Autologous Graft Interposition Research Articles

Managing the nerve gap: New tools in the peripheral nerve repair toolbox

End-to-end repair of a peripheral nerve transection injury remains the gold standard. Delayed repair, nerve debridement and early functional mobilisation may all increase repair site tension, which impedes axon regeneration and must be avoided. Prompt diagnosis, referral to a specialist and exploration can minimise the nerve retraction, debridement and gap size, and societal benefit will be achieved through adopting a standardised approach to management. However, early exploration may provide challenges in defining the extent of the injury zone and therefore the adequacy of nerve debridement. Repair site tension can be reduced with 'sutureless' nerve approximation in a conduit, interposition of autologous graft or with interposed processed nerve allograft. Sutures can be avoided through interposition de-tensioning grafts and use of tissue glues. However, a large gap in a conduit will not support robust regeneration and grafts have two neurorrhaphy sites for axons to negotiate. Autologous graft has a donor site morbidity that may be unacceptable. An algorithm for peripheral nerve reconstruction should include the use of conduits and allograft as de-tensioning devices, avoiding the morbidity associated with autologous nerve grafting.

Vertical bone augmentation of posterior mandibular region: a description of two surgical techniques

ABSTRACT Correction of severe vertical bone deficiency in the posterior region of mandibular alveolar ridge requires surgical management if implants are scheduled and cannot have primary stability. The aim of the present study is to report two cases; one treated with alveolar osteogenesis distraction and the other with segmental osteotomy with autologous graft interposition, by describing the surgical steps as well as show the results and experiences acquired with these techniques. We opted for these methods to reconstruct the posterior mandibular region after remarkable vertical bone loss based mainly by the height and thickness of the remaining bone. Alveolar osteogenic distraction is highly advisable when vertical deficiency is severe, and if these cases are treated with the segmental osteotomy and autologous graft interposition, complications as graft failure, necrosis and resorption are more prone to occur due to insufficient vascularization. After bone maturation and bone neoformation secondary to alveolar osteogenic osteogenic distraction and segmental osteotomy with autologous graft interposition, respectively, the two presented case reports were able to securely receive dental implants. In cases of vertical bone loss of the posterior mandibular region, both surgeries currently represent the best choice for bone gain prior dental implants placement for oral rehabilitation, without technical challenges, although biological evidence to assure the superiority of one technique over the other must be further investigated.

Preoperative and Intraoperative Evaluation of Pancreatic Cancer with Vascular Involvement

Context Pancreatic carcinoma, even though distant metastases are not detectable, extends directly into the retroperitoneal spaces and involves the superior mesenteric vein (SMV) or portal vein (PV) in 25% of cases. Evidences show that patients who underwent pancreatectomy with PV and/or SMV resection and those who underwent radical resection for localized tumors, may have a comparable long term survival. Multidetector computed tomography (CT) with three-dimensional (3-D) reconstruction is an essential tool to accurately stage the disease in an attempt to identify patients who would benefit from attempted curative resection. Objective The aim of this study is to compare the results of preoperative radiological (multislice CT) evaluation with the intraoperative and histopathological findings in terms of mesenteric vessels involvement. Methods Between 2006 and 2013 we performed 130 pancreatic resections. Preoperatively, all patients underwent clinical staging with multislice CT with contrast and multiplanar reconstruction (MPR). Radiological findings were compared with surgical and histopathological results. Results Twenty cases (15.4%) radiologically showed a vascular involvement. However at laparotomy, a venous vascular resection was only performed in 10/20 cases (50%). As regard the vascular reconstruction, we performed in 3 cases a continuous suture after a tangential resection, in 7 cases a segmental resection with autologous graft interposition (with right internal jugular vein in 4 cases and with left renal vein in 1), and in 2 case a segmental resection with direct suture previous hepatic mobilization. The postoperative course had no major complications. Histological examination of resected vein wall showed: in 3 case a neoplastic infiltration limited to tunica adventitia, in 5 cases an involvement of tunica media, in 1 case an extension to intima and in 1 case there was no neoplastic infiltration. Conclusions When there are no distant metastasis, surgical radical resection provides the only chance for cure or long-term survival. In pancreatic tumors with PV/SMV involvement (borderline pancreatic cancers), oncologic radicality (negative resection margins: R0) must provide a vascular resection that actually have low morbidity and mortality. We also must consider that in more than 50% of patients the radiological vascular involvement is not confirmed at laparotomy.

Utilização da veia glicerolada na regeneração neural: Estudo experimental em ratos

A auto-enxertia de nervo é o tratamento de escolha para grandes perdas de tecido neural que não podem ser reparadas por meio de rafia primária. A utilização do enxerto venoso previamente conservado em glicerol seria uma alternativa para diminuir o tempo operatório e a morbidade cirúrgica nesses casos. Os vasos preservados em glicerol não apresentam destruição de sua estrutura, o que permite seu uso na microcirurgia vascular, tendo a vantagem de diminuir a imunogenicidade do enxerto. O objetivo deste trabalho experimental foi comparar o grau de reparação nervosa, utilizando análise histológica, contagem do número de axônios mielinizados regenerados e análise funcional, obtida com a interposição de enxerto autógeno (grupo A) e de tubo de veia glicerolada (grupo B) em defeitos de 5 mm no nervo fibular de ratos Wistar. Somente no grupo A foi observado a formação de neuroma. O grupo B apresentou padrões histológicos compatíveis com diminuição quantitativa do número de axônios mielinizados regenerados em menor número em relação ao grupo A (controle). Na recuperação funcional, não houve diferença estatisticamente significativa entre os dois grupos.