals. The results are within acceptable limits for treatment of symptomatic carotid stenosis. CEA may be performed within 1 month of stroke with similar results at all intervals during this period.

Acute Disease↗

PubMed2004

Variability of maximal aortic aneurysm diameter measurements on CT scan: significance and methods to minimize.

OBJECTIVES: We noted substantial differences when measuring repeatedly the same abdominal aortic aneurysm (AAA) on the same computed tomography (CT) scan. This study quantitated this variability, and methods to minimize it were developed. METHODS: The CT maximal diameter of 25 AAAs was measured by eight experienced observers, including six vascular surgeons and two radiologists, using two methods: an unstandardized protocol, and a standardized protocol using fine calipers to carefully measure the largest diameter perpendicular to the estimated aneurysm centerline, from outer aneurysm wall to outer wall. The average measurement difference between observers was calculated for each method. The average difference between each observer's measurement and the official radiology report value was also calculated. Agreement between the two measurement methods was assessed with Bland-Altman plots. RESULTS: The difference in maximal diameter measurements between each observer averaged 4.0 +/- 5.1 mm (range, 0.0-35.0 mm) with the unstandardized method. The mean measurement difference with the standardized protocol was significantly lower, and averaged 2.8 +/- 4.4 mm (range, 0.0-26.0 mm; P<.05). Measurements taken from the official radiology report differed from each of the observer's standardized measurement by an average of 5.0 +/- 6.3 mm (range, 0.0-28.0 mm). This difference was similar for both the unstandardized and standardized methods. Bland-Altman plots confirmed the wide variation of the maximal diameter measurements when the unstandardized method was compared with the standardized method (95% confidence interval, -9-9 mm). CONCLUSIONS: Routine CT maximal diameter measurement of AAAs can have substantial interobserver variability. Standardized measurement protocols can decrease, but not eliminate, this measurement variability. Thus apparent size changes based on CT measurements may represent measurement artifact rather than actual aneurysm growth or shrinkage, particularly when a standardized system is not used.

Aortic Aneurysm, Abdominal↗

PubMed2004

Outcome of aggressive surveillance colonoscopy in ruptured abdominal aortic aneurysm.

PURPOSE: Emergent repair of ruptured abdominal aortic aneurysms (rAAAs) is associated with high perioperative morbidity and mortality. One of the significant complications of this surgery is bowel ischemia. Reports detail mortality as high as 80% when this condition is realized. The objective of this project was to determine both the incidence and the effect of mandatory postoperative colonoscopy on outcome of colon ischemia after rAAA. METHODS: From July 1995 to September 2002 all patients with an rAAA who underwent emergent aortic reconstruction were included in this review. All colonoscopies were performed within 48 hours, ischemia was graded consistently, and treatment was initiated per protocol based on grade of ischemia. Patients with grades I and II ischemia were followed up with medical management and repeat colonoscopy. All patients with grade III ischemia underwent bowel resection. Preoperative, intraoperative, and postoperative variables were collected to assess possible independent risk factors for and predictors of bowel ischemia. RESULTS: Eighty-eight patients underwent emergent aortic reconstruction because of rAAA in the study period. Their mean age was 73 years, and 64 patients (72%) were men. Operative mortality was 42%. Eighteen percent of patients died within 24 hours, and 24% died between 1 and 30 days after surgery. Colonoscopy was performed in 62 of 72 patients who survived more than 24 hours. Bowel ischemia was documented in 26 of the 72 patients (36%). Of these, 16 patients had grade I or grade II ischemia at both initial and repeat endoscopy. Nine patients underwent exploratory laparotomy with bowel resection because of grade III ischemia; two procedures were performed because of worsening ischemia discovered at repeat colonoscopy. In patients with colonoscopic findings of bowel ischemia the mortality rate was 50% (13 of 26 patients). In those with grade III necrosis who underwent resection the mortality rate was 55%. Elevated lactate levels, immature white blood cells, and increased fluid sequestration were all variables associated with the occurrence of colon ischemia. CONCLUSIONS: Bowel ischemia is a frequent postoperative complication (42%) of repaired rAAA. Performing mandatory surveillance colonoscopy in these patients may be associated with a decrease in overall mortality and improved survival in patients with transmural bowel necrosis with no comorbid condition.

Aged↗

PubMed2004

Effects of bilateral hypogastric artery interruption during endovascular and open aortoiliac aneurysm repair.

