First results of clampless distal anastomosis in peripheral vascular bypass with LeGoo, a thermoreversible polymer

A New Segmental Hepatectomy Approach Using Ultrasound-Guided Portal Branch Infusion of a Thermosensitive Gel in Pigs

BACKGROUND

The aim of this study was to evaluate the safety, feasibility, and efficacy of a new segmental hepatectomy (SH) approach using intraoperative ultrasound (IOUS) guided infusion of a reversible thermosensitive gel into the portal vein branch in pigs;

MATERIALS AND METHODS

Poloxamer 407 aqueous solution (20%, W/V) was mixed with indocyanine green (P407-ICG) in this study to make it green, and it remained liquid at room temperature and turned into a firm gel upon reaching body temperature. In experiment I, six pigs were used to detect the outcome of infusing the mixture into the biliary tract, liver parenchyma, and hepatic vein for a safety study. In experiment II, another 12 pigs were randomly segmented into two groups [SH group and partial hepatectomy (PH) group] to investigate the feasibility and efficacy of the new approach using IOUS-guided infusion of the mixture into the portal branch;

RESULTS

No thermosensitive gel-induced abnormal changes were observed in the safety study. In the SH group, IOUS-guided infusion of the P407-ICG solution was effective in occluding the portal blood temporarily and demarcating the target liver segment to achieve precise SH. The blood loss in the SH group was significantly less than that of the PH group;

CONCLUSIONS

SH assisted by IOUS-guided infusion of the reversible thermosensitive gel into the feeding portal vein branches is feasible, safe, simple, and effective.

Distal bypasses in patients with diabetes and infrapopliteal disease: technical considerations to achieve success

The combination of diabetes and peripheral arterial disease (PAD) is challenging in many ways. The characteristic and complex distal distribution of PAD often encountered in patients with diabetes means that bypass surgery in this context is technically challenging. In addition, many of these patients have a burden of serious comorbidities that must be optimized and managed concurrently. While the authors acknowledge that "achieving success" in distal bypass relies on much more than technical expertise, there are some technical aspects that should be considered when planning surgery on these patients. This article outlines some important issues in the treatment pathway of a patient with diabetes and PAD requiring distal bypass surgery--from selection and optimization of the patient (in the context of a multidisciplinary team) and preoperative workup, to the operative strategy planning, technical tips, and nonoperative adjuncts. These considerations, as well as sound knowledge of the underlying disease process, confounding medical factors and awareness of the difficulty in predicting treatment outcomes, should help maximize the chances of success.

The world of LeGoo assessed: a short systematic and critical review

It is very difficult to identify whether the use of the thermosensitive polymer LeGoo offers advantages over the use of clamps or clampless techniques for infra-inguinal bypass. This issue of the journal provides much additional information about the use of LeGoo. We have summarised all the available evidence. In a very heterogeneous patient population, with heterogeneous graft type and location, the primary technical success rate remains high at 90% [95%CI 83-99], the 3 months secondary graft patency is 71 [95%CI 58-84]% and limb salvage is 78% [95%CI 68-89]%. These promising early results need to be followed by extended follow up of the patients and standardised outcome reporting in the future.

Investigations of a thermosensitive gel to temporarily occlude crural arteries in femoro-distal bypass surgery

OBJECTIVES

Long occlusions in calcified crural arteries are a major cause of endovascular technical failure in patients with critical limb ischaemia. Therefore, distal bypasses are mainly performed in patients with heavily calcified arteries and with consequently delicate clamping. A new reverse thermosensitive polymer (RTP) is an alternative option to occlude target vessels. The aim of the study is to report our technical experience with RTP and to assess its safety and efficiency to temporarily occlude small calcified arteries during anastomosis time.

METHODS

Between July 2010 and December 2011, we used RTP to occlude crural arteries in 20 consecutive patients with 20 venous distal bypasses. We recorded several operative parameters, such as volume of injected RTP, duration of occlusion and anastomotic time. Quality of occlusion was subjectively evaluated. Routine on-table angiography was performed to search for plug emboli. Primary patency, limb salvage and survival rates were reported at 6 months.

RESULTS

In all patients, crural artery occlusion was achieved with the RTP without the use of an adjunct occlusion device. Mean volume of RTP used was 0.3 ml proximally and 0.25 ml distally. Mean duration of occlusion was 14.4 ± 4.5 min, while completion of the distal anastomosis lasted 13.4 ± 4.3 min. Quality of occlusion was judged as excellent in eight cases and good in 12 cases. Residual plugs were observed in two patients and removed with an embolectomy catheter, before we amended the technique for dissolution of RTP. At 6 months, primary patency rate was 75% but limb salvage rate was 87.5%. The 30-day mortality rate was 10%.

CONCLUSIONS

This study shows that RTP is safe when properly dissolved and effective to occlude small calcified arteries for completion of distal anastomosis.

Intraoperative embolization with poloxamer 407 during surgical resection of a carotid body tumor

Surgical excision is the preferred definitive treatment for carotid body tumors, although postoperative morbidity rate as quoted in the literature is rather high. Morbidity includes cranial nerve dysfunction, stroke, and the majority severe blood loss. Embolization of the feeding branches of the external carotid artery can be performed a few days prior to surgery with the intention to decrease blood loss during operation, facilitate surgical resection, and reduce operating time and morbidity. The special risk of embolization is migration into the intracranial circulation. Poloxamer 407, a reverse-thermal polymer, is a nontoxic compound that is a viscous liquid at room temperatures but instantly changes to a firm water-soluble gel when warmed to body temperature. It dissolves spontaneously or can be dissolved at will by cooling. We describe an intraoperative technique for complete devascularization of carotid body tumor by using an intraarterial temporary occlusion technique with a poloxamer 407.