Evaluation of sex differences in relative dilatation of thoracic aortic aneurysms.

OBJECTIVES: Treatment recommendations based on thoracic aortic aneurysm (TAA) diameter (D) ignore differences in proportional dilatation between patients of different body habitus and sex. This study's goal is to compare TAA diameters between sexes as a function of relative aortic size as determined by aortic size index (ASI). METHODS: This is a retrospective review of all TAA's treated between 2003 and 2008. ASI was calculated for each patient, which considers aneurysm diameter, patient's height and weight. Values for males and females were plotted separately (TAA diameter vs ASI) and the resulting linear regression equations permitted comparison of proportional dilatation between sexes. RESULTS: In 40 patients (25 males, 15 females) mean TAA diameter did not differ between sexes (6.56 +/- 0.99 vs 7.03 +/- 1.14, P = 0.18), while ASI was larger in females than males (4.21 +/- 0.85 vs 3.24 +/- 0.63, P = 0.0003). Values for ruptured and intact aneurysms did not differ. Linear regression analysis permitted comparison of TAA diameter with ASI between sexes resulting in the following equation: D(Female) = 0.91D(Male) - 0.49. This correlates a 6 cm TAA in a male with a 4.97 cm TAA in a female. CONCLUSIONS: TAA of equal diameter represent a larger proportional dilatation in females compared to males. This could influence repair thresholds that are historically diameter based.

Intestinal mucosal permeability to 51Cr-ethylenediaminetetraacetic acid is increased after bilateral lower extremity ischemia-reperfusion in the rat.

BACKGROUND: Despite successful revascularization of ischemic extremities, multiorgan dysfunction syndrome develops in some patients. Mechanisms responsible for this are not known; however, the gastrointestinal tract has been implicated as a possible mediator. Our objective was to demonstrate increased intestinal mucosal permeability after bilateral hindlimb ischemia-reperfusion (I-R) in a rodent model. METHODS: Sixteen male Wistar rats were randomized either to 4 hours of bilateral hindlimb tourniquet ischemia and 24 hours of reperfusion (n = 8) or control groups (n = 8). The animals received 10 MuCi 51Cr-ethylenediaminetetraacetic acid (EDTA) by gavage, and excretion was measured in urine collected every 8 hours in 16 animals and every 4 hours in 8 animals. Arterial blood pressure was monitored continuously. Intravenous normal saline solution (3 ml/hr) with fentanyl (2 microgram/100 gm/hr) was continuously administered. Immediately before death complete blood count and levels of arterial lactate, creatinine, and urea were obtained. Mesenteric lymph nodes were harvested from the ileocecal region and cultured. Distal small bowel and proximal colon were preserved for histologic analysis. An additional 11 rats, six experimental and five control, were evaluated for mesenteric lymph node cultures only. RESULTS: Urinary excretion of 51Cr-EDTA was significantly greater in the I-R group between 0 and 8 hours (p < 0.02) and 8 to 16 hours (p < 0.0002) of reperfusion. This increase occurred as early as 4 to 8 hours of reperfusion (p < 0.0001). Urine volume in the I-R group was significantly reduced during 0 to 4 hours of reperfusion (p < 0.002). Hemoglobin and lactate level were significantly different in the I-R group. Leukocyte and platelet counts, levels of creatinine and urea, and colony counts from mesenteric lymph nodes were similar in I-R and control groups. Blinded histologic analysis of bowel segments did not reveal morphologic differences. CONCLUSIONS: Bilateral hindlimb I-R produces remote intestinal mucosal injury shown by significantly increased permeability to 51Cr-EDTA. Such increased mucosal permeability may be important in the development of multiorgan dysfunction syndrome in patients who sustain lower extremity I-R injury.

Cervical node metastasis of occult origin.