PURPOSE: Hypogastric artery interruption is sometimes required during aortoiliac aneurysm repair. We have not experienced some of the life-threatening complications of pelvic ischemia reported by others. Therefore we analyzed our experience to identify factors that help minimize pelvic ischemia with unilateral and bilateral hypogastric artery interruption. METHODS: From 1995 to 2003, 48 patients with aortoiliac aneurysm required interruption of both hypogastric arteries as part of endovascular (n = 32) or open surgical (n = 16) repair. During endovascular aneurysm repair coils were placed at the origin of the hypogastric arteries, and bilateral hypogastric artery interruptions were staged at 1 to 2 weeks when possible. Open surgery necessitated oversewing or excluding the origins of the hypogastric arteries and extending the prosthetic graft to the external iliac or femoral artery. Collateral branches from the external iliac and femoral arteries were preserved, and patients received systemic heparinization (50 units/kg). RESULTS: There was no buttock necrosis, ischemic colitis requiring colon resection, or death with the bilateral hypogastric artery interruption. Initially buttock claudication developed in 20 patients (42%), but persisted in only 7 patients (15%) at 1 year. New onset of impotence occurred in 4 of 28 patients (14%), and there were no neurologic deficits. CONCLUSIONS: Bilateral hypogastric artery interruptions can be accomplished with limited morbidity. When hypogastric artery interruption is needed during endovascular aneurysm repair, certain principles help minimize pelvic ischemia. These include hypogastric artery interruption at its origin to preserve the pelvic collateral vessels, staging bilateral hypogastric artery interruptions when possible, preserving collateral branches from the femoral and external iliac arteries, and providing adequate heparinization of the patient during these procedures.

Aged↗

PubMed2004

Outcome of popliteal artery aneurysms after exclusion and bypass: significance of residual patent branches mimicking type II endoleaks.

PURPOSE: Popliteal aneurysms (PAs) often are treated with exclusion and bypass. However, excluded aneurysms can transmit systemic pressure from persistent flow through collateral arteries (endoleak), resulting in aneurysm growth and rupture. We used duplex ultrasound scanning for postoperative surveillance more than 2 years after PA repair with exclusion and bypass, to determine the presence of flow and aneurysm growth. METHODS: From 1995 to 2001, 23 patients with 26 PAs (mean diameter, 3.2 cm; range, 1.6-5.6 cm) underwent surgical repair and were available for more than 2 years of follow-up. The popliteal artery was ligated proximal and distal to the aneurysm, and autogenous revascularization was performed. All patients who underwent PA endoaneurysmorrhaphy through a posterior approach were excluded from the study. During long-term follow-up, aneurysm sac flow and size were evaluated with duplex ultrasound scanning, computed tomography, or magnetic resonance angiography, and standard angiography. Patients with increased PA size and persistent flow were offered repair through a posterior approach. RESULTS: Over 7 years, 26 PAs (symptomatic, 11; asymptomatic, 15) treated with aneurysm exclusion and bypass were available for more than 2 years of follow-up (mean, 38 months; range, 24-78 months). In the postoperative period 16 PAs (62%) became thrombosed, 10 (38%) had persistent collateral flow through geniculate vessels, 6 (23%) increased in size, and 3 (12%) ruptured; 1 (4%) resulted in limb loss. Operative findings for all ruptured PAs and 3 of 6 PAs with increased sac size that underwent aneurysm sac exploration and endoaneurysmorrhaphy revealed retrograde flow through geniculate vessels, mimicking type II endoleak. CONCLUSIONS: These findings question the effectiveness of PA exclusion through proximal or distal ligation and bypass. In addition, retrograde flow into the aneurysm sac (ie, type II endoleak after endovascular abdominal aortic aneurysm repair) may transmit systemic pressure that can result in aneurysm rupture. We recommend PA treatment with aneurysm sac decompression and ligation of geniculate vessels whenever possible and routine postoperative surveillance of the excluded aneurysm sac.

Aged↗

PubMed2004

Is elevated creatinine level a contraindication to endovascular aneurysm repair?

