Vascularized Brachial Plexus Allotransplantation-An Experimental Study in Brown Norway and Lewis Rats.

BACKGROUND: Brachial plexus injuries are devastating. Current reconstructive treatments achieve limited partial functionality. Vascularized brachial plexus allotransplantation could offer the best nerve graft fulfilling the like-with-like principle. In this experimental study, we assessed the feasibility of rat brachial plexus allotransplantation and analyzed its functional outcomes. METHODS: A free vascularized brachial plexus with a chimeric compound skin paddle flap based on the subclavian vessels was transplanted from a Brown Norway rat to a Lewis rat. This study has 2 parts. Protocol I aimed to develop the vascularized brachial plexus allotransplantation (VBP-allo) model. Four groups are compared: no reconstruction, VBP-allo with and without cyclosporine A immunosuppression, VBP autotransplantation (VBP-auto). Protocol II compared the recovery of the biceps muscle and forearm flexors when using all 5, 2 (C5 + C6) or 1 (isolated C6) spinal nerve as the donor nerves. The assessment was performed on week 16 and included muscle weight, functionality (grooming tests, muscle strength), electrophysiology and histomorphology of the targeted muscles. RESULTS: Protocol I showed, the VBP-allo with cyclosporine A immunosuppression was electrophysiologically and functionally comparable to VBP-auto and significantly superior to negative controls and absent immunosuppression. In protocol II, all groups had a comparable functional recovery in the biceps muscle. Only with 5 donor nerves did the forearm show good results compared with only 1 or 2 donor nerves. CONCLUSIONS: This study demonstrated a useful vascularized complete brachial plexus allotransplantation rodent model with successful forelimb function restoration under immunosuppression. Only the allotransplantation including all 5 roots as donor nerves achieved a forearm recovery.

The possibility and potential feasibility of putting an extra functioning free muscle transplant onto a normal limb: experimental rat study.

BACKGROUND: Functioning free muscle transplantation is currently and popularly used clinically to restore motor deficit caused by traumatic muscle loss or chronic muscle denervation. However, no one uses functioning free muscle transplantation in a normal subject who has no motor deficit. This study was designed to investigate the possible and potential feasibility of transferring an extra free muscle transplant onto a normal limb. METHODS: A chimeric flap including biceps muscle with its neurovascular pedicles and a skin perforator flap was designed, harvested, and transferred from a Lewis inbred rat to the other rat overlying the original biceps following neurovascular repair where the ulnar nerve was chosen as the neurotizer. Sixteen rats were operated on and evaluated 6 months after surgery. Outcome measurements included arm circumferences, electrophysiologic studies, elbow flexion force, and muscle mass. The contralateral normal biceps was used as the control. RESULTS: All outcome measurements revealed that the extra muscle transfer resulted in significant increases in size and function of the operative limb without interfering with the original biceps function. CONCLUSION: The authors' study demonstrates the possible and potential application of using extra free muscle transplantation for functional and aesthetic augmentation purposes in a normal subject.

Comparative study of single-, double-, and triple-nerve transfer to a common target: experimental study of rat brachial plexus.

BACKGROUND: The purpose of this study was to investigate the recovery of a common target motor function after different single and combined motor nerve transfers in rat brachial plexus model. METHODS: The musculocutaneous nerve and biceps muscle were chosen as the target for neurotization. The phrenic, pectoral, and suprascapular nerves were selected as the neurotizers. Forty-two Sprague-Dawley rats were randomly assigned to seven groups (six rats in each group): single-neurotizer transfer (three groups), double-neurotizer transfer (three groups), and triple-neurotizer transfer (one group). The contralateral intact forelimb was used as a control. Functional outcomes were measured by grooming test, electrophysiological study, muscle contraction strength, muscle weight, and axon counts. RESULTS: At 12 weeks, 40 operative rats were studied (two had died). In the single-neurotizer transfer, all three transfers showed no significant difference in motor recovery of the biceps. In the double-neurotizer transfer groups, the worst results were seen in group 6 (combined pectoral and suprascapular nerve transfer) despite increasing axon counts. CONCLUSIONS: This study may potentially suggest: (1) single-neurotizer transfer will not have synergistic or antagonistic effects; (2) two neurotizers with functional antagonism will significantly downgrade motor recovery of the neurotized muscle despite increasing axon counts; (3) multiple motor neurotizer transfers may not always provide a better outcome, although increasing axons may outweigh antagonistic effects; and (4) phrenic nerve transfer alone did not upgrade the functional outcome despite its automatic discharge. Any nerve transfer combined with phrenic nerve transfer, however, showed improved functional results.

Evaluation of single-, double-, and triple-nerve transfers for shoulder abduction in 90 patients with supraclavicular brachial plexus injury.

