Isolated inferior mesenteric artery revascularization for chronic visceral ischemia.

PURPOSE: Complete visceral artery revascularization is recommended for the treatment of chronic visceral ischemia. However, in rare cases, it may not be possible to revascularize either the celiac or superior mesenteric (SMA) arteries. We have managed a series of patients with isolated revascularization of the inferior mesenteric artery (IMA) and now report our experience gained over a period of three decades. METHODS: Records were reviewed from 11 patients with chronic visceral ischemia who underwent isolated IMA revascularization (n = 8) or who, because of failure of concomitant celiac or SMA repairs, were functionally left with an isolated IMA revascularization (n = 3). All the patients had symptomatic chronic visceral ischemia documented with arteriography. Five patients had recurrent visceral ischemia after failed visceral revascularization, and two patients had undergone resection of ischemic bowel. The celiac or the SMA was unsuitable for revascularization in five cases, and extensive adhesions precluded safe exposure of the celiac or the SMA in five cases. IMA revascularization techniques included: bypass grafting (n = 4), transaortic endarterectomy (n = 4), reimplantation (n = 2), and patch angioplasty (n = 1). RESULTS: There was one perioperative death, and the remaining 10 patients had cured or improved conditions at discharge. One IMA repair thrombosed acutely but was successfully revascularized at reoperation. The median follow-up period was 6 years (range, 1 month to 13 years). Two patients had recurrent symptoms develop despite patent IMA repairs and required subsequent visceral revascularization; interruption of collateral circulation by prior bowel resection may have contributed to recurrence in both patients. Objective follow-up examination with arteriography or duplex scanning was available for eight patients at least 1 year after IMA revascularization, and all underwent patent IMA repairs. There were no late deaths as a result of bowel infarction. CONCLUSION: Isolated IMA revascularization may be useful when revascularization of other major visceral arteries cannot be performed and a well-developed, intact IMA collateral circulation is present. In this select subset of patients with chronic visceral ischemia, isolated IMA revascularization can achieve relief of symptoms and may be a lifesaving procedure.

Reoperation for recurrent chronic visceral ischemia.

PURPOSE: Recurrent visceral ischemia after a failed visceral revascularization occurs in up to one third of patients, yet no comprehensive report has described the management of this problem. The purpose of this study was to examine the presentation, surgical management, and outcome of patients with recurrent visceral ischemia. METHODS: Between 1959 and 1997, 109 patients underwent primary visceral revascularization at the University of California, San Francisco. Nineteen patients (17.4%) had recurrent visceral ischemia (12 chronic visceral ischemia, seven acute visceral ischemia). Fourteen additional patients with recurrent chronic visceral ischemia were referred after failed primary revascularization (two patients underwent multiple operations before referral). Thirty visceral reoperations were performed for recurrent visceral ischemia in 24 patients (10 patients with recurrence at University of California, San Francisco, 14 referred patients). Symptom-free and overall survival rates were determined by life table analysis. RESULTS: Of seven patients (6.4%) who had recurrent acute visceral ischemia, six (85.7%) died of bowel infarction. Twelve patients (11%) had recurrent chronic visceral ischemia. Patients with recurrent chronic visceral ischemia received their diagnoses earlier and lost less weight than at their initial presentation (p = 0.004 and 0.001, respectively). Recurrent ischemia was associated with younger age, greater weight loss, and modification of surgical technique at the time of initial operation (p = 0.5, 0.009, and 0.02, respectively). For 20 (90.9%) of the 22 first reoperations, antegrade aortovisceral bypass (n = 10) or transaortic visceral endarterectomy (n = 10) was used. Multiple techniques (four antegrade bypass, two retrograde bypass, one endarterectomy, one anastomotic revision) were used in the eight second or third reoperations. Postoperative mortality and complication rates were 6.7% and 33.3%, respectively. Symptoms recurred in six of 22 patients (27.3%) after the first reoperation, three of whom were cured or improved after additional reoperations. The life table symptom-free survival rate after reoperation was 77.3% and 62.8% at 1 and 5 years, respectively. The life table overall survival rate after reoperation was 74.6% at 5 years. CONCLUSIONS: Recurrent visceral ischemia is not uncommon after primary visceral revascularization. These results show that reoperation for recurrent chronic visceral ischemia can be accomplished safely and effectively with established revascularization techniques. Furthermore, after repeat visceral revascularization patients achieve durable relief of symptoms and have life expectancy rates comparable with those of patients who undergo primary visceral revascularization.