PURPOSE: It is widely believed that chronic renal insufficiency (CRI) greatly increases the risk associated with endovascular abdominal aortic aneurysm repair (EVAR) and is a relative contraindication to the procedure and to the use of intra-arterial contrast agents (IACA). We reviewed a 5-year EVAR experience to determine whether the procedure and use of IACA have an important deleterious effect on renal function in patients with and without pre-existing CRI. METHODS: Endovascular aneurysm repair (EVAR) was performed in 200 patients with a variety of endografts, with intra-arterial contrast agents. The patients were retrospectively assigned to three groups on the basis of preoperative serum creatinine concentration (Cr): group 1 (n = 108), Cr less than 1.5 mg/dL (normal range); group 2 (n = 65), Cr 1.5 to 2.0 mg/dL; group 3 (n = 27), Cr 2.1 to 3.5 mg/dL. No patients had undergone hemodialysis. In groups 2 and 3, patients received hydration perioperatively, and received mannitol intraoperatively; no nephrotoxic drugs were administered during the procedure, other than nonionic contrast agent (Omnipaque 350). RESULTS: The incidence of postoperative complications between the three study groups was not statistically different. In group 1 a transient increase in serum Cr (>30% over baseline and >1.4 mg/dL) was noted in three patients (2.7%), two of whom (1.9%) required temporary hemodialysis and one (0.9%) who died of renal failure. In group 2 a transient increase in serum Cr was noted in two patients (3.1%); both patients (3.1%) required temporary hemodialysis, and one patient (1.5%) died of renal failure. In group 3 a transient increase in serum Cr was noted in two patients (7.4%); one patient (3.7%) required temporary hemodialysis, and one patient (3.7%) died of renal failure. Perioperative hypotension significantly increased the risk for elevated serum Cr and death (P <.05), and larger contrast volume was associated with an increase in serum Cr (P <.05) during the postoperative period. CONCLUSIONS: EVAR with intra-arterial contrast agents can be accomplished in patients with chronic renal insufficiency who do not require dialysis, with limited and acceptable morbidity and mortality, similar to that observed with open aneurysm repair. Contrary to other reports in which perioperative precautions were not used, our study shows that with EVAR the risk for worsening renal failure, dialysis, and death is only slightly, and not significantly, greater in patients with preoperative chronic renal insufficiency compared with patients with normal renal function. Perioperative hypotension and increased contrast volume are significant risk factors for postoperative increase in serum Cr and death. With appropriate precautions such as averting perioperative hypotension and limiting the volume of nonionic contrast agents, elevated Cr need not be a contraindication to EVAR with intra-arterial contrast agents.

Aged↗

PubMed2004

Analysis of factors contributing to improved outcome for carotid endarterectomy.

Since carotid endarterectomy was revitalized following the North American Symptomatic Carotid Endarterectomy Trial and Asymptomatic Carotid Atherosclerosis Study, results have improved. However, types of carotid endarterectomy, indications, risk factors, surgical factors, techniques, and other treatment modalities may be associated with outcomes of carotid endarterectomy. The purpose of this study was to identify those factors in a broad-based carotid endarterectomy patient. This study involved review of the data from 3,644 patients undergoing carotid endarterectomy in New York State hospitals. A multivariate statistical model was used to identify significant patient risk factors to examine the association of the process of care and surgical factors, including surgical specialty for outcome of carotid endarterectomy. In-hospital death and stroke rate overall was 1.84%. After adjustment for patient risk factors, specific processes of care, such as eversion endarterectomy, protamine, heparin, or shunt, were associated with lower adverse outcomes relative to patients undergoing carotid endarterectomy without these processes. Similarly, patients undergoing carotid endarterectomy by vascular surgeons had lower adverse outcomes compared to neurosurgeons and general surgeons. This retrospective review showed that processes of care and surgical specialty were significant factors that contributed to outcomes following carotid endarterectomy.

Age Factors↗

PubMed2003

Aortoiliac reconstruction: the retroperitoneal approach and splenic injury.

