Popliteal artery aneurysms: is endovascular reconstruction durable?

PURPOSE: To describe an endovascular method of performing femoropopliteal in situ saphenous vein (SV) bypass and popliteal artery aneurysm (PAA) embolization. METHODS: Twenty-two patients underwent PAA operations. Twelve patients had conventional SV bypasses with PAA proximal and distal ligation, whereas 10 underwent PAA embolization and an endovascular in situ SV bypass (EISB). The endovascular procedure was performed using an angioscopically guided side branch coil occlusion system. The PAAs were coil embolized under fluoroscopic surveillance. RESULTS: No deaths or wound complications occurred in the EISB group. The mean hospital length of stay (LOS) was 2.1 days. Seven EISB procedures were performed through 2 incisions, whereas 3 operations required an additional incision. One graft occluded at 3 months. All PAAs remained occluded by color-flow ultrasonography at follow-up ranging from 4 to 23 months (mean 13.6); cumulative primary patency was 89%. In the conventional bypass group, no deaths occurred, but 3 (25%) patients had wound complications. The mean LOS was 6.2 days, and 1 graft occluded, giving an 86% cumulative primary patency at 42 months. CONCLUSIONS: This minimally invasive technique obviates an extensive incision to harvest the SV and ligate the PAA proximally and distally. If long-term endovascular bypass graft patency and PAA occlusion rates prove to be similar to open operative results, the benefits of reduced wound complications, decreased hospital LOS, and increased health care savings support further investigation of this endovascular approach for the treatment of PAA.

Cryopreserved femoral vein grafts for difficult hemodialysis access.

Improved survival of patients with renal failure has led to the need for complex angioaccess procedures. The use of cryopreserved femoral vein for angioaccess when prosthetic arteriovenous grafts (AVG) could not be placed, owing to infection or the loss of conventional angioaccess sites from multiple AVG failures, was prospectively evaluated. Forty-eight cryopreserved femoral vein AVGs were placed in 44 patients. Thirty-eight (82%) of the cryopreserved femoral vein AVGs were placed for infection, whereas the other 10 (18%) were placed for multiple graft failures with compromised venous outflow. Even with implantation of the cryoveins into infected patients, there were no cryopreserved femoral vein AVG infections. The 1-year primary graft patency rate was 49% and the secondary graft patency rate was 75%. During the same time interval, 68 prosthetic brachial artery-to-axillary vein AVGs were placed. The 1-year primary and secondary patency rates for the prosthetic AVGs were 65 and 78%, respectively. In this study the overall patency rate of the cryopreserved femoral vein AVGs was similar to that for the PTFE AVGs (p = 0.519). In conclusion, the cryopreserved femoral vein proved useful in difficult angioaccess cases. The lack of infection after cryovein implantation around an infected area shows promise for salvaging an angioaccess site that would otherwise have been abandoned.

Comparison between the transabdominal and retroperitoneal approaches for aortic reconstruction in patients at high risk.

PURPOSE: The purpose of this study was to compare the transabdominal approach with the retroperitoneal approach for elective aortic reconstruction in the patient who is at high risk. METHODS: From January 1992 through January 1997, 148 patients underwent aortic operations: 92 of the patients were classified as American Society of Anesthesia (ASA) class IV. Forty-four operations on the patients of ASA class IV were performed with the transabdominal approach (25 for abdominal aortic aneurysms and 19 for aortoiliac occlusive disease), and 48 operations were performed with the retroperitoneal approach (27 for abdominal aortic aneurysms and 21 for aortoiliac occlusive disease). There were no significant differences between the groups for comorbid risk factors or perioperative care. RESULTS: Among the patients of ASA class IV, eight (8.7%) died after operation (retroperitoneal, 3 [6.26%]; transabdominal, 5 [11.3%]; P =.5). There was no difference between groups in the number of pulmonary complications (retroperitoneal, 23 [47.9%]; transabdominal, 19 [43.2%]; P =.7) or in the development of incisional hernias (retroperitoneal, 6 [12.5%]; transabdominal, 5 [11.3%]; P =.5). The retroperitoneal approach was associated with a significant reduction in cardiac complications (retroperitoneal, 6 [12.5%]; transabdominal, 10 [22.7%]; P =.004) and in gastrointestinal complications (retroperitoneal, 5 [8.3%]; transabdominal, 15 [34.1%]). Operative time was significantly longer in the retroperitoneal group (retroperitoneal, 3.35 hours; transabdominal, 2.98 hours; P =.006), as was blood loss (retroperitoneal, 803 mL; transabdominal, 647 mL; P =.012). The patients in the retroperitoneal group required less intravenous narcotics (retroperitoneal, 36.6 +/- 21 mg; transabdominal, 49.5 +/- 28.5 mg; P =.004) and less epidural analgesics (retroperitoneal, 39.5 +/- 6.4 mg; transabdominal, 56.6 +/- 9.5 mg; P =.004). Hospital length of stay (retroperitoneal, 7.2 +/- 1.6 days; transabdominal, 12.8 +/- 2.3 days; P =.024) and hospital charges (retroperitoneal, $35,587 +/- $980; transabdominal, $54,832 +/- $1105; P =.04) were significantly lower in the retroperitoneal group. The survival rates at the 40-month follow-up period were similar between the groups (retroperitoneal, 81.3%; transabdominal, 78.7%; P =.53). CONCLUSION: In this subset of patients who were at high risk for aortic reconstruction, the postoperative complications were common. However, the number of complications was significantly lower in the retroperitoneal group. Aortic reconstruction in patients of ASA class IV appears to be more safely and economically performed with the retroperitoneal approach.