Secondary aortoenteric fistula: contemporary outcome with use of extraanatomic bypass and infected graft excision.

PURPOSE: The standard treatment for secondary aortoenteric fistula (SAEF) has been infected graft removal (IGR) and extraanatomic bypass (EAB), an approach criticized for its high rate of death, amputation, and disruption of aortic closure. Recently, graft excision and in situ graft replacement has been proposed as a safer treatment alternative. Because the current outcome that can be achieved by use of the standard treatment of SAEF has really not been established, we reviewed the records of 33 patients treated for SAEF at our institution during a contemporary time interval (1980 to 1992). METHODS: Thirteen patients (39.4%) were admitted with evidence of gastrointestinal bleeding and infection, whereas nine (27.3%) only had bleeding, 10 (30.3%) only had signs of infection, and one SAEF was entirely occult (graft thrombosis). Four patients required emergency operation. The fistula type was anastomotic in 13 (39.4%) patients, paraprosthetic in 15 (45.5%), and not specified in 4 cases. Thirty-two patients underwent EAB followed immediately by IGR (n = 16, 48.5%) or followed by IGR after a short interval, averaging 3.9 days (n = 16, 48.5%). The final patient underwent IGR, followed by EAB. RESULTS: Follow-up on 31 patients (93.9%) averaged 4.4 +/- 3.7 years. There were nine deaths (27.3%) resulting from the SAEF, six perioperative and three late. Three patients (9.1%) had disrupted aortic closure. There were four amputations in three patients (9.1%), two perioperative and two late. Late EAB infection occurred in five patients (15.2%), leading to one death and one amputation. EAB failure occurred in six patients, two during operation and four late, leading to one amputation. The cumulative cure rate for this SAEF group was 70% at 3 years and thereafter. Compared with our earlier SAEF experience, this is a decline of 21% in the mortality rate, 19% in aortic disruption, and 27% in limb loss. CONCLUSIONS: We conclude that outcome reports based on SAEF series extending over long time intervals do not accurately represent the results that are currently achieved with standard SAEF treatment with use of EAB plus IGR. This improved outcome is attributed to wide debridement of infected tissue beds, reduced intervals of lower body ischemia, and advances in perioperative management. To determine whether any new treatment approach actually offers improved outcome in the management of SAEF, comparison with EAB plus IGR should be limited to patients treated within the last decade at most.

Histopathological characteristics of explanted human prosthetic arterial grafts: implications for the prevention and management of graft infection.

OBJECTIVE: to study the histopathological characteristics of prosthetic vascular graft infection. DESIGN: prospective clinical study over 2 years. SETTING: University Hospital. MATERIALS: 36 infected and 29 uninfected (control) chronically implanted vascular prostheses (half aortic) were removed and 352 sections prepared. CHIEF OUTCOME MEASURES: light microscopy (multiple stains), scanning electron microscopy (SEM), and multiple culture techniques to identify characteristics of healing, infection, and microorganisms. MAIN RESULTS: Acute inflammation (AI) (neurophils, granulocytes and necrosis) were seen in 75% of infected grafts, were most prominent in the perigraft tissue and rarely seen on the luminal surface. These were usually well localised, leaving the remainder of a graft well incorporated with no signs of infection. In 25% of clinically infected, culture-positive grafts there was no significant acute inflammation. Chronic inflammation (CI) (macrophages, lymphocytes, monocytes, giant cells) was seen in 70% of both control and infected grafts. In 50% of both groups a significant lymphocytic population was composed exclusively of T-lymphocytes suggesting a true host vs graft response. Unincorporated chronically implanted grafts (> 1 yr) were seen with equal frequency in the two groups although more diffusely unincorporated grafts were infected. Microorganisms were cultured from 23 infected grafts (64%) and were, at microscopy, mostly found outside the graft and nerves on the luminal side. CONCLUSIONS: This data cast doubt on criteria commonly used to distinguish graft infections and host vs. graft reactions from normal graft healing. Acute and chronic inflammation are not predictive of infection.

