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

L'artériopathie oblitérante des membres inférieurs (AOMI) est une pathologie de plus en plus fréquemment rencontrée en raison du vieillissement le la population et de l'augmentation de la prévalence du diabète. Les patients souffrant d'AOMI se manifestant par une ichémie critique du membre nécessitent un geste de revascularisation, afin que le risque d'amputation, acte fortement morbide, soit diminué. La revascularisation par voie endovasculaire est de nos jours la technique de premier choix mais en cas d'occlusion longue des artères jambières, une approche chirurgicale avec confection d'un pontage ne peut être évitée. La technique nécessite alors, lors de la confection de l'anastomose, de l'occlusion temporaire de l'artère en amont et en aval de rartériotomie, ce qui est réalisé traditionnellement à l'aide de clamps ou cathéters intravasculaires. Ces instruments présentent différents inconvénients reconnus - efficacité médiocre au vu d'artères fortement calcifiées et induction de lésions endothéliales notamment. Un nouveau type d'instrument est apparu sur le marché après approbation de la FDA, sous forme d'un gel thermosensible qui constitue un bouchon occlusif une fois injecté dans l'artère et se dissout spontanément après quelques minutes. Ce gel ayant été expérimenté avec succès en chirurgie cardiovasculaire chez des animaux, nous avons voulu évaluer l'efficacité et l'innocuité de son utilisation lors de la réalisation de pontages fémoro-jambier dans une cohorte de vingt patients. Différents paramètres opératoires ont été notés tels que le volume de gel injecté, les temps d'occlusion efficace et de confection d'anastomose ainsi que la qualité de l'occlusion vasculaire obtenue. Une artériographie per-opératoire a été réalisée de manière systématique à la recherche d'emboles de gel résiduel. Les taux de perméabilité primaire, de sauvetage de membre et de survie à 6 mois ont été rapportés. Les résultats sont satisfaisants puisque la qualité d'occlusion a été jugée bonne à excellente dans la totalité des cas sans qu'aucun instrument d'occlusion supplémentaire n'ait dû être employé et que le temps d'occlusion dépassait légèrement le temps nécessaire à la confection de l'anastomose. L'artériographie des deux premiers cas seulement a révélé la présence d'emboles distaux, avant que nous corrigions notre technique pour obtenir une dissolution instantanée du gel. Nous avons obtenu à 6 mois un taux de perméabilité primaire de 75% avec un taux de sauvetage de membre à 87.5%, le taux de mortalité à 30 jours étant de 10% - sans relation avec le gel. En conclusion, nous avons montré que l'utilisation de ce gel comme instrument d'occlusion vasculaire temporaire est sûre et efficace lors de la chirurgie de pontage fémoro-jambier. L'hypothèse qu'il pourrait être moins délétère pour l'endothélium et contribuer ainsi à une amélioration du taux de perméabilité des pontages distaux mériterait d'être testée dans le cadre d'une étude randomisée multicentrique

Evaluation of surgical treatment for neuropathic pain from neuroma in patients with injured peripheral nerves.

OBJECTIVE Chronic neuropathic pain after peripheral nerve injury is a major clinical problem. Its management is difficult, and therapeutic approaches vary and include oral medication, neurostimulation, and surgery. The aim of this study was to assess the adequacy of surgical nerve revision in a large series of patients with long-term follow-up. METHODS The authors reviewed the charts of 231 patients (335 nerve injuries) who experienced neuropathic pain after peripheral nerve injury and underwent surgery for nerve revision at the authors' institution between 1997 and 2012. The following parameters were recorded for each patient: history, location, duration, and severity of the pain and details of nerve revision surgery. In addition, patients were invited to participate in a follow-up consultation and were asked to score their pain at that time. Current medications and examination findings were also documented. RESULTS Elective surgery was the source of nerve injury for 55.4% of the patients. The lower extremity was the most commonly involved anatomical region (54.3%), followed by the lower abdomen (16.4%) and the thoracic region (13%). The mean time between the onset of injury and revision surgery was 48 months. On average, 1.3 injured nerves per patient were explored, and surgery was performed 1.2 times per patient. Each nerve underwent revision 1.1 times on average. Neuromas-in-continuity and scar-tethered nerves were observed in 205 nerves (61%) and terminal neuromas were observed in 130 nerves (39%). The authors performed 186 (56%) neurolyses and 149 (44%) neuroma resections and translocations. The mean follow-up of the 127 (55%) patients who agreed to come back for a consultation was 68 months. These patients indicated an average pain decrease of 4 points in the visual analog scale (VAS) score. Pain relief greater than a 2-point decrease on the VAS, a criterion for a successful treatment according to the European Federation of Neurological Societies guidelines, was encountered in 80% of patients. Pain relief did not vary in a statistically significant way with regard to surgical technique, age and sex of the patient, affected nerve, or time between trauma and surgery. Before surgery, 76% of the patients were on a regimen of paracetamol and/or NSAIDs and 44% received opiates, while after nerve revision only 37% still required simple analgesia and 14% needed opiates. CONCLUSIONS Bearing in mind that medication achieves satisfying pain relief in only 30%-40% of patients with neuropathic pain, surgery must be considered as an effective alternative therapy. No objective criteria were shown to be factors of poor prognosis. Systematic preoperative clinical mapping of the injured nerves and diagnostic nerve blocks could improve the primary success rate of the surgery

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