Balloon angioplasty induces heat shock protein 70 in human blood vessels.

Balloon angioplasty produces a mechanically induced injury to the blood vessel wall. Heat shock protein 70 (HSP70) is a molecular chaperone whose expression can be induced by chemical or thermal stress. Thus, we hypothesized that the mechanical injury associated with balloon angioplasty would lead to increases in the expression of HSP70 in vascular smooth muscle. Segments of popliteal and trifurcation vessels from above-the-knee amputations were subject to transluminal balloon angioplasty, excised, and placed in organ cultures. Neighboring vessel that was not subjected to balloon angioplasty served as controls. Some vessels were treated with sodium arsenite (positive control, known to induce HSP70 expression). The vessels were homogenized and the proteins were separated by gel electrophoresis and transferred to Immobilon. Western blots with an antibody specific for the inducible form of HSP70 were analyzed by densitometry. Our results showed that HSP70 expression can be induced by the mechanical injury associated with balloon angioplasty in human atherosclerotic vessels.

Minimally invasive in situ bypass.

Since the report of a successful femoropopliteal in situ saphenous vein bypass in 1962, surgeons have attempted to make this bypass a less invasive operation and simplify the two principal technical components of the operation: (1) rendering the saphenous vein valves incompetent and (2) occluding the venous side branches. To accomplish this bypass, however, a long incision that is the length of the leg over the course of the saphenous vein is often necessary, which can be fraught with hazard, especially in patients with diabetes in whom wound complications can be devastating. An angioscopically assisted technique that allows the surgeon to perform valvulotomy and occlude venous side branches from within the saphenous vein--a minimally invasive in situ vein bypass--has been developed. This article discusses preclinical, fluoroscopic clinical, and angioscopic clinical studies of minimally invasive in situ bypass.

Insulin-like growth-factor-binding protein gene expression and protein production by human tumour cell lines.

The secretion of insulin-like growth-factor-binding proteins (IGFBPs) and expression of the genes encoding IGFBP-1, IGFBP-2 and IGFBP-3 have been studied in a panel of cell lines derived from breast carcinomas, Wilms' tumour, neuroblastoma, retinoblastoma, colon carcinoma, liver adenocarcinoma, Burkitt's lymphoma and a non-small-cell lung carcinoma. All cell lines, with the exception of the Burkitt's lymphoma cell line, secreted IGFBPs, as detected by affinity labelling. A 34-kDa BP was present in the conditioned media of all IGFBP-secreting cell lines, whereas BPs ranging from 18 kDa to 53 kDa were variably secreted. All IGFBP-secreting cell lines expressed the IGFBP-2 gene as determined by Northern blot analysis. The Wilms' tumour, the neuroblastoma and the retinoblastoma cell line expressed the IGFBP-2 gene only. All other cell lines, with the exception of the Burkitt's lymphoma, expressed the IGFBP-2 gene and, in addition, either the IGFBP-1 gene and/or the IGFBP-3 gene. IGFBP-1 gene expression could be detected by reverse transcriptase polymerase chain reaction only. IGFBP-3 gene expression was detected by Northern blot analysis, but transcripts were less abundant than IGFBP-2 mRNAs. These findings indicate that the expression of multiple BP genes and the secretion of BPs may be a common property of tumour cells.