Jacob G. Robison

Endovascular treatment of abdominal aortic aneurysms: a review.

Abstract Abdominal aortic aneurysm (AAA) is a relatively common disease among the elderly population and may be present in up to 5.9 % of the population aged 80 years. Abdominal aortic aneurysm more than 5 cm in diameter are more prone to rupture, with a significant mortality rate. Conventional surgical treatment is quite effective in the lower surgical risk population; however, in the population with a higher risk level the mortality and morbidity significantly increase. The development of less invasive techniques to treat AAA derived from the necessity to reduce the morbidity and mortality. The development of the endovascular endoprostheses was a significant landmark in the management of those patients with AAA, particularly the ones with increased risk. Although the stent-graft technology is still in its infancy, a large amount of information is available and an attempt to summarize this experience is presented herein. An extensive review of the stent-graft technology is presented, including variations in design and classification of the several systems available. Technical aspects of the use of endovascular prostheses are presented, as well as the most recent outcome information available. The problems of endoleaks is discussed and the techniques for treatment and outcomes presented. Finally, a summary of specific information on most of the devices available is presented.

Popliteal artery pseudoaneurysm following arthroscopy

An 18-year-old male presented with left foot ischemia secondary to emboli from a pseudoaneurysm of the left popliteal artery. His past history was significant only for two arthroscopies of his left knee. After evaluation, the patient was successfully treated with obliteration of the aneurysm and a reverse saphenous vein bypass graft.

Detection of occult breast cancer micrometastases in axillary lymph nodes using a multimarker reverse transcriptase-polymerase chain reaction panel ☆

BACKGROUND Axillary lymph node status in breast cancer patients remains the single most important predictor of outcomes. Current methods of histopathologic analysis may be inadequate because 30% of node-negative patients recur. The purpose of this study was to test the hypothesis that a multigene reverse transcriptase-polymerase chain reaction (RT-PCR) panel provides a more sensitive method to detect axillary lymph node metastases than routine pathologic examination. STUDY DESIGN Sixty-one consecutive breast cancer patients were evaluated, with nine normal control patients. Nodes > 1 cm were bisected for histopathologic and RT-PCR analysis. Nodal tissue was homogenized, and total RNA was converted into cDNA with reverse transcriptase. Reverse transcriptase-polymerase chain reaction analysis was performed with primers specific for keratin-19, c-myc, prolactin inducible protein (PIP), and beta-actin using ethidium bromide gel electrophoresis. Reverse transcriptase-polymerase chain reaction positive/ pathology negative axillary lymph nodes were reevaluated using step sectioning and immunohistochemical staining. RESULTS Thirty-seven patients had pathologically negative axillary lymph nodes, of which 15 (40%) were positive by RT-PCR analysis. Two RT-PCR negative results (one probably from tissue processing error and the other secondary to sampling error) among the 24 histologically positive specimens were detected (8%). The number of patients in each pathologic stage was 26 patients in stage I; 18, stage IIA; 7, stage IIB; 7, stage IIIA; 3, stage IIIB; and 0 patients in stage IV. By RT-PCR staging, 8 of 26 patients went from stage I to IIA (30%), and 7 of 18 from stage IIA to IIB (39%). Of the RT-PCR positive individuals who were stage I by pathologic analysis, 100% were found to be c-myc positive, 0% keratin-19 positive, and 0% PIP positive; for stage IIIB patients these markers were 50%, 100%, and 100% respectively. Additionally, an increasing number of positive markers per specimen appeared to correlate with larger primary tumor size (p < 0.01) and decreased predicted 5-year survival (r = 0.950, p < 0.002). CONCLUSIONS Multimarker RT-PCR analysis appears to be a readily available and highly sensitive method for the detection of axillary lymph node micrometastases. Longterm followup of RT-PCR positive patients will be required to determine its clinical relevance. If validated as a predictor of disease recurrence, this method would provide a powerful complement to routine histopathologic analysis of axillary lymph nodes.

Limitations of peroneal artery bypass grafting for limb salvage

PURPOSE The purpose of this study was to compare the results of peroneal bypass grafting for limb salvage with the results of other tibial and pedal bypass grafts performed concurrently. METHODS Thirty-four peroneal bypass grafts with autologous vein were performed for limb salvage between September 1986 and June 1992. These constituted 18% of an overall experience of 194 tibial or pedal bypasses performed during that time. Preoperative and intraoperative arteriograms were reviewed to identify anatomic characteristics associated with successful limb salvage. RESULTS Secondary patency rates for peroneal bypass grafts (70%) compared with the other tibial and pedal bypass grafts (65%) did not differ significantly at 48 months by life-table analysis. Limb salvage achieved by peroneal artery bypass grafting was significantly worse (55%) than that achieved by the remaining tibial and pedal bypasses (67%) at 48 months. Limb salvage was 33% at 7 months for those undergoing peroneal artery bypass grafting as opposed to 57% at 48 months for patients undergoing other tibial or pedal revascularizations with tissue necrosis. Four anatomic features were identified that were associated with failure after peroneal artery bypass grafting. These were peroneal length less than 10 cm (p = 0.012), peroneal artery diameter less than 2 mm (p = 0.035), absence of arteriographically demonstrated collaterals perfusing the foot (p = 0.0001), and little or no visualization of the pedal arch (p = 0.008). CONCLUSIONS Although successful grafts may avoid amputation in carefully selected cases, alternatives to peroneal artery bypass grafting should be considered when less than favorable anatomic conditions are encountered, particularly in the presence of forefoot tissue necrosis.

