Hypertensive extracorporeal limb perfusion (HELP): a new technique for managing critical lower limb ischemia.

OBJECTIVE: The concept of repeatedly connecting an extracorporeal blood pump to produce pancycle suprasystolic inflow pressures to ischemic limbs is introduced. Balloon catheters allow for limb isolation from the systemic circulation. In the acute phase, it is assumed that pressure is proportion to flow (Poiseuille's Law) and in the chronic phase that collateral growth is related to endothelial shear stress and wall tension. The primary objective was to establish that increased flow could be achieved through collateral circulation in animals and in man with extracorporeal limb hyperperfusion. The second objective was to develop and test an arterial access system capable of intermittent regional hyperperfusion similar in concept to intermittent hemodialysis. Finally, to demonstrate the translocation of these concepts into humans facing major limb amputation where all standard treatment options had been exhausted. METHODS: Twelve sheep (6 hyperperfusion and 6 controls) were attached to a cardiac vortex pump and perfused at 200 mm Hg pancycle with the superficial femoral artery doubly ligated and isolated from the systemic circulation with a balloon catheter. Pressure transducers measured carotid and distal femoral pressures and the carotid-femoral index was calculated. To allow hyperperfusion to be repeated transcutaneously, a peripheral access system (PAS [Allvascular, St Leonards, New South Wales, Australia]) was constructed. This device was implanted in the common carotid artery in 8 sheep and opened approximately 3 days a week for continuous arterial access up to 37 days for 67 openings. To demonstrate these principles in humans, 3 patients with critically ischemic limbs were hyperperfused intermittently. Digital thermography compared the other limb as controls and provided objective evidence of the vascular changes. RESULTS: The mean carotid-femoral index was 0.6 +/- 0.01 for controls compared with 1.1 +/- 0.28 for the hyperperfusion group (P < .001). The collateral flow was superior to normal flow (ie, with the superficial femoral not occluded). Continuous access to the carotid arterial tree via the access device was 25.3 +/- 8.8 days with 5 of 8 devices open for the entire observational period (maximum 37 days). The human ischemic limbs were hyperperfused at 2-4 times the mean arterial pressure producing 3-6 times an increase in pump flow measurements intermittently for 53 +/- 16 hours. The clinical findings of rest pain, paresthesia, capillary return, and movement showed dramatic improvement as did thermographic emissions. Major amputation was avoided in the cases presented. CONCLUSION: Blood flow through collaterals can be very significantly augmented by connection to an extracorporeal pump with isolation from the systemic circulation. The pancycle hyperperfusion can be safely repeated by implantation of an arterial access device. In the longer term, there is evidence of collateral development. When amputation is the only alternative, hypertensive extracorporeal limb perfusion should be considered.

Long-term comparison of external valvular stenting and stripping of varicose veins.

BACKGROUND: The recurrence rate following stripping of the long saphenous vein is unacceptable. Repair of the terminal valve of the long saphenous vein is a physiological alternative. The aim of the present study was to prospectively compare the long-term recurrence rates in patients having had reparative and ablative procedures at the same time. METHODS: Patients were grouped first into those receiving high ligation and stripping of the long saphenous vein in one limb and valve repair on the contralateral side. The second group consisted of those patients who received short saphenous vein removal and valve repair of the ipsilateral long saphenous system. Finally, the effect of pregnancy on patients who received valve repairs was also studied. All patients were examined postoperatively clinically and with duplex ultrasound. RESULTS: Cumulative and absolute recurrence rates for both procedures were analysed. Over the 13-year follow-up period, external valvular stenting produced a superior outcome. The effect of pregnancy on the venous valve repair cases resulted in recurrences in 23% of cases but there was no evidence of incompetence at the site of the valve repair. CONCLUSION: If a valve repair is possible at the saphenofemoral junction, then it should be the preferred treatment option.

