Peter G. Kalman

Mesenteric arterial bypass grafts: Early and late results and suggested surgical approach for chronic and acute mesenteric ischemia

BACKGROUNDnThe purposes of this study were to determine the early and late results of placement of arterial bypass grafts in the treatment of chronic and acute intestinal ischemia and to ascertain whether multiple grafts provide better late results than a single graft.nnnMETHODSnRecords of 34 patients who underwent mesenteric vascular graft placement were retrospectively reviewed.nnnRESULTSnAll 21 patients with chronic ischemia had a history of intestinal angina and weight loss. Food fear was reported by 33% of patients; also, diarrhea in 57%, constipation in 29%, acalculous cholecystitis in 19%, ischemic gastritis or peptic ulcer in 19%, and elevation of liver enzymes in 22% were reported. Angiogram showed more than 50% stenosis or occlusion of the superior mesenteric artery (SMA) in 100% of patients, celiac artery in 90%, and inferior mesenteric artery in 90%. Although not described previously, a reduction in collateral flow from the internal iliac arteries was caused by severe pelvic disease in 56% of patients. There were no in-hospital deaths. The rate of survival at 1 year was 100%; at 2 years it was 93% +/- 6%, at 3 years 86% +/- 9%, at 5 years 79% +/- 11%, and at 10 years 50% +/- 15%. During follow-up, graft thrombosis occurred in three patients. Of the patients who underwent only a single SMA or celiac bypass, two of five died of bowel infarction; only one of 16 patients who underwent both celiac and SMA bypass had to undergo a repeat surgical procedure because of graft occlusion. Three of 16 retrograde bypasses thrombosed, compared with zero of five prograde bypasses. In nine patients who underwent placement of mesenteric bypass grafts because of acute ischemia caused by acute mesenteric thrombosis, the early mortality rate was 22%; the two deaths were the result of bowel ischemia. The cumulative survival rate was 78% +/- 14% at 1 month, 65% +/- 17% at 1 year, and 52% +/- 16% at 5 years. One of the two late deaths was due to graft thrombosis and bowel infarction. Three of four patients who underwent concomitant mesenteric bypass at the time of aneurysm repair or aortobifemoral bypass survived the surgical procedure.nnnCONCLUSIONSnWhen chronic and acute mesenteric ischemia are diagnosed and treated with a bypass graft, the early and late results are good. Complete revascularization of the SMA and celiac artery or pelvis or both and prograde bypass may reduce the risk of late bowel ischemia.

A practical approach to vascular access for hemodialysis and predictors of success

PURPOSEnThe long-term results and predictors of success for vascular access at The Toronto Hospital were studied. This report describes the access program and emphasizes the role of the vascular access coordinator.nnnMETHODSnA total of 384 consecutive patients underwent 466 vascular access procedures. The access program is centered around a dedicated, full-time vascular access coordinator, who is a registered nurse and is responsible for all aspects of access care, including follow-up. Outcome variables were collected prospectively. Primary, primary-assisted, and secondary success was determined by means of Kaplan-Meier analysis, and the stepwise Cox proportional hazards model was used for multivariate analysis of the factors that were independently predictive of primary success.nnnRESULTSnThere were 235 autogenous arteriovenous fistulae (AVFs) and 231 arteriovenous grafts (AVGs). The cumulative primary, assisted-primary, and secondary success (patent and functional for effective dialysis) at 24 months for all 466 cases combined was 36% +/- 3%, 54% +/- 3%, and 66% +/- 3%, respectively. The primary success for AVFs and AVGs at 2 years was 54% +/- 4% and 18% +/- 4%, respectively (P <.001; log-rank test); the primary-assisted success for AVFs and AVGs at 2 years was 62% +/- 4% and 44% +/- 6%, respectively (P <.001; log-rank test); and the secondary success for AVFs and AVGs at 2 years was 70% +/- 4% and 60% +/- 5%, respectively (P =.331; log-rank test). Stratification of variables revealed significant benefit for AVFs (P =.001), the female sex (P =.014), and the absence of diabetes mellitus (P =.001). Multivariate analysis with Cox regression determined that access type (AVF vs AVG; P =.001) and diabetes mellitus (P =.024) were independently predictive of primary success. The improved clinical coordination of access patients with the initiation of the vascular access program resulted in a significant reduction in length of hospital stay before and after the program was organized (2.5 +/- 0.06 vs 1.1 +/- 0.03 days; P =.001).nnnCONCLUSIONnThe organization of a vascular access program in a practical and cost-effective way for reduced length of hospital stay is streamlined through a dedicated access coordinator, who ensures an integrated, multidisciplinary approach. The results for the Cox model is useful when discussing the anticipated results of access procedures with individual patients.