Abdominal Aortic Aneurysm Treatment: Preliminary Results with the Talent Stent-Graft System

PURPOSE To evaluate the treatment of abdominal aortic aneurysm (AAA) with use of the endoluminal Talent stent-graft (TSG). PATIENTS AND METHODS In 10 men, AAA treatment was attempted with use of the TSG. All patients presented significant surgical risk, with chronic obstructive pulmonary disease and coronary arteriopathy. The mean age was 65.5 years (range, 57-82 years). The mean proximal neck diameter was 25.8 mm (range, 21.6-34 mm). Five of the TSGs were straight tubes and five were bifurcated systems. The main body of the TSG is made of a polyester graft material mounted on a self-expandable nitinol frame. The bifurcated system uses polytetrafluoroethylene (PTFE) material for the legs and extensions mounted on a self-expandable nitinol frame. The bifurcated grafts used a 22 to 27-F introducer and the extensions, a 18-F introducer through a surgical cutdown technique. RESULTS The TSG system was successfully implanted in nine patients and failed in one because of dislodgment after deployment, which required conversion to surgery. Four leaks occurred initially. One was sealed off with balloon dilation at the end of the procedure, one leak was treated with an additional extension, another leak disappeared spontaneously in 30 days, and the other leak required embolization 4 weeks after discharge. Seven patients were discharged on the third day after the procedure, and two patients were discharged at 1 and 2 weeks, respectively. Blood transfusion was necessary in three patients because of hematoma at the incision site in two patients, which required surgical revision for hemostasis, and because of transoperative bleeding in one patient. Follow-up time ranged from 2 to 15 months. The only death occurred 5 days postoperatively as a consequence of ischemic colitis and multisystem organ failure in the only patient who required surgery. CONCLUSION Treatment of AAA with the TSG system is effective for aneurysm exclusion. This device seems to provide a good alternative to surgery in patients who are otherwise considered to be at high risk for complications after direct surgical repair, but it is not without risk of complications.

Placement of Inferior Vena Cava Filters in Bariatric Surgical Patients – Possible Indications and Technical Considerations

Background: Surgical treatment of the morbidly obese has assumed an increasingly important role in both the academic and community setting, while postoperative pulmonary embolism remains a devastating complication. Since the overall incidence remains low, the role for vena cava filter placement in this group is not yet well defined. In addition, the technical challenges and techniques for insertion have not been well-described. We present our experience with filter placment among patients with gastric bypass and the evolution of technique to facilitate safe placement in this group. Methods: From 1995 to August 2003, 586 patients underwent gastric bypass for morbid obesity. Review of registries and records from this period was accomplished to identify patients at MUSC who underwent both the gastric bypass and placement of an inferior vena cava filter. 12 patients were identified by this method. Results: Technical challenges with venous access and imaging are described. 6 patients were identified as potential high risk for thromboembolic complications and had a filter placed preoperatively with a mean postoperative stay of 5.3 days. The 6 patients who required filter placement in the postoperative period as part of the management of postoperative complications had a mean hospital stay of 24.5 days. There were no long-term complications associated with filter placement at a mean follow-up interval of 19 months. Conclusion: Inferior vena cava filter placement is not only feasible and safe for the morbidly obese individual undergoing gastric bypass, but should be strongly considered for patients with risk factors for thromboembolic complications or who experience postoperative complications requiring ICU stay or prolonged immobility.

Racial differences in operation for peripheral vascular disease: results of a population-based study

Operation for non-coronary atherosclerotic peripheral vascular occlusive disease may vary among race and gender groups. Using a state-wide registry, the authors identified all operations performed for infrarenal peripheral vascular disease over a 12-month period in a single south-eastern state. Procedures performed included reconstruction for aortoiliac (n=641) and infrainguinal (n=1129) disease and major amputation (n=1077). The incidence for patients over age 50 was calculated using census data. Operation for aortoiliac disease was significantly more likely for white patients (relative risk 3.79, 95% C.I. 2.84-5.15), but less likely for infrainguinal peripheral vascular disease (relative risk 0.64, 95% C.I. 0.56-0.73) and amputation (relative risk 0.17, 95% C.I. 0.15-0.19). Trends toward lower operative mortality in blacks with aortoiliac disease (10.6% versus 12.0%), PVD (3.2% versus 3.5%), and amputation (5.5 versus 8.7%) failed to attain statistical significance. Patient race was associated with the type and location of operation performed for peripheral vascular disease.