Intermediate to long-term results of repairing incompetent multiple deep venous valves using external valvular stenting.

INTRODUCTION: Chronic venous insufficiency is a major cause of morbidity in the community. The purpose of the present study was to assess the efficacy and safety of repairing multiple deep venous valves with an External Valvular Stent. METHODS: Forty-two limbs with chronic venous disease were operated on between 1987 and 1991. The patients included in the present series have now had more than 5 years of follow up (mean: 7.9 years; range: 5.4-11.9 years). Most patients had primary deep venous incompetence. There were 125 valve repairs out of 146 venographically suitable valves primarily in the superficial femoral and popliteal veins (2.98 per limb). Follow up was incomplete because of the duration of the trial. RESULTS: Following surgery ulcer areas decreased from a mean preoperative value of 12.9 cm2 to 1.2 cm2 at 86 months with almost 80% of the ulcers healed. All symptoms, pain, swelling, cramps and pigmentation were improved at a statistically significant level. The 90% infrared photoplethysmography recovery time almost doubled from 6.7 s preoperatively to 12.4 s at 36 months and were unchanged in the long term. Venous pressures were only significant at 12 months post implantation. Using multivariant analysis, the number of stents implanted was statistically associated with an increased number of ulcers healing. The site of venous valve repairs seems to be irrelevant to all of the variables. CONCLUSION: Multiple deep venous valve repairs are appropriate and the best form of treatment for specifically selected individuals with primary deep venous incompetence.

The treatment of varicose veins with external stenting to the saphenofemoral junction.

Presented are the experiences with 1,516 external valvular stents (Venocufft and Venocuff II) implanted at the saphenofemoral junction (SFJ) between 1985 and 2000. To assess the applicability of the procedure it was found that the appropriate implantation was performed in 34% of 310 consecutive venous procedures. To assess patient preference between external valvular stenting and simultaneous contralateral stripping, 56 consecutive patients were followed up at 3 months postoperatively. Four percent preferred stripping, 4% had no preference, and 92% preferred Venocuff IItrade mark implantation. Competence at the SFJ with specific duplex ultrasound indicators was 94% at 3 months (n = 100) and 90% at 4.8 years (n = 107). Minimal residual reflux (less than 50 mL/minute with maximum Valsalva) was present in the remainder but did not produce symptoms and very rarely progressed over the mean time of 5 years. The internal diameter (ID) of the long saphenous vein (LSV), 3 cm distal to the SFJ, changed from 7.6 +/- 2.3 mm to 4.9 +/- 1.1 mm (p < 0.001) and at the knee from 6.9 +/- 1.9 mm to 3.7 +/- 1.0 mm (p < 0.001). Patients presenting with underlying deep venous disease began with significantly higher ID, ie, 9.0 +/- 2.1 mm at the upper end of the LSV and 7.1 +/- 2.0 mm at the knee, but postoperatively the IDs reverted to those of postoperative patients with a normal deep venous system. To assess patients with recurrences, 366 limbs had simultaneous stripping and contralateral SFJ repair with the Venocuff II. Of these 33 (9%) had recurrences at 4.9 years, 82% of them on the stripping side, and on the repair side half of the recurrences had a competent SFJ (9%). Limbs with an incompetent lateral or anterior accessory system, with an incompetent SFJ (168), were compared with 11 matched randomized controls where stripping was performed. The recurrence rate was 1.2% versus 36% on the strip side. The follow-up for these cases was 6.4 years. Pregnancy (n = 14) produces a high recurrence rate, but stripping and valve repairs were not significantly different, ie, despite small numbers, there was a very strong tendency toward higher recurrence rates on the stripped side. The complication rate was small and the cost of the device is low. The method allows a repairable nonablative approach that can be offered in patients where no other surgical treatment can or should be offered. External stenting to the SFJ is the preferred option for early to moderate varicose veins involving the LSV where the clinical and ultrasonic indicators have been fulfilled.