Elderly, conscious patients have an accentuated hypotensive response to nitroglycerin.

There is no adequate explanation for the highly variable response of systemic blood pressure to nitroglycerin (glyceryl trinitrate [GTN]). Aging produces cardiovascular changes that should alter the effects of GTN, but elderly patients usually have been excluded from studies of GTN. Accordingly, the authors compared the effects of GTN on systemic blood pressure in elderly and younger patients. Fifty-three patients, aged 49-87 (with 30 patients older than 70), were studied. Before elective vascular surgery, 14 patients received an infusion of placebo; 26, a constant infusion of GTN; and 13, a stepwise increasing infusion of GTN. After a standardized anesthetic induction and the start of surgery, the identical infusion protocols were repeated in each group. Data on GTN infusion rate, arterial blood pressure, and GTN concentrations versus time, age, and other potentially influencing variables were pooled for analysis. Before anesthesia and surgery, GTN more commonly caused excessive hypotension in patients older than 70 yr than in younger patients, but none of the patients had complications. A repeated-measures model analysis indicated that age significantly influenced the effects of GTN on blood pressure. That is, patients who are in their 70s who receive 0.5 micrograms.kg-1.min-1 of GTN are predicted to experience a twofold greater decrease in systolic arterial pressure (approximately 33 mmHg) than patients in their 50s. However, no apparent effect of age on intraoperative GTN responsiveness was discernible nor was a predictable relationship found between the preoperative and intraoperative responsiveness or between arterial concentrations of GTN and blood pressure or age. Therefore, the authors conclude that, in the absence of the effects of anesthesia and surgery, elderly patients have a more pronounced blood pressure response to GTN than younger patients. Furthermore, the authors conclude that preoperative blood pressure responsiveness to GTN is not a reliable predictor of intraoperative responsiveness.

Isolated thigh claudication as a result of fibromuscular dysplasia of the deep femoral artery.

Isolated thigh claudication as a result of fibromuscular dysplasia of the deep femoral artery has not previously been reported. This case report describes a patient with fibromuscular dysplasia of the carotid arteries in whom progressive unilateral thigh claudication developed despite normal femoral pulses. Deep femoral artery occlusion caused by fibromuscular dysplasia was successfully treated by common femoral to distal deep femoral artery bypass. Fibromuscular dysplasia of the infrainguinal arteries is rare but should be included as a possible cause of lower extremity ischemic symptoms.

The role of arterial reconstruction in spontaneous renal artery dissection.

