Satoshi Onoda

Use of Vascularized Free Fibular Head Grafts for Upper Limb Oncologic Reconstruction

Background: Transfer of a vascularized fibular graft is the method of first choice for reconstruction of defects of long bones. In particular, the vascularized fibula head graft is preferred for patients with bone defects of the upper limb involving the distal radius or the proximal humerus. The aim of the present study was to analyze the operative results, complications, and postoperative function after vascularized fibula head graft transfer and the indications for this procedure. Methods: From 1998 through 2008, vascularized fibula head graft transfer was performed in eight patients to reconstruct bone defects following resection of tumors of the upper limb. The primary site of the tumor was the proximal humerus in four patients and the distal radius in four patients. The postoperative course of the transferred bone was examined, and functional results were evaluated. Results: All vascularized fibula head grafts were transferred successfully. During the follow-up period, absorption of the transferred fibula head was not observed. The mean overall functional rating of the reconstructed shoulder joint was 70 percent. The range of motion of the reconstructed wrist joint showed no specific patterns, and instability of the wrist joint was observed in only one case. Conclusions: The authors believe that the vascularized fibula head graft transfer is a safe and reliable method for reconstructing the upper limb, especially for patients with a defect of the distal radius or the proximal humerus. This procedure is also useful for pediatric patients, in whom bone growth is expected after transplantation, and for salvage procedures after reconstructive materials of an artificial joint have failed.

Quantitative analysis of free flap volume changes in head and neck reconstruction.

The purpose of this study was to determine whether free flap volume decreases or increases in the long‐term postoperative period.

Prevention points for plate exposure in the mandibular reconstruction.

INTRODUCTION The rate of complications for mandibular reconstruction after segmental mandibulectomy is higher with reconstruction plates than with vascularised bone grafts. We have experience of over 100 patients using reconstructive plates for reconstruction immediately after segmental mandibulectomy and have considered factors contributing to plate exposure. PATIENTS AND METHODS Seventeen cases utilised our prevention methods in which reconstructive plates were used for mandibular reconstruction were reviewed. The flaps used with reconstruction plates were rectus abdominis myocutanenous flaps in 10 cases, anterolateral thigh flaps combined vastus lateralis muscle in four cases, and the omentum in one case; no flap was transferred in two cases. RESULTS In only one of 17 cases was a plate exposed at 3 months postoperatively. No plate exposure occurred during the follow-up period in the other 16 cases. Because no flap had been transferred in the patient with plate exposure, a possible contributing factor was the persistence of dead space beneath the plate. CONCLUSION This series suggests that factors other than flap selection contribute to the exposure of reconstructive plates. Use of a reconstruction plate is a useful reconstructive method, especially for patients who cannot tolerate transfer of a vascularised bone graft.

Minimally invasive multiple lymphaticovenular anastomosis at the ankle for the prevention of lower leg lymphedema.

The patients with secondary unilateral lower limb lymphedema are likely to experience lymphedema of the contralateral leg in the future. Our policy is to perform preventive lymphaticovenular anastomosis (LVA) of the contralateral limb without symptoms in these patients. In this report, we describe a minimally invasive preventive LVA procedure and present the preliminary results.

The best salvage operation method after total necrosis of a free jejunal graft? Transfer of a second free jejunal graft