This study reviewed a 12 year experience with 132 patients who were treated for metastatic carcinoma of the cervical lymph nodes with no apparent primary tumor. Using radical neck dissection as the main treatment modality, a 5 year survival of 50 percent was achieved in 79 patients with epidermoid carcinoma. Survival varied significantly depending on the extent of the tumor in the neck. It was 74 percent in those with stage N1 disease compared with 41 percent in patients with N2 or N3 disease. Recurrence in the neck, the major reason for treatment failure, can probably be reduced by more aggressive use of adjunctive radiotherapy. Primary tumors were identified after therapy in only 15 percent of these patients, and this appeared to have relatively little impact on the outcome. Irradiation and chemotherapy were the preferred treatment modalities in 29 patients with metastatic adenocarcinoma of occult origin. All but one patient died within 29 months. A 53 percent 5 year survival was achieved in 13 patients with anaplastic or undifferentiated carcinoma. Radical neck dissection was employed in 11 patients with melanoma. No primary tumor was ever identified in this group and only one patient remained alive and well after 5 years.

A database coding system for vascular procedures.

A coding system was developed to overcome the difficulties encountered in data registry and retrieval from a national audit. In vascular surgery operations are frequently combined, and neither the OHIP fee schedule of codes (Ontario, Canada) nor the ICD-9 system provides sufficient detail for most vascular surgeons to retrieve information for long-term follow-up. However, some wish to record minimal data on their operative procedures. A numeric classification system was developed. A five-digit number is used, the first two digits classifying the operative procedure and anatomic details. Two decimal digits code the classification of operation (e.g., aortic aneurysm, tube graft, aortoiliac, or aortobifemoral) and the final digit may be used as a modifier. "Holes" in the numeric system allow for new operations to be added as they develop. Codes are stored in a database with the following fields: 1) codes; 2) description of operation; 3) translation. The translation field may be modified to permit translation of any existing databases into the system. This database has been distributed with a data registry program free of charge to vascular surgeons in Canada to allow nationwide registry of vascular surgery patients. A numeric code eliminates spelling and abbreviation errors, and can be sufficiently broad-based to allow all surgeons to participate in a nationwide audit.

Primary aorto/iliac-enteric fistula-report of 6 new cases.

The management of patients with vascular-enteric fistulas remains a challenging diagnostic and therapeutic problem for the vascular surgeon. Although fortunately quite a rare cause of gastrointestinal bleeding, reported mortality and amputation rates are very high. Fistulas between major vascular structures and the gastrointestinal tract are classified as either primary or secondary. Primary fistulas occur most commonly between an aortic aneurysm and the distal duodenum, while secondary fistulas occur following erosion of prosthetic material into the bowel following aortic reconstruction. The authors report 6 new cases of primary aortoenteric fistula: A malignant aortoenteric fistula in a patient with advanced metastatic squamous cell carcinoma involving the infrarenal aorta and duodenum, 4 cases of primary aortoenteric fistulas in patients with abdominal aortic aneurysms, and 1 iliac-enteric fistula secondary to a common iliac aneurysm. The diagnosis is often difficult to make, and although it was considered in 4 patients preoperatively, the diagnosis was not made until the time of laparotomy in all of these patients. Three patients were treated with an in-situ vascular graft, 2 others had the distal abdominal aorta oversewn and axillobilateral femoral bypass performed, and in the case involving the malignancy, the patient underwent primary aortic repair owing to the extent of the tumor process prohibiting aortic reconstruction. Three patients had primary closure of the intestine performed, and 3 required bowel resection and primary anastomosis. The overall 30-day mortality rate was 50% as 3 patients died in the early postoperative period and the remaining 3 patients survived to be discharged from hospital. One patient (17%) required bilateral above-knee amputations. Treatment of patients with vascular-enteric fistulas is a difficult problem, often associated with delayed diagnosis and high morbidity and mortality rates. Successful surgical management can be achieved with primary closure of the intestinal tract and an in-situ vascular graft or extraanatomic bypass.

Infected arterial grafts: clinical manifestations and surgical management.