Spontaneous renal artery dissection is an uncommon cause of renovascular hypertension, usually associated with fibromuscular dysplasia. Among reported nonautopsy cases (N = 80), arterial reconstruction has seldom been attempted (N = 21) and the outcome has frequently been poor (48% clinical failure rate). This is attributed in part to the frequent involvement of renal artery branches by the dissection. Furthermore, the report of spontaneous reversion to normotension among patients treated medically has also clouded the role of surgery in this disease. Since progress in the technique of renal artery repair now allows successful treatment of anatomically complex lesions, we reviewed our experience with arterial reconstruction in the management of spontaneous renal artery dissection to determine the frequency of and factors correlating with cure after operative repair. Ten patients (eight men, two women; mean age, 39.3 +/- 5.9 years) were admitted with severe hypertension (10/10), often associated with neurologic symptoms, hematuria, or flank pain (8/10). Serum creatinine was elevated in only two patients. Angiography demonstrated changes consistent with fibromuscular dysplasia in 7 of 10 patients and evidence of dissection in 6 of 10. Bilateral disease was present in three patients. Only five patients had a single renal artery on the involved side. The dissection extended into the primary branches in 8 of 10 patients and involved both renal arteries in four of the five patients with two arteries. Histologic study confirmed fibromuscular dysplasia in six and intramural dissection in all operative specimens. Five patients underwent revascularization (in one case requiring the ex vivo technique), with use of hypogastric artery as a conduit in four of five or resection and primary reanastomosis in one of five. Three patients became normotensive, and two returned to their previous level of blood pressure control. Follow-up averaged 14.5 years. Two patients underwent nephrectomy after exploration demonstrated nonreconstructible vessels, and two underwent nephrectomy when intraoperative assessment of the kidney showed that revascularization had failed to adequately reverse extensive renal ischemia. After a mean follow-up of 14.6 years these patients remain normotensive, although two require antihypertensive medications. One patient was treated medically and is currently hypertensive off all medications. Nine of 10 patients have maintained a normal serum creatinine during follow-up. We conclude that renal revascularization is frequently successful in spontaneous renal artery dissection (five of seven, 71.4%) and results in sustained relief of hypertension with maximal conservation of renal tissue. This is important because of the young age at onset and the not infrequent occurrence of bilateral fibromuscular dysplasia, and even of dissection.(ABSTRACT TRUNCATED AT 400 WORDS)

Clinical spectrum of symptomatic external iliac fibromuscular dysplasia.

External iliac fibromuscular dysplasia is a rare and usually asymptomatic disorder. We report eight symptomatic patients seen over a 15-year period and review pathophysiologic mechanisms accounting for the three following distinct lower extremity ischemic sequelae: (1) Emboli--episodic focal digital ischemia (blue toe) was seen in three patients. Resection and primary anastomosis of focal iliac ulcerative fibromuscular dysplasia (one patient) or resection and replacement (two patients) removed the embolic source and relieved the symptoms. (2) Chronic ischemia--gradual onset of full leg claudication in four patients was treated by operative graduated intraluminal dilation in three patients and prosthetic bypass in one. Arteriography subsequently showed a remodeled lumen in the three patients who underwent dilation. (3) Dissection--acute onset leg ischemia resulted from presumed dissection of the external iliac segment. After 4 months of conservative management of antiplatelet agents and exercise, symptoms resolved completely, and arteriogram showed spontaneous restoration of a normal lumen in the dissected segment. The clinical presentation of fibromuscular dysplasia may mimic other arterial processes such as atherosclerosis. Diagnosis is made only by arteriography with specific magnification views of the external iliac arteries and careful surveillance of the renal arteries. Appropriate treatment should be tailored to the clinical presenting symptom. For microembolic disease, resection and replacement are required. For chronic ischemia, intraluminal dilation is generally sufficient and durable and has proved to be a simpler and acceptable alternative to replacement or bypass. In acute dissection, surgical intervention may be deferred if the limb is viable to allow spontaneous healing and remodeling. Persistent symptoms may be the only indication for intervention in this ischemic manifestation of external iliac fibromuscular dysplasia.

Recurrent carotid stenosis: a consequence of local or systemic factors? The influence of unrepaired technical defects.

To determine the influence of unrepaired technical defects as well as systemic risk factors for atherogenesis on carotid artery healing after endarterectomy, we conducted a prospective study using intraoperative duplex scanning with spectral analysis to establish the initial status of the artery (N = 131 arteries), and then we studied these vessels at regular postoperative intervals with the same technique (N = 108 arteries, 265 studies). The vessels were divided into the operated and nonoperated segments of the common, internal, and external carotid arteries, and both intraoperative image and flow data were tabulated by artery segment. The technical factors that were analyzed included defect size, defect type, adjacent segment defects, number of defects, shunt use, vessel reopening, and peak, mean, and end-diastolic frequency and velocity. The systemic risk factors studied were sex, hypertension, diabetes, smoking, randomly drawn total serum cholesterol and triglyceride levels, and perioperative aspirin and dextran use. Data were analyzed by linear logistic regression analysis. Among the technical factors, only intraoperative defect size was significantly associated with risk of recurrent stenosis (p = 0.0175). Although any defect size adversely affected the condition of the vessel during follow-up, the magnitude of this effect was small for smaller defects (size category 1: less than or equal to 40% stenosis or flap length less than or equal to 25% of vessel diameter). The systemic factors that were associated with risk of recurrent stenosis were hypertension (p = 0.0002), smoking (p = 0.0016), and randomly drawn total serum cholesterol level (p = 0.0116). The fact that the operated segments consistently fared worse during follow-up than did the nonoperated segments (p = 0.0044) undoubtedly reflects the inevitable trauma of the endarterectomy, but also emphasizes the important contribution of systemic risk factors in recurrent carotid stenosis. Risk factor modification may be the most effective method of ensuring the durability of carotid endarterectomy.