Distal wound complications following pedal bypass: analysis of risk factors.

Wound complications of the pedal incision continue to compromise successful limb salvage following aggressive revascularization. Significant distal wound disruption occurred in 14 of 142 (9;8%) patients undergoing pedal bypass with autogenous vein for limb salvage between 1986 and 1993. One hundred forty-two pedal bypass procedures were performed for rest pain in 66 patients and tissue necrosis in 76. Among the 86 men and 56 women, 76% were diabetic and 73% were black. All but eight patients had a history of diabetes and/or tobacco use. Eight wounds were successfully managed with maintenance of patent grafts from 5 to 57 months. Exposure of a patent graft precipitated amputation in three patients, as did graft occlusion in an additional patient. One graft was salvaged by revision to the peroneal artery and one was covered by a local bipedicled flap. Multiple regression analysis identified three factors associated with wound complications at the pedal incision site: diabetes mellitus (p=0.03), age >70 years (p=0.03), and rest pain (p=0.05). Ancillary techniques (“pie-crusting”) to reduce skin tension resulted in no distal wound problems among 15 patients considered to be at greatest risk for wound breakdown. Attention to technique of distal graft tunneling, a wound closure that reduces tension, and control of swelling by avoiding dependency on and use of gentle elastic compression assume crucial importance in minimizing pedal wound complications following pedal bypass.

Protamine use during peripheral vascular surgery: A prospective randomized trial

PURPOSE One hundred twenty patients undergoing aortic reconstruction (40), infrainguinal bypass (49), and carotid endarterectomy (31) were prospectively enrolled into a double-blind randomized trial to investigate the utility of routine heparin reversal with protamine. METHODS All patients underwent systemic heparinization with 90 U/kg body weight during operation and after revascularization were randomized to receive either protamine or saline solution for heparin reversal. Blood loss was measured throughout the surgical procedure, and indexes of coagulation and the requirement for blood and blood products were documented during operation and the first 24 hours after operation. RESULTS Plasma heparin concentration, partial thromboplastin time, and activated clotting time were significantly higher (p < 0.05) in those receiving saline solution at 20 minutes and 1 hour after administration. Total surgical blood loss was not significantly different between study groups. No significant differences were found in blood product requirement, intravenous fluid administered, hematocrit, or wound hematomas between groups at 24 hours. In addition, no difference was seen in the surgeons subjective intraoperative assessment of hemostasis after administration of either study drug. Furthermore, after study drug administration protamine was associated with a deleterious effect on subsequent intraoperative blood loss (318 +/- 33 ml vs 195 +/- 18 ml, p < 0.05). CONCLUSIONS Although protamine effectively reverses heparin anticoagulation, its routine use after elective peripheral vascular surgical reconstruction does not appear to provide any clinical benefit.

Diabetes mellitus is the major risk factor for African Americans who undergo peripheral bypass graft operation.

OBJECTIVE African Americans, especially African American women, have a greater risk of lower extremity ischemia that necessitates an infrainguinal bypass graft operation and amputation. Because the prevalence of diabetes mellitus is proportionally greater in this ethnic/racial group, the relative contribution of diabetes was compared with other potential risk factors. METHODS This study was designed as a retrospective case control study at the University and Veterans Hospitals. In a 5-year period, 764 consecutive patients who required infrainguinal revascularizations were compared with a statewide population that was described by the 1995 Behavior Risk Factor Surveillance System database. The main outcome measure was the requirement for infrainguinal revascularization. RESULTS Diabetes mellitus was more common among African American women who underwent bypass graft operation (70%; odds ratio [OR], 24.9; 95% confidence interval [CI], 20.3 to 30.4) than African American men (46%; OR, 11.6; 95% CI, 8.9 to 15.2), white women (49%; OR, 15.9; 95% CI, 13.0 to 19.5), or white men (42%; OR, 14.8; 95% CI, 12.5 to 17.4). Overall, bypass graft operation was associated more strongly with diabetes mellitus for all groups (OR, 15.7; 95% CI, 13.5 to 18. 3) than with smoking (OR, 4.5; 95% CI, 3.8 to 5.2) or hypertension (OR, 4.6; 95% CI, 4.0 to 5.3). Life-table analysis revealed limb salvage to be worse at 3 years among African American patients (64% vs 75%; P <.005) despite similar primary and cumulative secondary graft patency rates. CONCLUSION Diabetes mellitus is the dominant risk factor that contributes to the need for bypass graft operation, especially among African American women. A greater prevalence of diabetes mellitus may account for the higher incidence of tissue necrosis and the increased requirement for distal bypass grafting and may contribute to the reduction in long-term limb salvage that was observed with these women.