The clinical manifestations and results of management in twenty-five patients treated for infected vascular grafts are reviewed. The overall incidence of infection in this series of prosthetic grafts is 1.4%. Staphylococcus aureus was found to be the single most common infecting organism and multiple organisms were found in nine patients. Therapy was divided into three methods of management: local therapy alone resulted in a mortality of 45% and an amputation rate of 36.3%; partial graft excision resulted in a mortality of 20% and an amputation rate of 60%; total graft excision resulted in a mortality of 22% and an amputation rate of 22% as well. All amputations were above-knee amputations and the most common cause of death was continuing sepsis. The overall mortality of 32% and a loss of limb rate of 44% are testimony to the serious nature of this problem.

Are simultaneous aortic reconstruction and renal revascularization safe and effective?

Between 1983 and 1989, 40 patients with uncontrollable hypertension underwent renal revascularization. Of these, 21 patients had simultaneous aortic and renal revascularization. Eleven of the 21 patients (52.4%) had renal insufficiency with a mean creatinine clearance of 0.61 +/- 0.23 ml/sec. Eleven patients had an aortic aneurysm; the remaining 10 patients had aortic occlusive disease of varying severity. Aortic reconstruction was done with either a straight (8 patients) or bifurcated (13 patients) Dacron graft. Renal revascularization was accomplished with either bypass (11 patients) or transaortic endarterectomy (10 patients). One patient died postoperatively secondary to myocardial infarction (operative mortality rate of 4.7%). Among the 11 patients with renal insufficiency the mean creatinine clearance of 0.61 +/- 0.23 ml/sec preoperatively improved to 0.94 +/- 0.30 ml/sec postoperatively (p less than 0.01). In the follow-up period extending to 78 months (mean 39.1 months), one late death occurred. There were no instances of worsening hypertension or deterioration in renal function. Contrary to some previous reports, our results indicate that severe aorto-renal atherosclerosis can be managed with simultaneous aortic reconstruction and renal revascularization at an acceptably low operative risk. In addition, a significant and persisting benefit in both hypertension control and renal dysfunction can be expected after surgery.

Intraoperative thrombolytic therapy as a treatment of small vessel thrombosis: an experimental study.

OBJECTIVE: This paper studies the effect of three doses of Streptokinase infused intra-operatively into an animal model of small vessel thrombosis. EXPERIMENTAL DESIGN: This is a controlled trial of intraoperative infusion of thrombolytic agent into a thrombosed arterial segment compared to no infusion into the contralateral limb. EXPERIMENTAL SUBJECTS: 19 New Zealand White rabbits were stratified into 3 groups. INTERVENTIONS: Thrombosis was achieved by infusing a mixture of topical thrombin and autologous blood into individual iliac arteries of the New Zealand white rabbit. A randomly selected hind limb had an infusion of one of three doses of streptokinase (A = 2,500u; B = 5,000u; C = 10,000u) in saline over 20 minute period. Preinfusion and post infusion angiography was performed. MEASUREMENTS: Angiograms were ranked by a radiologist blinded to the side of infusion and clotting parameters were assessed. RESULTS: All limbs at all doses of streptokinase infusion (SK) showed significant clot lysis when compared to the non-infused limb(C). The percentage of improved segments is as follows: iliac: SK = 100%, C = 79%; femoral SK = 79%, C = 32%; tibial SK = 52%, C = 5%. Although there was an elevation in clotting time and a reduction in fibrinogen, levels remained within normal limits. CONCLUSIONS: Streptokinase infused directly into thrombus in arteries even in low doses significantly enhances thrombolysis of vessels which are too small to be cleared by mechanical means. No significant systemic complications were encountered.

Establishing an endovascular abdominal aortic program--decisions, decisions, decisions: The London Health Sciences Centre experience.

The endovascular repair of abdominal or thoracic aortic aneurysms is an alternative approach to conventional repair in the compromised patient. Although the long-term efficacy of these procedures has yet to be proved, there is growing interest among vascular surgeons and interventional radiologists throughout North America and Europe in the more frequent use of this technique. Starting an endovascular program necessitates extensive cooperation of the interdisciplinary vascular team. Decisions regarding patient selection, equipment, supplies, staff education, and the location of the procedure must be based on sound principles. This article demonstrates how a program can be planned, implemented, and evaluated by the use of a "decision tree." The experience of the London Health Sciences Centre will be used as a benchmark in the discussion of relative merits of branch points in program development. The article gives persons contemplating a program a structured process in decision making to avoid potential pitfalls.