Infrarenal aortic occlusion: does it threaten renal perfusion or function?

Proximal propagation of aortic thrombus with resultant impaired renal perfusion has been considered a significant risk of untreated infrarenal aortic occlusion. To investigate this question, we studied 52 patients surviving 1 year or more after surgical interruption of the infrarenal aorta in the course of treatment of aortic graft infection. Blood pressure, renal function, and renal artery anatomy were studied before and after aortic interruption. Preoperatively, 20 patients (38.4%) had treated hypertension, and 11 (21.2%) had impaired renal function (creatinine greater than 1.3 mg/dl). In 46 patients (88.4%) with angiography before aortic interruption, 31 (67.4%) had normal renal arteries, whereas 15 (32.6%) demonstrated renal artery stenosis of less than or equal to 50% (N = 10) or greater than 50% (N = 9). Concomitant renal revascularization (N = 3) or nephrectomy (N = 1) were rare. All patients were monitored after surgery for a mean period of 39.2 months. Thirty-three (63.5%) remain alive and well; 19 (36.5%) have died of causes not related (N = 15) or indirectly related (N = 4) to the original graft infection. Forty-eight patients (92.3%) had late assessment of their blood pressure (N = 44, mean follow-up of 31.0 months) and/or renal function (creatinine) (N = 42, mean follow-up of 26.1 months). Follow-up aortography in 21 patients (40.4%, mean interval of 27.7 months) demonstrated no instance of suprarenal propagation of aortic thrombus. During follow-up 41 patients (78.8%) had no change in either their blood pressure or serum creatinine. Seven patients (13.5%) developed worsening hypertension (N = 3) or a rising creatinine (N = 4).(ABSTRACT TRUNCATED AT 250 WORDS)

Particle size distribution of lipoproteins from human atherosclerotic plaque: a preliminary report.

It is commonly believed that low-density lipoproteins (LDLs) carry cholesterol into the artery wall. In addition, some epidemiologic studies have suggested that triglyceride-rich lipoproteins, such as very-low-density lipoproteins (VLDLs), may be much less important than LDLs in atherogenesis. To determine if VLDLs or their metabolic remnants could have a direct role in the formation of atherosclerotic plaque, we examined lipoproteins isolated from endarterectomy specimens. Atherosclerotic plaque was obtained from eight subjects who underwent aortoiliac endarterectomy (4), aortic aneurysm repair (2), or visceral/renal endarterectomy (2). Plaques were washed extensively, minced, and incubated with a buffered saline solution. Lipoproteins were recovered from this solution via a selected-immunoaffinity column by means of a polyclonal antibody to human LDL (apolipoprotein B-100). Particle sizing from electron photomicrographs of negatively stained specimens indicated that 8% of the lipoprotein particles were the size of plasma VLDL (350 to 800 nm). Thirty-six percent were the size of plasma VLDL remnant particles (250 to 350 nm), and 56% were consistent in size with plasma LDL (175 to 250 nm). We conclude that VLDL- and VLDL remnant-sized particles appear to comprise a significant percentage of the lipoproteins found in human atherosclerotic plaque and could have a direct role in the atherosclerotic process.

Does anesthetic technique make a difference? Augmentation of systolic blood pressure during carotid endarterectomy: effects of phenylephrine versus light anesthesia and of isoflurane versus halothane on the incidence of myocardial ischemia.