Exposure of the abdominal aorta through the left retroperitoneum is a well-accepted technique. Unfortunately, splenic injury is a complication of this approach that rarely occurs through a mid-line transabdominal incision. In this series we evaluate the occurrence of splenic injury during left retroperitoneal aortic surgery. The records of all patients undergoing abdominal aortic reconstruction via the left retroperitoneal approach were reviewed from 1988 to 2001. Indications included either abdominal aortic aneurysm (AAA) or aortoiliac occlusive disease (AIOD). Thoracoabdominal aneurysms and visceral aortic reconstructions were excluded. Those patients that required splenectomy for splenic injury were stratified and analyzed for demographics, indications for operation, and other complications. Chi-square analysis was used to determine statistical significance. Over the 13-year study period, 2889 aortic reconstructions were performed. These consisted of 1773 elective AAA repairs, 357 ruptured or symptomatic AAA repairs, and 759 aortofemoral bypasses for AIOD. Splenectomies were performed after aortic repair in 21 (0.7%) patients. Breakdown by indication totaled 11/1773 (0.6%) for elective AAA repair, 7/357 (2.0%) for rupture or symptomatic AAA repair, and 3/759 (0.4%) for AIOD ( p < 0.05). Mortality for patients undergoing elective AAA without splenectomy was 1.9% (34/1762) and with splenectomy was 9.1% (1/11), while it was 3.2% (24/756) for AIOD patients without splenectomy and 14% (1/7) for AIOD patients with splenectomy (all p = NS). Splenic injury can occur in elective and emergent aortic reconstructions performed through the left retroperitoneum. The surgeon should be prepared for splenectomy whenever intraperitoneal blood or hemodynamic instability is identified. Evaluation of the spleen prior to flank closure may be prudent.

Aged↗

PubMed2003

Surgical treatment of coronary subclavian steal syndrome with carotid subclavian bypass.

Coronary subclavian steal syndrome (CSS) results from proximal subclavian artery occlusive disease causing reversal of flow in an internal mammary artery used as conduit for coronary artery bypass leading to myocardial ischemia. Although percutaneous transluminal angioplasty and stent (PTAS) for subclavian lesions has been successful, it is not always feasible. In this study, the results of carotid subclavian bypass (CSB) for symptomatic CSS due to subclavian occlusion and stenosis not amenable to PTAS were analyzed. The records of patients undergoing CSB for CSS between 1991 and 2001 were reviewed. Patients with lesions not amenable to angioplasty or stent were selected for CSB. Degree of preoperative myocardial ischemia was stratified according to New York Heart Association classification. Graft patency was analyzed by life-table methods. Our results showed that CSB for treatment of symptomatic CSS can be performed safely with excellent mid-term durability. In the setting of proximal subclavian artery disease not amenable to PTAS, CSB provides an acceptable means of treatment for symptomatic CSS.

Aged↗

PubMed2003

Open aneurysm repair at an endovascular center: value of a modified retroperitoneal approach in patients at high risk with difficult aneurysms.

OBJECTIVE: This study was undertaken to evaluate elective open abdominal aortic aneurysm (AAA) repair and the role of a modified retroperitoneal approach in a high-volume endovascular center. METHODS: We reviewed prospectively collected data for 175 elective infrarenal open AAA repairs performed over 6 years. A transperitoneal approach was used in 118 procedures, and a modified retroperitoneal approach was used in 57 procedures. The incisional modification, which facilitated repair in patients with massive obesity, scarring, or ventral hernia, included a higher, more posterolateral location in the ninth intercostal space. Risk factors that added to the difficulty of the repair included aneurysms with a short (<1 cm) or no aortic neck in 45 patients; large, angled or flared aortic neck in 32 patients;, tortuous and calcified iliac arteries in 6 patients; morbid obesity in 10 patients; low ejection fraction (15%-30%) in 14 patients; chronic obstructive pulmonary disease, with forced expiratory volume at 1 second less than 55% in 4 patients; previous laparotomy in 18 patients; previous left-sided colectomy in 11 patients; large right iliac aneurysm in 8 patients; large ventral hernia in 8 patients; pelvic irradiation in 4 patients; failed endovascular repair in 5 patients; and previous failed open repair attempt in 2 patients. Many of these factors occurred with significantly greater frequency (P =.04-.001) in the retroperitoneal group. All factors were correlated with outcome. RESULTS: Despite these risk factors, overall 30-day mortality was 3.5% (retroperitoneal group, 3.8%), and mean length of hospital stay was 9 days (retroperitoneal group, 8 days). There was no significant correlation between mortality or length of stay and any of the mentioned risk factors (P >.2). CONCLUSION: In the era of endovascular aneurysm exclusion, open AAA repair is generally used to treat anatomically complex or difficult aneurysms, many of which are present in patients at high risk. Despite this combination of anatomic and systemic risk factors, the modified retroperitoneal approach facilitates treatment in difficult circumstances and enables open AAA repair to be performed with acceptable mortality and morbidity.