Peripheral aneurysms.

Aneurysms of the peripheral arteries usually involve the femoral or popliteal regions. Although not as common as abdominal aortic aneurysms, they carry a significant morbidity if left untreated. Rupture is a rare complication, but embolization or thrombosis may frequently threaten the viability of the limb. Elective repair of peripheral aneurysms will prevent complications of these lesions. This paper outlines the history, diagnosis, and treatment of peripheral aneurysms with emphasis on nursing care.

The use of arm vein as an alternative conduit for lower-extremity bypass.

A 4-year retrospective review of all cases utilizing arm vein for lower-extremity bypass was undertaken. Thirty-six cases were reviewed. The patients had portions of the basilic or cephalic arm veins, or both, harvested and used as a bypass for limb salvage. Composite grafts using a portion of arm vein were excluded. Information on demographics, risk factors, vascular surgical history, presenting signs and symptoms, surgical complications, patient comfort (arm vs. leg pain), and patency rates was studied. We found that all patients were initially seen with claudication or rest pain, that 22% had gangrenous changes, that there was a male dominance (75%), and that all had previous coronary artery bypass grafts or lower-extremity bypass. Limb salvage rate was 85% at 4 years. Primary patency rate was 71% at 4 years. We conclude that arm vein is a useful and durable conduit for bypass. Patient acceptance and comfort is high.

Management of venous stasis ulcer: long-term follow-up.

In this study 112 patients (122 lower limbs) who had chronic venous stasis ulceration refractory to conservative management were treated surgically. Subfascial ligation was performed on 118 limbs and the long saphenous vein was removed in 4. Complications consisted of postoperative thrombophlebitis (2%), wound infection (2%) and wound infection with ulcer necrosis (1.5%). These all responded to conservative management. Follow-up (mean 7.9 years, median 11 years) showed a good or excellent result in 82% of cases, with healing of the ulcer and no ulcer recurrence despite significant noncompliance with support stockings. This paper is a long-term follow-up study of a surgical procedure for chronic venous stasis ulcers. The authors believe that the 82% good and excellent results may indicate that surgical intervention for refractory venous ulcers is a worthwhile procedure, providing potentially satisfactory long-term results.

Myocardial and circulatory performance during the ischemic phase of superior mesenteric artery occlusion.

OBJECTIVE: To investigate myocardial and circulatory parameters during the acute ischemic phase of mesenteric artery occlusion. DESIGN: A prospective, randomized, control trial. SUBJECTS: Twelve, adult, mongrel dogs. INTERVENTIONS: In seven dogs the superior mesenteric artery was occluded with two silk ligatures (experimental group). In five dogs the ligatures were not tied (control group). Measurements were made during 7 hours of occlusion. MAIN OUTCOME MEASURES: Myocardial performance and circulatory performance. RESULTS: There were significant (p < 0.05) reductions in arterial blood pressure, mean pulmonary artery pressure, diastolic pulmonary artery pressure and cardiac index in dogs exposed to intestinal ischemia compared with the control dogs. No differences were identified in ventricular performance, stroke volume index or peripheral vascular resistance index. CONCLUSIONS: Early cardiac and central circulatory changes in massive intestinal ischemia are due to intravascular hypovolemia. Sepsis and myocardial depressant factors were not found to be a cause of death.

Epithelial-myoepithelial carcinoma of the salivary gland.

Epithelial-myoepithelial carcinoma of salivary gland is a rare tumor only recently described in the English language literature. This paper adds four new cases to the 30 which have previously been reported. The clinical presentation of this unusual neoplasm is documented in the accompanying case reports and the appropriate surgical management outlined. Follow-up ranges from six months to 12 years. The histopathological characteristics of this interesting tumor, in particular its classical biphasic cellular appearance, are described in detail both by light and electron microscopy. On the basis of histologic appearance and biological behavior, the authors postulate that epithelial-myoepithelial carcinoma is an uncommon variant of adenoid cystic carcinoma.