Whether anesthetic technique affected the incidence of myocardial ischemia in 60 patients undergoing carotid endarterectomy was investigated. The patients were randomly assigned to receive halothane or isoflurane (with nitrous oxide) either at a low concentration alone or at a higher concentration with phenylephrine added to support blood pressure. Blood pressure was maintained within 20% of each patient's average ward systolic pressure. Seven leads of electrocardiograms (ECG) and echocardiograms were analyzed for segmental wall motion. The echocardiograms were analyzed using standard formulae for end-systolic meridional wall stress (SWS) and rate-corrected velocity of fiber shortening (Vcfc). Because of the nature of these calculations, only echocardiograms with normal regional wall motion could be accurately analyzed. The patients had postoperative ECG and creatinine phosphokinase (CPK) isoenzyme determinations and regularly scheduled clinical examinations to detect perioperative myocardial infarction and neurologic deficits. Although blood pressures were similar, the patients who received a higher concentration of anesthetic plus phenylephrine had a higher wall stress, regardless of the choice of anesthetic agent. All four techniques allowed provision of the same stump pressures (the marker surgeons used for adequacy of collateral carotid flow). No difference could be found in wall stress or incidence of myocardial ischemia between isoflurane and halothane. The patients who received phenylephrine had a threefold greater incidence of myocardial ischemia than did the patients who had light anesthesia to maintain similar systolic blood pressures and stump pressures. The groups were demographically and hemodynamically similar; in particular, the heart rates were not different.(ABSTRACT TRUNCATED AT 250 WORDS)

Evolving strategies for the repair of complex renovascular lesions.

Fifty-five patients with 59 complex renovascular lesions required two or more branch artery anastomoses during aortorenal grafting. Forty-five reconstructions involving 112 branches were facilitated using hypothermic ex vivo perfusion preservation, whereas 14 involving 28 branches were repaired in situ. Ex vivo repair was used whenever the kidney was considered unreconstructable by in situ techniques. Fibromuscular dysplasia predominated and the branched internal iliac artery was used for renal artery substitution. There were no deaths and only one kidney (ex vivo) was lost. Branch vessel occlusion occurred in two of 140 anastomoses (1.4%). Ninety-eight per cent (51/52) of the heparinized patients had cure or improvement at mean follow-up of 5 years. No late graft dysfunction occurred in postoperative angiographic follow-up. The branched internal iliac artery is uniquely suited and remains the preference of the authors for the replacement of the diseased renal artery and its branches. The in situ repair is ideally suited for lesions limited to the renal artery bifurcation. Ex vivo repair is reserved for complex or reoperative distal arterial lesions. Unique characteristics in the group include: bilateral lesions (25%), solitary kidney (22%), reoperative lesions (16%), children (9%), and coexisting significant aortic disease (7%). In situ and ex vivo repair meet all the challenges of complex renovascular disease. The strategies outlined will achieve outstanding long-term total and segmental renal salvage in the treatment of hypertension or aneurysmal disease. When ex vivo repair is required, it can be accomplished with only one additional simple maneuver, the reanastomosis of the renal vein.

Hypercholesterolemia and early restenosis after carotid endarterectomy.

Cellular proliferation in response to endothelial injury has been examined extensively in experimental animals. Under certain conditions (e.g., hypercholesterolemia and hypertension), this response can be exaggerated and develop into lesions that resemble early atherosclerosis. The injury caused by endarterectomy in human beings and the repair of the arterial wall that ensues may be analogous to the animal models. Presumably, those patients with an exaggerated proliferative response manifest myointimal hyperplasia and recurrent stenosis. To determine potential causes of recurrent stenosis after carotid endarterectomy, we studied 31 patients with early restenosis (group I), 35 patients with later restenosis (group II), and compared them with a control group of 100 consecutive patients who underwent uncomplicated carotid endarterectomy (group III). The known risk factors for atherosclerosis were analyzed. There was no significant difference in the male-to-female ratio, number of cigarettes smoked, or incidence of diabetes mellitus. However, the serum cholesterol level for group I was 282 +/- 57 mg/dl (p less than 0.001 versus controls) while the serum cholesterol level in group II was not significantly elevated over that of the control group. Both groups I and II had a higher incidence of hypertension (p less than 0.005 for both versus controls). There were no differences in the severity of hypertension. The data suggest that hypercholesterolemia has a strong association with early restenosis after carotid endarterectomy but not with late recurrent disease and that hypertension, even when treated, may be associated with both early and late recurrent stenosis.