BACKGROUND: Shoulder stability and mobility are critical to upper extremity function. The authors evaluated and compared the results of single-, double-, and triple-nerve transfer techniques in producing shoulder abduction in supraclavicular brachial plexus injuries. METHODS: Between January of 2000 and December of 2004, 90 patients with avulsion type brachial plexus injuries were selected for this study. All patients were operated on by the senior surgeon (D.C.C.C.). The brachial plexus injuries involved avulsion of five or six (including C4) roots in 41 patients (45.6 percent), four-root avulsion in five patients (5.6 percent), three-root avulsion in 25 patients (27.8 percent), two-root avulsion in 15 patients (16.7 percent), and one-root avulsion in four patients (4.4 percent). Ages ranged from 2 to 67 years, with a mean age of 29 years. All patients had nerve transfer for shoulder abduction: 43 (47.8 percent) received a single-nerve transfer, 43 (47.8 percent) received a double-nerve transfer, and four patients (4.4 percent) had a triple-nerve transfer for shoulder function. All patients had a minimum of 3 years' follow-up. Each patient's ability to abduct the shoulder was measured in degrees, and the measurements were compared statistically by nonparametric means. RESULTS: The average degree of shoulder abduction attained was 160 degrees following triple-nerve transfers, 85 degrees following double-nerve transfers, and 65 degrees following single-nerve transfer. The shoulder abduction achieved following either double-nerve transfer or triple-nerve transfer was significantly greater than that achieved by single-nerve transfer. CONCLUSION: Increasing the number of donor nerves used in early-stage nerve transfers to neurotize the avulsed brachial plexus appears to improve subsequent shoulder abduction.

Simple and reliable way in sternum wound coverage--tripedicle pectoralis major musculocutaneous flap.

OBJECTIVE: Sternotomy wound infection requires radically debridements and need secondary reconstruction of the resulting defect. Pectoralis major muscular or musculocutaneous flap is quite common in sternal wound closure. We modified the pectoralis major musculocutaneous flap design: bipedicle advancement cutaneous flap combined with thoracoacromial myocutaneous perforators, as a "tripedicle" fashion. We tried to utilize the cutaneous pedicle to provide a reliable skin coverage and decrease the wound dehiscence rate in lower one third sternal wound. METHODS: Four patients undergoing median sternotomy surgery between 2004 and 2007 suffered from sternal wound infection and received tri-pedicle pectoralis major musculocutaneous flaps transfer. RESULTS: No skin paddle necrosis or wound dehiscence occurred in the postoperative course. Cosmetically and chest stability were satisfactory without complains about the daily activity. CONCLUSIONS: Tripedicle pectoralis major musculocutaneous flap is a simple and reliable technique to cover sternal wound defect necessitating resurfacing surgery. The blood supply to the skin paddle can be enriched by the superior and inferior cutaneous pedicle and the wound dehiscence rate is decreased with this technique.

Timing of presentation of the first signs of vascular compromise dictates the salvage outcome of free flap transfers.

BACKGROUND: Microsurgical free tissue transfer has become a reliable technique. Nevertheless, 5 to 25 percent of transferred flaps require re-exploration due to circulatory compromise. This study was conducted to evaluate the timing of occurrence of flap compromise following free tissue transfer, and its correlation with salvage outcome. METHODS: Between January of 2002 and June of 2003, 1142 free flap procedures were performed and 113 flaps (9.9 percent) received re-exploration due to compromise. All patients were cared for in the microsurgical intensive care unit for 5 days. Through a retrospective review, timing of presentation of compromise was identified and correlated with salvage outcome. RESULTS: Seventy-two flaps (63.7 percent) were completely salvaged and 23 (20.4 percent) were partially salvaged. Eighteen flaps (15.9 percent) failed completely. Ninety-three flaps (82.3 percent) presented with circulatory compromise within 24 hours; 108 (95.6 percent) presented with circulatory compromise within 72 hours, and 92 flaps (85.2 percent) were salvaged within this period. One out of the three flaps presenting with compromise 1 week postoperatively was salvaged. Flaps presenting with compromise upon admission to the microsurgical intensive care unit had significantly lower complete salvage rates as compared with those without immediate abnormal signs (40.9 percent versus 69.2 percent, p = 0.01). CONCLUSIONS: The time of presentation of flap compromise is a significant predictor of flap salvage outcome. Intensive flap monitoring at a special microsurgical intensive care unit by well-trained nurses and surgeons allows for early detection of vascular compromise, which leads to better outcomes.

Frontal sinus fractures: a treatment algorithm and assessment of outcomes based on 78 clinical cases.

BACKGROUND: The purposes of this article were to retrospectively review frontal sinus fractures at the authors' center, to assess the final outcomes, and to establish a treatment algorithm. METHODS: A retrospective chart review was performed on 78 consecutive frontal sinus fractures treated by the same surgeon between January 1, 1994, and January 1, 2002. RESULTS: In this study, 57.7 percent of fractures occurred as a result of motorcycle accidents and 75.6 percent of those patients were not wearing helmets at the time of injury. The use of helmets did not significantly affect the fracture pattern. Frontal sinus fractures were commonly associated with orbital fractures (71 percent), intracranial injuries (39 percent), and severe ophthalmic injuries (26 percent). Associated injuries were more common when the fractures involved the posterior tables. The method of management comprised four groups: no surgical intervention (n = 6), open reduction and internal fixation of the anterior table with sinus preservation (n = 40), partial sinus obliteration (n = 18), and cranialization (n = 14). The complication rate was 16.7 percent (n = 13), including postoperative cerebrospinal fluid leaks (n = 6), wound infections (n = 4), meningitis (n = 1), sinusitis (n = 1), and pyomucocele (n = 1). CONCLUSIONS: Involvement of the nasofrontal duct and persistence of cerebrospinal fluid leaks are two key determinants of the treatment algorithm. The amount of displacement of the posterior table has not been found to be a key determinant of the need for surgical intervention. When the sinus is to be obliterated, partial obliteration can achieve a good result, with limited sinus complication and minimal donor-site morbidity.