Endovascular repair of abdominal aortic aneurysm with coexisting renal allograft: case report and literature review.

The coexistence of an abdominal aortic aneurysm (AAA) and a pelvic renal allograft is a unique clinical situation. Because of the increased susceptibility of the transplant kidney to ischemic injury, various approaches have been developed to minimize allograft ischemia during open aneurysm repair. Endovascular techniques have the potential advantage in this situation of greatly diminishing renal ischemia time. To our knowledge, this approach has not been reported in this situation. We report a case of a 61-year-old male with a 7.0-cm AAA and a functioning right pelvic transplant kidney. There was an adequate aneurysm neck below the level of the superior mesenteric artery with occluded renal arteries. Successful endovascular repair of the aneurysm was achieved using a bifurcated graft and bilateral iliac extensions. Perfusion to the renal allograft was maintained throughout the procedure except for short periods when the graft was expanded with a balloon. Short-term follow-up reveals successful aneurysm exclusion and no deterioration in renal function. This exciting new approach to this challenging clinical problem is reviewed along with other methods of minimizing renal allograft ischemia.

Arteritis due to Salmonella with aneurysm formation: two cases.

Although arterial infection due to Salmonella is rare, it remains one of the most common causes of primary mycotic aneurysms. The presentation is one of sepsis, cultures positive for Salmonella and rapid expansion or rupture of the aneurysm. The authors' experience at Victoria Hospital, London, Ont., includes two cases of aneurysms infected with Salmonella--one aneurysm of the aorta and the other of the common femoral artery. Both patients were treated by excision of the aneurysm, extra-anatomic reconstruction in an area remote from the infected field and long-term administration of appropriate antibiotics. One patient was alive and well 36 months after resection. The other died of multiple organ failure 10 days after resection. From a review of the English and French literature since 1948, 64 cases of abdominal aortic aneurysms infected with Salmonella were found; half of the patients survived the perioperative period. The diagnosis of mycotic aneurysm must be considered in any patient with an aneurysm and culture specimens positive for Salmonella. The authors favour wide débridement of the infected aneurysm with extra-anatomic reconstruction. This view is supported by a review of the literature. The appropriate antibiotic therapy is bactericidal rather than bacteriostatic.

The role of descending venography in the management of patients with chronic venous disease of the lower extremity.

The purpose of this paper is to evaluate the efficacy and clinical information obtained from the authors' first 17 consecutive descending venograms. All 17 patients had chronic venous disease refractory to standard conservative and surgical measures. The standard classification of valvular insufficiency was used in evaluating these venograms. There were no deaths, slight morbidity and minimal patient discomfort. In 16 patients meaningful clinical information was derived from the venograms, with 7 patients having deep venous valvular surgery. Descending venography will demonstrate the site of incompetent valves and estimate the degree of reflux. This test is necessary before anticipated reconstruction of deep vein valves.

Healing of microvascular anastomoses. A comparative study using normal and irradiated recipient vessels for experimental free flaps in rabbits.

A comparative study was undertaken to evaluate the possible effect of previous radiotherapy on the healing of subsequently performed microvascular anastomoses between irradiated recipient vessels and normal flap vessels in rabbits. Radiotherapy was given preoperatively to a single anterior neck field using a Cobalt 60 unit, 1.25 MeV, SSD 80 cm in a fractionated dose corresponding to 5,000 rad/5 weeks. An experimental model using paired data was established using two epigastric free island flaps in each animal: one anastomosed to the irradiated vessels (carotid artery and jugular vein) and the other anastomosed to the normal opposite femoral vessels. Results did not show any marked difference in the healing pattern during the first 3-week period postoperatively except for a higher rate of thrombosis, when irradiated recipient vessels were used in end-to-end anastomoses, while no difference in healing pattern or rate of thrombosis were found using telescoped arterial anastomoses.