Improved management of aortic graft infection: the influence of operation sequence and staging.

To investigate the influence of operation sequence and staging on the outcome of aortic graft infection, we studied the mortality and amputation rates and incidence of new graft infection involving the extra-anatomic bypass (EAB) among 101 patients treated for secondary aortoenteric fistula (N = 43) or primary perigraft infection (N = 58). Patients were retrospectively grouped according to the operative treatment technique. Seven patients underwent infected graft removal (IGR) followed immediately by EAB (traditional). Fifty-seven patients were revascularized first, followed by immediate IGR in 38 patients (sequential) or by delayed IGR in 19 patients (staged). The median interoperative interval for the staged group was 5 days (range 2 to 31 days). Twenty patients underwent simultaneous IGR and in-line autogenous reconstruction (synchronous) and finally in 15 patients treatment consisted of IGR only with no extremity revascularization (none). The mean follow-up interval for all patients was 36.8 months. There was no statistically significant difference in mortality rate (traditional, 43%; sequential, 24%; and staged, 26%) or incidence of new graft infection (traditional, 43%; sequential, 18%; or staged, 16%) among those patients treated with EAB, although there was a trend toward an improved outcome with either sequential or staged treatment. There was a significantly lower amputation rate among sequential patients (11%) (p = 0.038) but not staged patients (16%) (p = 0.171) when compared with traditional treatment (43%). Staged operative treatment was associated with significantly less physiologic stress than sequential treatment as reflected by multiple perioperative metabolic variables (95% confidence limits). The treatment groups were comparable in the incidence of aortoenteric fistulas, culture-negative infections, emergent procedures, and appropriate antibiotic use. We conclude that reversed sequence or staged operative treatment of infected aortic grafts can be performed with no increased patient risk. Although traditional or sequential treatment may be required in the setting of acute hemorrhage, the staged operative approach is recommended for the treatment of chronic aortic graft infections.

Recurrent carotid stenosis: operative strategy and late results.

From 1957 to 1985, 116 consecutive operations for recurrent carotid stenosis were performed in 99 patients at the University of California, San Francisco. Ninety-four patients underwent 103 reoperations for primary recurrent stenosis (nine patients had bilateral repairs). Seventy-two operations (70%) were performed to relieve cerebrovascular symptoms whereas the indication for 31 operations (30%) was high-grade stenosis. The cause of primary recurrent stenosis was myointimal hyperplasia (MIH) in 47 cases, whereas 56 were caused by recurrent atherosclerosis (ASO). Secondary recurrent stenosis developed in six patients from our own series (5.8%) and an additional six patients were referred after reoperation elsewhere. The 12 lesions in this group were evenly divided between MIH (six) and recurrent ASO (six). MIH resulted in a single tertiary recurrent stenosis. Myointimectomy or repeat endarterectomy and vein patch angioplasty were the most commonly used techniques for repair of a primary recurrent stenosis. Secondary recurrent stenosis necessitated resection of the carotid bifurcation and graft interposition when caused by MIH. Secondary recurrent stenosis caused by ASO could be treated by repeat endarterectomy and vein patch angioplasty in five of six cases. Five strokes occurred in the entire series (4.3%), resulting in two deaths. There were 23 cranial nerve palsies, which rarely persisted beyond 3 months. The morbidity and mortality rates for primary and secondary carotid reoperation are comparable to the original procedure and should not deter the vascular surgeon from reoperative carotid reconstruction whenever indicated.