Thin anterolateral thigh perforator flap using a modified perforator microdissection technique and its clinical application for foot resurfacing.

BACKGROUND: A thin skin flap is often required for optimal resurfacing of particular areas of the body. An anterolateral thigh perforator flap can be thinned to an extent to which it is vascularized by the subdermal plexus only. This study presents a novel flap thinning technique and its application for resurfacing the dorsum of the foot. METHODS: From July of 2002 to October of 2003, 18 patients underwent resurfacing of the dorsum of the foot with thin anterolateral thigh flaps. The main perforators were strategically located in the flap center to keep the peripheral area within the vascular territory. The flaps were larger than needed, initially elevated subfascially, and then thinned to the suitable thickness while the pedicle was still attached. The dissection of perforators in the adipose layer close to the dermis entry was carried out microscopically. Flap sizes ranged from 3 x 3 to 16 x 8 cm. RESULTS: Seventeen flaps survived completely and one had distal superficial necrosis of 1 x 2 cm. No debulking procedures were necessary. Average follow-up was 12 months. CONCLUSIONS: A thin flap vascularized through subdermal plexus is reliable. Microsurgical dissection of the perforator is a recommended technique. The thin anterolateral thigh perforator flap provides ideal reconstruction in resurfacing the dorsum of the foot.

Salvage of an avulsion amputated thumb at the interphalangeal joint level using afferent arteriovenous shunting.

Replantation of digits following avulsion amputation is a challenge due to the severity of damage to the digital vessels. When the digital vessels are absent or severely injured, standard artery-to-artery or vein-to-vein anastomoses may be impossible and arteriovenous shunting can be used as a salvage procedure for arterial inflow or venous drainage. Previous cases of successful replantation of avulsed digits that were reperfused using afferent arteriovenous shunting reported small segments of tissues only, usually at the level of the distal phalangeal joint or distal to it. Our case demonstrates that afferent arteriovenous shunting can also provide adequate perfusion to a large piece of tissue in the thumb even when the amputation level is at the interphalangeal joint.

Bowel preparation before microvascular free colon transfer for head and neck reconstruction: is it necessary?

Mechanical bowel preparation before any intestinal operation, especially when the large intestine is involved, is routine practice for most surgeons. This practice has been questioned by many colorectal surgeons, with convincing data showing the lack of benefit of preoperative mechanical bowel preparation. Free microvascular transfer of the large intestine is occasionally performed for reconstruction of the upper esophagus, as it provides a better size match for the oropharynx than other visceral organs. Nine patients underwent reconstruction of the cervical esophagus and voice tube using a segment of ileocolon. In all patients, the cervical esophagus was reconstructed using the ascending colon and the voice tube was reconstructed using the ileal segment. Both were transferred as one free flap. All patients underwent the procedure without any form of preoperative mechanical bowel preparation. The patients were able to tolerate a solid diet at the end of the mean follow-up period of 7 months, and all esophagograms showed no evidence of stricture formation. One patient developed a fistula at the recipient site that was treated with a regional flap, one patient developed a superficial wound infection of the abdominal wall, and one patient developed a postoperative abdominal wound dehiscence after several episodes of excessive coughing. Microvascular transfer of a large intestinal segment without preoperative mechanical bowel preparation for the reconstruction of the esophagus is a safe procedure. It can avoid the discomfort and complications associated with mechanical bowel preparation. If preoperative mechanical bowel preparation is preferred, the results of this study, which are based on nine patients, demonstrate the safety of this practice in cases where the patient did not follow proper instructions or in cases where the use of the colon was not anticipated preoperatively.

Extended trapezius myocutaneous free flap for the reconstruction of a foot defect lacking adjacent recipient vessels.

Foot reconstruction requires tissue that is durable and can withstand the extremes of pressure and stress. The trapezius myocutaneous flap has not been used previously as a free flap for foot reconstruction. In this report, the trapezius was used as an extended myocutaneous free flap for the reconstruction of a foot wound lacking adjacent and adequate recipient vessels. The extended trapezius flap may be one of the longest free flaps that can be harvested. The indications for the use of this flap are limited. In an extremity that lacks adequate recipient vessels adjacent to the defect, this flap can be extended such that more proximal vessels in the leg can be used as the recipient vessels without the need for vein grafts to bridge the distance. The donor-site morbidity of this flap is minimal when the superior fibers of the trapezius muscle and its innervation are preserved.