AIM Transfer of a free jejunal graft is the first choice for reconstruction after total laryngopharyngo-oesophagectomy (TPLE). After total necrosis of a jejunal graft, possible salvage procedures include temporary external fistula formation and transfer of a second free jejunal graft. The present study determines the most appropriate salvage method. PATIENTS AND METHODS We have transferred over 600 vascularised free jejunal grafts during the past 22 years for reconstruction, immediately after TPLE, either at the National Cancer Center Hospital or at Okayama University Hospital. A second free jejunal graft was transferred to treat the first vascularised free jejunal graft that had undergone total necrosis in five of these patients. We reviewed the total number of operations, the interval between the operation and the start of oral feeding, the outcomes and the follow-up periods of the five patients. RESULTS Each of the second free jejunal grafts was positioned without complications. All patients resumed postoperative oral food intake after a mean interval of 20.4 days. Four of the five patients remain free of tumour recurrence and in good health. CONCLUSION Our results suggest that the best salvage method after total necrosis of an initial free jejunal graft is to transfer a second jejunal graft. Therefore, the severity of contamination of the neck due to jejunal graft necrosis must be minimised at re-operation to transfer a second free jejunal graft using microvascular anastomosis.

Thoracoacromial vessels as recipients for head and neck reconstruction and cause of vascular complications

Background: The choice of recipient vessels is an important factor for successful head and neck reconstruction. Finding good recipient vessels for neck microsurgery can be difficult after patients have undergone radiation therapy, previous neck dissection or developed neck infections due to pharyngocutaneous fistulae. Thoracoacromial arteries and veins can be good alternatives to common recipient vessels in such patients. We reviewed the complications, advantages and disadvantages associated with using thoracoacromial arteries and veins as recipient vessels. Methods: We reviewed eight patients whose thoracoacromial arteries and veins served as recipient vessels for head and neck reconstruction between 2002 and 2009. Preoperative status, reconstruction method and operative outcomes with complications were evaluated. Results: Postoperative complications related to microsurgical anastomosis developed in two of the eight patients. One arterial and venous thrombosis developed in each patient. We considered that the arterial thrombosis was derived from a technical problem with the operation and the venous thrombosis was derived from postoperative external pressure. Conclusions: Thoracoacromial arteries and veins are good recipient vessels for patients who have undergone ablative or reconstructive surgery, radiation therapy, or have a neck infection due to complications. However, we believe that using these vessels as recipients requires specific precautions that differ from those associated with general head and neck reconstruction.

Optimal technique for microvascular anastomosis of very small vessels: Comparative study of three techniques in a rat superficial inferior epigastric arterial flap model

OBJECTIVE The anastomosis of very small vessels (external diameter: < or = 0.5mm) is challenging and requires high microsurgical skill. This study aims to investigate the optimal technique for the anastomosis of very small vessels. We compared three anastomotic techniques on the basis of success rate and anastomosis time in a superficial inferior epigastric arterial flap model in rats. METHODS Forty-five Sprague-Dawley rats were divided into three groups of 15 rats. The superficial inferior epigastric artery flap was elevated, and only the artery was cut and anastomosed under magnification. The anastomosis was performed with the conventional technique, with the intravascular stenting technique or with the open guide suture technique. Flap survival was assessed on postoperative day 5, and the success rates of the groups were compared. In addition, the time required for anastomosis was compared between the groups. RESULTS All flaps survived, and success rates did not differ significantly between the groups. The average anastomosis times with the conventional technique (770.0s) and the intravascular stenting technique (822.8s) did not differ significantly but were significantly greater than that with the open guide suture technique (699.2s). CONCLUSION The open guide suture technique simplifies anastomosis and can be recommended as a new standard technique for the anastomosis of very small vessels. Furthermore, the benefit of the intravascular stenting technique is minimal for either skilled or unskilled microsurgeons.

Histologic Evaluation of Lymphaticovenular Anastomosis Outcomes in the Rat Experimental Model: Comparison of Cases with Patency and Obstruction.