Intraoperative assessment of renal and visceral artery reconstruction: the role of duplex scanning and spectral analysis.

To refine our ability to assess intraoperatively renal and visceral reconstructions, we have investigated the usefulness of combined duplex scanning and Doppler spectral analysis to determine the technical adequacy and flow characteristics of these repairs. We studied 62 patients (116 arteries) who underwent renal (83 arteries) or visceral (13) reconstruction by transaortic endarterectomy (76), autogenous graft (12) or prosthetic (5) bypass, reimplantation (2), and dilation (1). Twenty-six nonreconstructed vessels were also studied, including preoperative arteries (6), unrepaired arteries (14), and normal renal arteries (donor nephrectomies) (6). Duplex scanning was performed by means of a 7.5 or 10 MHz probe placed in a sterile glove and plastic sleeve. Peak (Vs) and mean (Vm) velocities measured in meters per second were subsequently calculated from frequency spectral analysis. Spectral broadening (SB) and aortic inflow data were also collected and analyzed. There were no complications related to ultrasound scanning. Mean scan time was 7.8 minutes. Fourteen of 26 nonreconstructed vessels (54%) appeared normal by duplex scanning, including all six control (normal) renal arteries. Sixty-five reconstructed arteries (68%) appeared normal, 27 had various minor defects, and four had major defects (three occlusions and one floating thrombus). The major defects were repaired, whereas minor ones were not. Confirmatory studies were obtained in 19 (73%) nonoperated and 73 (76%) operated vessels. There were two false negative duplex studies (sensitivity 89%) and 17 false positive duplex studies--all minor defects (specificity 77%). The predictive value of duplex scans in detecting the presence of confirmed defects was Tau = 0.47 (p = 0.01). Although SB correlated with B-mode imaging alone (Tau = 0.21, p = 0.07), it added no independent value in predicting the results of a confirmatory study. No other variable (Vs, Vm, or aortic inflow) added to the duplex scan in predicting an abnormal confirmatory study. Detailed renal and visceral artery spectral analysis data are provided for validation of this technique and comparison with transcutaneous studies. These data suggest that the requirement for reliable and immediate assessment of renal and visceral reconstructions, particularly those involving transaortic extraction endarterectomy, is satisfied by duplex scanning.

Middle aortic syndrome. Effectiveness and durability of complex arterial revascularization techniques.

Middle aortic syndrome typically occurs as severe hypertension in young patients who have weak or absent femoral pulses and an abdominal bruit. It results from a diffuse narrowing of the distal thoracic and abdominal aorta, commonly involving the visceral and renal arteries. The clinical presentation, angiographic assessment, and surgical outcome of 10 patients (mean age: 19.5 years) who underwent one-stage revascularization for middle aortic syndrome were reviewed to determine the effectiveness and durability of one-stage revascularization techniques to relieve these complications. All patients were hypertensive (mean blood pressure: 176 mmHg); six (60%) had severe, poorly controlled hypertension, two of whom had previous failed operations for renovascular hypertension and one who presented with malignant hypertension and acute renal failure. Five patients had disabling myocardial insufficiency, only one of whom had documented coronary artery disease. Four patients had intermittent claudication. Aortography showed variable length high-grade midaortic stenosis, nine had visceral artery involvement, and eight had renal artery involvement. All patients underwent one-stage revascularization by a variety of autogenous and prosthetic techniques. The postoperative recovery was uncomplicated in eight of nine patients and was often associated with dramatic reduction in blood pressure. There was a single death from disruption of the thoracic anastomosis in a patient who had diffuse cystic medial necrosis of the aorta. Arterial biopsy in nine patients indicated evidence for both acquired and congenital origins of the midaortic stenosis. Late follow-up evaluation (mean: 4.1 years) showed normal growth and development, preservation of renal function, and relief of myocardial insufficiency in all patients. Seven patients (77%) are cured of their hypertension, and two (23%) have only mild hypertension. These results indicate that one-stage revascularization of patients with middle aortic syndrome can result in effective and durable relief of these severe life-threatening complications.