Endovascular popliteal aneurysm repair: are the results comparable to open surgery?

INTRODUCTION: The aim of this study was to review our experience of popliteal aneurysms using endovascular techniques. METHODS: Thirty popliteal aneurysms in 25 patients were treated over an 11-year period. Median aneurysm diameter was 26 (16-48) mm. Five were symptomatic and 25 asymptomatic. Patients were treated with the Haemobahn/Viabahn stent-graft (26), Passager (two), Aneurx (one), and PTFE homemade device (one). Data were assessed using life table analysis, and expressed as cumulative patency rates and standard error (SE). RESULTS: Median follow-up was 24 (range 1-95) months. Primary patency was 92.9% (SE 4.5%), 84.7% (SE 6.8%), 80% (SE 8.2%), 74.5% (SE 9.4%) and 74.5% (11.3%) at 1, 6, 12, 24 and 36 months, respectively. Cumulative secondary patency was 96.5% (SE 3.3%), 88.7% (SE 6.0%), 88.7% (SE 8.6%), 83.2% (SE 8.0%) and 83.2% (SE 9.8%) at 1, 6, 12, 24 and 36 months, respectively. CONCLUSION: Endovascular treatment of popliteal aneurysms in this series achieved patency rates similar to open surgery. Aneurysm repair was performed without peroperative deaths and the risks associated with open surgery.

Superficial femoral endarterectomy with intra-arterial PTFE grafting.

PURPOSE: To report early experience with a new endovascular approach to treating occluded Wallstents in the superficial femoral artery (SFA). METHODS AND RESULTS: A symptomatic female patient with a 20-cm SFA occlusion involving a 10-cm Wallstent placed 2 years previously was offered an endovascular intervention. However, when percutaneous recanalization techniques failed, a semiclosed endarterectomy was undertaken using a conventional ring stripper. Although the atherosclerotic core and stent were removed smoothly, a small perforation was seen in the distal SFA. To avoid surgical repair, the endarterectomized segment was lined endoluminally using a 3-mm diameter, thin-walled polytetrafluoroethylene graft. A 15-mm Palmaz stent was used for distal fixation, with a plasty procedure performed at the proximal arteriotomy. There were no postoperative complications, and the patient, who was discharged on the second day, remains asymptomatic with normal flow through the graft at 3 months. CONCLUSION: Newer endovascular techniques may be applied in concert with conventional semiclosed endarterectomy to successfully treat lengthy SFA occlusions, particularly those involving stents.

Strecker stents in the femoropopliteal arteries: value of duplex ultrasonography in restenosis assessment.

PURPOSE: Experience with Strecker stent implantation in the femoropopliteal arteries has been described; however, few of the reports were prospective studies, and none routinely used site-specific assessment methods for follow-up evaluation of stent patency. The purpose of this study was to evaluate 1-year Strecker stent patency using duplex ultrasound imaging to obtain a more precise delineation of stent restenosis than is possible with other noninvasive assessment modalities. METHODS: A prospective study involved 52 patients with 57 sites treated by angioplasty and Strecker stent deployment in the femoropopliteal arteries. Assessment included clinical evaluation; ankle-brachial index (ABI) measurements at rest and after exercise; and duplex ultrasound imaging preprocedurally and at 3 and 12 months after the intervention. RESULTS: All 74 stents were deployed successfully in the 35 occluded arteries and 22 stenotic lesions. Acute reocclusion occurred in 6 (10%). At 3 months, primary patency was 81% and secondary patency 84%. Mean ( +/- SD) ABIs increased from 0.64 +/- 0.15 at rest and 0.32 +/- 0.17 after exercise to 0.89 +/- 0.14 and 0.68 +/- 0.23, respectively (p < 0.0001). At 12 months, primary patency was 79%, and secondary patency was 82%. Mean ABIs were 0.82 +/- 0.15 at rest and 0.52 +/- 0.22 after exercise at 12 months (p < 0.0002 compared with preprocedural ABIs). Analysis of the length of lesion treated showed betted results with shorter diseased segments, but this was not statistically significant (p > 0.05). Better outcomes were also obtained when one stent was used rather than two stents at 12 months (p = 0.15), but there was no difference at 3 months (p = 0.3). Thirty-four percent of the stented segments progressed from < 20% stenosis at 3 months to > 50% stenosis at 12 months. Overall, 19 (43%) of 44 segments progressed from < 50% stenosis at 3 months to a > 50% stenosis at 12 months. Restenosis seen at 3 months generally was in the native artery just proximal or distal to the stent, but at 12 months, restenosis was mainly inside the stent. CONCLUSIONS: Strecker stents at 1-year demonstrated satisfactory patency in the femoropopliteal arteries when deployed for angioplasty salvage or recurrent disease. The 3- and 12-month evaluations obtained with duplex ultrasound provided site-specific hemodynamic data for stent assessment. Resting ankle pressures were a poor index of restenosis.