Background: Lymphaticovenular anastomosis plays an important role in the surgical treatment of lymphedema. The outcomes of lymphaticovenular anastomosis are evaluated based on changes in edema; however, isolated assessment of the anastomosis itself is difficult. The authors used an animal experimental model to conduct a detailed examination of histologic changes associated with lymphaticovenular anastomosis and determined the factors important for success. Methods: The experimental lymphaticovenular anastomosis model was created using lumbar lymph ducts and iliolumbar veins of Wistar rats. The authors performed anastomosis under a microscope and reviewed postoperative histologic changes using optical and electron microscopy. In addition, electron microscopy and histology were used for detailed examination of the area in the vicinity of the anastomotic region in cases with patency and obstruction. Results: The patency rates immediately after, 1 week after, and 1 month after lymphaticovenular anastomosis were 100 percent (20 of 20), 70 percent (14 of 20), and 65 percent, respectively. A detailed examination of the anastomotic region with electron microscopy revealed that, in cases with patency, there was no notable transformation of the endothelial cells, which formed a smooth layer. In contrast, in obstruction cases, the corresponding region of the endothelium was irregular in structure. Conclusions: Vessel obstruction after lymphaticovenular anastomosis may be associated with irregular arrangement of the endothelial layer, leading to exposure of subendothelial tissues and platelet formation. One part of the postoperative changes after anastomosis and a cause of obstruction were elucidated in this study. The authors’ results may enable improvements in lymphaticovenular anastomosis by translating back to real clinical operations.

Non-occlusive mesenteric ischaemia of a free jejunal flap.

Free jejunal transfer using microsurgery after oesophageal or pharyngeal cancer resection is a useful operative approach. However, the disadvantage of free tissue transfer is the risk of necrosis of the transferred tissue due to impaired blood supply. In addition, jejunal flaps are more prone to blood-flow disorders such as ischaemia and congestion compared with other types of flaps. The causes of local blood supply disorders after microsurgery are divided broadly into two classes: one is thrombosis of an artery and/or vein in the anastomotic region and the other consists of local physical factors such as compressive pressure derived from haematoma formation and the effect of infection of the vascular pedicle. In this report, two rare cases of blood-flow disorder of the transferred free jejunum are described. In both cases, no signs of significant infection or occlusion of the vascular pedicles were present and late necrosis progressed gradually. The patients showed remarkable weight loss and a poor nutritional state due to inadequate preoperative nutritional intake. The necrosis was considered to be a result of non-occlusive mesenteric ischaemia of a free jejunal flap, and the factors contributing to free jejunal necrosis were reviewed.

Using MDCT to search for recipient vessels for free flaps after multiple procedures for head and neck reconstruction

Secondary reconstructive operations are needed when patients with head and neck cancers have complications, tumor recurrence after initial treatment and modification of the function or appearance. The condition of an operative field for a second or subsequent operation has often been altered because of the effects of an earlier operation or chemoradiotherapy. In particular, the rate of microsurgical complications associated with the transfer of free flaps is higher for second reconstructions because good recipient vessels in the head and neck region aremore difficult to find. The utility of multidetector-row computed tomography (MDCT) for identifying perforating vessels were reported. Because perforating vessels vary from case to case in location, number, diameter, and course, having information about perforators is extremely useful for preoperative planning. However there have been few reports of the use of MDCT for identifying recipient vessels preoperatively. Therefore, in the present study, we attempted to identify recipient vessels in the head and neck region by means of preoperative MDCT in patients who had undergone reconstruction of the head and neck region multiple times. MDCT was performed preoperatively at Okayama University Hospital to search for recipient vessels 23 times in 21 patients who had undergone reconstruction in the head and neck region one or more times. Fifteen patients received their initial treatments at another institution, and details of these treatments were not available to us. These patients had previously undergone surgery from 1 to 8 times(mean: 2.5 times). Of the 21 patients, 15 had undergone neck dissection and 16 had received radiotherapy (average dose, 45.6 Gy). All MDCT examinations were performed with an Aquilion 16 scanner (ToshibaMedical Systems Corp., Tokyo, Japan) and the parameters shown. The 3-dimensional (3D) images were rearranged with Virtual Place diagnostic imaging analysis software (AZE Ltd., Tokyo, Japan) and reconstructed by assembling numerous axial images obtained at 0.5-mm intervals.