Academic Medical Centers↗

PubMed2003

Upper extremity bypass grafting for limb salvage in end-stage renal failure.

OBJECTIVE: Patients with end-stage renal failure and upper-extremity arterial occlusive disease sometimes have painful digital ulceration. We evaluated the efficacy of distal bypass grafting from the brachial artery for limb salvage in this setting. METHODS: All patients with end-stage renal disease with painful digital ulceration or gangrene of the hand seen from 1992 to 2002 were evaluated with clinical examination and noninvasive studies. Those with evidence of occlusive disease underwent conventional angiography. Individuals with forearm occlusive disease underwent bypass grafting, from the brachial artery to either the distal radial artery or ulnar artery at the level of the wrist or proximal hand. Follow-up was scheduled at regular intervals, and included duplex scanning. Limb salvage and bypass graft patency were determined with life table analysis. RESULTS: Over 10 years, 18 forearm bypass procedures were performed in 15 patients. The outflow artery was the radial artery in 15 procedures and the ulnar artery in 3 procedures. Bypass conduit was autogenous in all patients. No patient had a functioning arteriovenous fistula at bypass grafting; six limbs had previously occluded fistulas. Two bypass grafts (11%) occluded in the early postoperative period, with resultant progression of gangrene. In the remaining 16 grafts patency was maintained (mean follow-up, 18 months), with pain control and tissue healing. CONCLUSION: Treatment in patients with renal failure with upper extremity occlusive disease may be facilitated with brachiodistal bypass grafting. Pain control and reversal of progression of hand necrosis can be achieved.

Adult↗

PubMed2003

Does transrenal fixation of aortic endografts impair renal function?

OBJECTIVES: Transrenal fixation (TFX) of aortic endografts is thought to increase the risk for renal infarction and impaired renal function. We studied the late effects of TFX on renal function and perfusion. METHODS: Of 189 patients with commercial aortic endografts, which we inserted between 1995 and 2002, we reviewed data for 130 patients (112 men, 18 women) with available creatinine (Cr) concentration and contrast enhanced computed tomography (CT) scans preoperatively and 1 to 97 months after the procedure. Of the 130 patients, 69 patients had TFX and 61 patients had infrarenal fixation (IFX). Both groups were physiologically comparable. Average age was 76 +/- 8 years for patients with TFX and 75 +/- 8 years for patients with IFX. Presence of renal infarct or renal artery occlusion was determined by nephrograms on serial contrast-enhanced CT scans. RESULTS: Mean follow-up was 17 +/- 16 months (range, 1-54 months) for TFX and 21 +/- 21 months (range, 1-97 months) for IFX. Mean serum Cr concentration increased significantly during long-term follow-up in both groups (TFX, 1.3 +/- 0.5 mg/dL to 1.5 +/- 0.8 mg/dL, P <.01; IFX, 1.3 +/- 0.7 mg/dL to 1.4 +/- 0.8 mg/dL, P <.03). Creatinine clearance (CrCl) similarly decreased over long-term follow-up in both groups (TFX, 53.3 +/- 17.7 mL/min/1.73 m(2) to 47.9 +/- 16.2 mL/min/1.73 m(2), P <.01; IFX, 58.1 +/- 22.7 mL/min/1.73 m(2) to 53.1 +/- 23.4 mL/min/1.73 m(2), P <.02). There were no significant differences in the increase in Cr concentration (P =.19) or decrease in CrCl (P =.68) between TFX and IFX groups. Small renal infarcts were noted in four patients (5.8%) in the TFX group and one patient (1.6%) in the IFX group. No increase in Cr concentration or decrease in CrCl was noted in any patient with a renal infarct. Postoperative renal dysfunction developed in 7 of 69 patients (10.1%) in the TFX group and 7 of 61 patients (11.5%) in the IFX group. There were no statistically significant differences between groups with respect to number of patients with new renal infarcts (P =.37) or postoperative renal dysfunction (P =.81). CONCLUSION: There is a slight increase in serum Cr concentration and decrease in CrCl after aortic endografting. However, there was no significant difference in these changes between patients with TFX and IFX. Although TFX may produce a higher incidence of small renal infarcts, these do not impair renal function. Thus our midterm results suggest that TFX can be performed safely, with no greater change in renal function than observed after IFX.

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