The value of late computed tomographic scanning in identification of vascular abnormalities after abdominal aortic aneurysm repair

PURPOSEnThe purpose of this study was to determine the prevalence of late arterial abnormalities after aortic aneurysm repair and thus to suggest a routine for postoperative radiologic follow-up examination and to establish reference criteria for endovascular repair.nnnMETHODSnComputed tomographic (CT) scan follow-up examination was obtained at 8 to 9 years after abdominal aortic aneurysm (AAA) repair on a cohort of patients enrolled in the Canadian Aneurysm Study. The original registry consisted of 680 patients who underwent repair of nonruptured AAA. When the request for CT scan follow-up examination was sent in 1994, 251 patients were alive and potentially available for CT scan follow-up examination and 94 patients agreed to undergo abdominal and thoracic CT scanning procedures. Each scan was interpreted independently by two vascular radiologists.nnnRESULTSnFor analysis, the aorta was divided into five defined segments and an aneurysm was defined as a more than 50% enlargement from the expected normal value as defined in the reporting standards for aneurysms. With this strict definition, 64.9% of patients had aneurysmal dilatation and the abnormality was considered as a possible indication for surgical repair in 13.8%. Of the 39 patients who underwent initial repair with a tube graft, 12 (30.8%) were found to have an iliac aneurysm and six of these aneurysms (15.4%) were of possible surgical significance. Graft dilatation was observed from the time of operation (median graft size of 18 mm) to a median size of 22 mm as measured by means of CT scanning at follow-up examination. Fluid or thrombus was seen around the graft in 28% of the cases, and bowel was believed to be intimately associated with the graft in 7%.nnnCONCLUSIONnLate follow-up CT scans after AAA repair often show vascular abnormalities. Most of these abnormalities are not clinically significant, but, in 13.8% of patients, the thoracic or abdominal aortic segment was aneurysmal and, in 15.4% of patients who underwent tube graft placement, one of the iliac arteries was significantly abnormal to warrant consideration for surgical repair. On the basis of these findings, a routine CT follow-up examination after 5 years is recommended. This study provides a population-based study for comparison with the results of endovascular repair.

Current indications for axillounifemoral and axillobifemoral bypass grafts

Revascularization of the lower extremities may require an axillofemoral bypass when an aortobifemoral bypass is contraindicated. Thirty-one patients underwent axillounifemoral and 59 had an axillobifemoral bypass, with a mortality rate of 9%. The indication for operation was limb salvage in 67%, intra-abdominal sepsis in 21%, and disabling claudication in 12%. Cumulative survival, patency, and limb salvage rates were determined by life-table analysis. The cumulative patency and limb salvage rates (with standard errors) at 3 years were 68% +/- 8% and 78% +/- 9%, respectively. When stratified for type of operation, axillobifemoral bypass had a superior patency rate compared with axillounifemoral bypass (log rank = 3.882, p less than 0.05). There was no significant difference when patients were stratified for diabetes (log rank = 2.213, p = no significance [NS]), operative indication (disabling claudication vs. limb salvage) (log rank = 0.0005, p = NS), or outflow (no profundaplasty vs. profundaplasty) (log rank = 2.011, p = NS). We conclude that axillofemoral bypass is a reasonable alternative for revascularization in high-risk patients or in those patients in whom a transabdominal approach is contraindicated. We recommend aggressive use of the profunda femoris artery when the superficial femoral artery is occluded to achieve optimal results.

Cardiac dysfunction during abdominal aortic operation: The limitations of pulmonary wedge pressures

The mortality rate for elective abdominal aortic operations remains between 3% and 8% despite careful hemodynamic monitoring, and half of these deaths are cardiac in origin. An extensive evaluation of ventricular function was performed during abdominal aortic operation to detect subtle abnormalities in systolic or diastolic ventricular function that could precipitate progressive ischemic cardiac injury. Twenty-three patients undergoing elective abdominal aortic operations (14 patients with abdominal aortic aneurysm [AAA] and nine patients with aortoiliac occlusive disease [AIOD] ) had hemodynamic and nuclear ventriculographic measurements performed preoperatively, during aortic clamping, and immediately after aortic declamping. No differences were found in the hemodynamic response to operation between patients with AAA or AIOD. Volume loading was performed at each time period to assess ventricular function. Myocardial performance (the relation between cardiac index and end-diastolic volume index) and systolic function (the relation between systolic blood pressure and end-systolic volume index) were depressed during aortic clamping (p less than 0.05), suggesting decreased contractility, but returned to baseline values after declamping. Diastolic compliance (the relation between pulmonary capillary wedge pressure and end-diastolic volume index) decreased after declamping (p less than 0.05), suggesting early myocardial ischemia. The decrease in diastolic compliance rendered pulmonary capillary wedge pressure a poor index of left ventricular preload after declamping. Higher pressures were required to maintain adequate diastolic volumes. Despite careful hemodynamic monitoring, potentially ischemic ventricular dysfunction was found during abdominal aortic operation.