Intermittent claudication in a professional rugby player.

Intermittent claudication in a professional rugby player is described. The typical features of a delayed and difficult diagnosis of an external iliac artery stenosis were found. The noninvasive diagnostic protocol used to investigate this young patient with a minimal arterial lesion enabled accurate localization and angioplasty to be performed at the same time as diagnostic angiography. The patient was symptom free with normal arterial pressures on follow-up. It is suggested that appropriate noninvasive investigations should be performed before angiography in young people with minimal lesions.

Reducing blood cholesterol levels in patients with peripheral vascular disease: dietitian or diet fact sheet?

A randomized trial was performed to test the hypothesis that, among patients with peripheral vascular disease, no difference is achieved in the magnitude of the reduction in blood cholesterol levels as a result of advice which is provided by a dietitian and that which is provided by a diet fact sheet. Fifty-nine patients were allocated at random either to a "dietitian" group (n = 31) or to a "diet fact sheet" group (n = 28). Dietary advice which was provided by a dietitian involved two personal interviews; the diet fact sheet was prepared by the NSW Department of Health. Twenty-two and 23 members of each group, respectively, returned for follow-up at three months. The mean cholesterol level fell by 8.5% among the "dietitian" group but only by 1.9% among the "diet fact sheet" group. The difference of 0.47 mmol/L in the total cholesterol level reduction between the two groups was statistically significant (P = 0.02; 95% confidence interval, -0.88 to -0.07 mmol/L). It appears that individual advice which is provided by a dietitian is more successful in leading to a reduction in blood cholesterol levels than is the administration of a diet fact sheet, even though this particular diet fact sheet appears to be excellent and is used widely. In view of the large numbers of patients and of persons in the population as a whole who would benefit from a reduction in blood cholesterol levels, and the expense of individual advice to be provided by a dietitian, explorations of cost-effective methods of providing dietary advice are needed.

Where is the immunology in cancer?

Whether the common human cancers possess tumour-specific antigens which produce an immune response in the host still remains the crucial question in tumour immunology. Recent reports and discussions at the Third International Congress of Immunology suggested that much of the previously published work was not valid. The reasons for this have been analysed by comparing the well-established experimental data with human cancer. It is suggested that much of the current confusion in tumour immunology stems from the poor models used to study human cancer and the inadequate assessment of in vitro assays which have measured the host response. The present methods require refinement, or new techniques need to be developed, before this question can be answered. The field has been well researched, and there do not appear to be any recent major advances in tumour immunology which can be applied in clinical practice.

Host resistance to a spontaneously metastasising melanoma after primary tumour excision.

Tumour resistance was investigated in a spontaneously metastasising murine melanoma. Specific tumour resistance was found in mice with intact small primary tumours and no metastases. If primary tumours were excised, resistance was demonstrated in mice which had metastases and in mice which did not have metastases but were given crude melanoma homogenate. No resistance could be detected in mice which had large primary tumours left intact or in mice which had small primary tumours excised four days prior to tumour challenge. These in vivo findings are compared with previously documented in vitro results.

Early onset of serum blocking in a murine melanoma model.

The early onset of serum blocking of host cell-mediated immunity was investigated in a transplantable murine melanoma employing two in vitro assays. One of these was based on the Takasugi and Klein cytotoxicity test; the other was a new test based on the inhibition of adherence of leukocytes to a plastic surface in the presence of tumor antigen. Both tests yielded similar results, and the adherence inhibition test was more sensitive. Blocking could be detected as early as 1 h after the inoculation of 1 times 10(7) melanoma cells. Early onset of serum blocking was also demonstrable if homogenized of tissue-cultured tumor cells were inoculated. Serum blocking under these circumstances was initially transient, declining at 24 to 48 h, but reappearing by the 4th day after inoculation. Furthermore, a functional immune system was not required for blocking factor development in this system, as evidenced by the onset of a similar pattern of blocking activity in heavily irradiated animals.

Changes in host immunity following excision of a murine melanoma.

Changes in cell mediated and humoral immunity following the excision of a transplantable melanoma growing in the footpad of its syngeneic host, as measured by an in vitro cytotoxicity test, were assessed. Spleen cell cytotoxicity did not change significantly. Cells from the regional lymph nodes stimulated tumour growth before tumour excision. Three days following tumour excision this stimulatory effect was undetectable. Loss of serum factors capable of blocking the cytotoxicity of spleen cells occurred 24 h after tumour excision. Serum cytotoxicity increased after tumour excision to a maximum of the third day. Following tumour excision the rise in serum cytotoxicity and loss of regional lymph node tumour stimulation were concomitant with the loss of blocking activity.