Sociologic factors are major determinants of prolonged hospital stay after abdominal aneurysm repair

BACKGROUNDnWith increasing pressure to optimize the utilization of hospital resources, it is important to identify patients who may have prolonged hospital length of stay (LOS). The purpose of this report was to identify the preoperative variables that are predictive of prolonged postoperative hospital LOS for patients undergoing elective infrarenal abdominal aneurysm repair and to discuss strategies that might assist in minimizing LOS for these patients.nnnMETHODSnThree hundred sixty-five consecutive patients underwent elective infrarenal abdominal aneurysm repair between 1989 and 1994. The relationship between 13 preoperative variables and LOS was analyzed by using both univariate (Kaplan-Meier) and multivariate (Cox regression) statistical techniques.nnnRESULTSnBy using Cox regression a model was developed to estimate LOS (p < 0.001 for model). The independent predictors for prolonged LOS were (1) age older than 70 years and (2) absence of a spouse.nnnCONCLUSIONSnKnowledge of the predictive factors that are associated with prolonged LOS should identify those patients who may require prompt and efficient discharge planning, early consultation with a home care nurse, or transfer to a convalescent facility. This approach may significantly improve the utilization of hospital resources.

Indications and Results of Balloon Angioplasty for Arterial Occlusive Lesions

Abstract. This paper describes the current techniques for percutaneous transluminal angioplasty (PTA) of peripheral arteries, summarizes the long-term results of the procedure, and identifies the variables that are predictive of long-term success of PTA performed in the iliac and femoropopliteal segments.

Indications and Role of Axillofemoral Bypass in High-Risk Patients

The purpose of this study was to determine whether axillofemoral bypass was justified as an alternative revascularization procedure to direct reconstruction and to specifically define the indications for this extraanatomical bypass. Forty-one patients operated on between 1978 and 1985 were evaluated. The average age was 69 years. Indications were based upon limb salvage for aortoiliac occlusive disease in the following situations: infected aortobifemoral bypass graft (8 patients) and high risk with co-existing medical problems (33 patients). Patients were classified according to Goldmans Multifactorial Index of Cardiac Risk and Coopermans Cardiovascular Risk Index. Twenty-four patients had axillobifemoral bypass and 17 had unilateral axillofemoral procedures. In 66 femoral anastomoses there were 13 extended profundaplasties, 25 profunda arterioplasties, 11 profunda patch angioplasties and 16 anastomoses to the common femoral artery. Postoperative mortality was 4.8% (2 patients). Cumulative survival at 60 months was 43% +/- 11% and primary patency rate of the axillofemoral bypass was 69 +/- 9.8%. We conclude that axillo-femoral bypass is indicated in the presence of infection, in patients who fall into Goldmans Class III-IV or in patients with risk greater than 10% as calculated by Coopermans equation.

Consequences of Groin Lymphatic Fistulae After Vascular Reconstruction

Division of lymphatics during femoral arterial exposure may result in a lymphatic fistula. The management of this problem may be conservative or operative, both aimed at stopping the leak of lymphatic fluid and preventing graft contamination. The authors purpose was to review their groin lymphatic fistulae over the last ten years to assess their approach and determine long-term outcome. Forty-five patients during the past ten years had an identified lymphatic fistula following vascular reconstruction involving the femoral artery. Sixty-seven per cent had underlying prosthetic grafts at risk. Twenty-three patients were man aged conservatively (bed rest, pressure dressing, antibiotics) with an average of thirteen days of lymphatic fistula and all resolved. In 22 patients the lymphatic fistula was stopped by exploration and simple closure after an average of fourteen days. The average length of stay after vascular surgery was sixteen days in patients treated conservatively, and twenty-four days in those treated surgically. There were 3 groin infections in the group treated conservatively. Follow-up of all patients averaged fifty-three months (range three to one hundred thirty-one months), and there was no evidence of false aneurysm formation or graft infec tion. Both conservative and operative approaches are effective in the management of the lymphatic leak, and the decision between the two methods of treatment depends upon drainage volume and duration.

The Management of Chronic Venous Ulcers and the Benefit of Subfascial Endoscopic Perforator Vein Surgery

Elastic compression is the primary treatment modality of venous ulcers. Local ulcer treatment is important to enhance granulation and prevent or treat infection, while surgical treatment is aimed at correcting the underlying venous stasis and ambulatory venous hypertension. This debate reviews the pros and cons of surgical treatment for venous incompetence and discusses current evidence to support the use of subfascial endoscopic perforator vein surgery (SEPS). Ablation of superficial reflux with high ligation and stripping of the incompetent saphenous vein, done together with avulsion of varicose veins, remains the main surgical treatment of chronic venous insufficiency. Level 1 evidence of clinical and hemodynamic improvement directly related to interruption of incompetent perforators is currently not available. The North American SEPS registry experience and reports from larger centers, however, provide data on rapid ulcer healing, low morbidity, and decreased wound complications from endoscopic perfor...