Faculty Bibliography

Proximal interphalangeal (PIP) joint contractures are common complications in hand injuries and conditions such as Dupuytren's contracture. Conventional treatment such as splinting and serial casting may result in inadequate improvement. Operative release of the contracture may be complicated by neurovascular overstretch with injury to the digital nerves or vascular compromise. Gradual distraction of the contracted joint may prevent this neurovascular injury. The multiplanar distracter was designed for three-dimensional distraction of the mandible. Distraction may be obtained in the X, Y, or Z planes. With this device, the angular relationship between two planes may be altered. A 22-year-old male with a PIP joint contraction following replantation failed conventional treatment for release. With the use of a multiplanar distracter, the flexion contraction was reduced from 95 degrees to a more functional 30 degrees using gradual angular distraction. The angle between the proximal and middle phalanges were gradually changed using the ability of the distracter to change the angular relationship in the X-Y plane. At 3 and 6 months postdistraction, the patient has maintained his 30-degree flexion angle. The multiplanar distracter is a simple technique that may be useful for the treatment of PIP joint contractures that fail conventional therapy

In this study, we present our experience with balloon assisted endoscopic harvest of the latissimus dorsi muscle for extremity reconstruction. The balloon performs most of the dissection under the muscle and creates the optical work space used in the endoscopic dissection. Over the course of this series the operative time has been reduced and averaged 2 hours and 44 minutes. The reconstructive goals were met in all cases. The average axillary incision length was 5.6 cm, and there were an average of 1.3 one-centimeter or smaller counter incisions

Neuroma-in-continuity can manifest itself not only as pain but also as incomplete return of motor and sensory nerve function. The mainstay of current treatment for peripheral neuromas employs neurolysis or segmental resection with interposition grafting. These techniques are complicated by the loss of the remaining conduction through intact fibers within the injured segment. Based on the recent finding that end-to-side neurorrhaphies demonstrate axonal growth, we studied the use of a nerve 'bypass' graft as a possible alternative to neurolysis or segmental resection with interposition grafting. A sciatic nerve crush injury model was induced in the Sprague-Dawley rat by compression with a straight hemostat. Epineurial windows were created proximal and distal to the injury. An 8-mm segment of radial nerve was harvested and anastomosed to the sciatic nerve at the epineurial window sites proximal and distal to the compressed segment (bypass group). A sciatic nerve crush injury without bypass served as a control. Electrophysiological testing and gate studies were performed over an 8-week period. Sciatic nerves were then harvested en bloc and studied under transmission electron microscopy at 1250 times magnification. Myelinated and unmyelinated axon counts were obtained. Nerve conduction velocity in the bypass group was significantly faster than conduction velocity in the control group at 8 weeks (44.8 m per second vs. 36.4 m per second; p = 0.031). We found no difference in myelinated axon counts between the proximal and distal segments of the control sciatic nerve. In the experimental sciatic nerve, a 160% increase in the number of myelinated axons was noted in the distal segment. Significant axonal growth was noted in the bypass nerve segment itself. Gait analysis using the sciatic functional index revealed improved function of the bypass group compared to the control group, but this was not statistically significant. Nerve bypass may serve to augment peripheral axonal growth while avoiding further loss of the native nerve

Preoperative angiography is commonly utilized prior to free flap reconstruction of the lower extremity. The charts and radiographs of 38 patients who underwent free flap reconstruction, after acute posttraumatic lower extremity injuries, were studied. Patients were categorized according to the presence or absence of vascular abnormality based on pulse examination alone. Specific vascular abnormalities were recorded in each group. Of the 38 patients who had preoperative lower extremity arteriography, 23 were found to have normal dorsalis pedis and posterior tibial pulses. Only 1 of these patients had an angiographic abnormality. Of the 15 patients with abnormal pulse examinations, all were found to have angiographic abnormalities. Cost analysis of the lower extremity angiogram revealed a total additional expense of $2,957. Pulse examination was found to be a sensitive and effective predictor of lower extremity vascular integrity. Although lower extremity angiography is encouraged when distal pulse examination is abnormal, the use of preoperative arteriography for lower extremity microvascular free flap reconstruction is probably unnecessary in most patients with normal distal pulses

The decision to perform free flap microanastomosis to clearly uninjured vessels proximal to the zone of injury for lower extremity reconstruction must be weighed against the anatomic and technical difficulties of performing such an anastomosis. Preserved blood flow through vessels traversing the zone of injury has been shown. The records of all patients who underwent lower extremity reconstruction with microvascular free flaps at NYU Medical Center and Bellevue Hospital Center from January 1979 through August 1995 were reviewed. Patients with free flap microanastomoses distal to the zone of injury were compared with those with proximally based anastomoses. The group of patients was subdivided further into acute (1-21 days), subacute (22-60 days), and chronic (greater than 60 days) reconstruction groups. Of 451 microvascular free flaps, 35 were performed with recipient vessels distal to the zone of injury. Time interval from injury to coverage ranged from 24 hours to 57 years. Of 35 distally based flaps, 33 (94 percent) were successful and 5 required reoperation (14 percent). There was a similar incidence of thrombotic complications throughout all after-injury phases. Of 416 free flaps performed with microanastomoses to vessels proximal to the zone of injury, 388 (93 percent) were successful and 62 (15 percent) required reoperation. There was no significant difference (p > 0.05) in outcome between distal and proximal anastomoses and no significant difference (p > 0.05) in rates of reoperation. Timing of operation after injury had no bearing on outcome. Distally based microvascular free flaps anastomoses may be technically less difficult with rates of survival equal to those of proximally based flaps. The consideration and use of microanastomoses distal to the zone of injury are encouraged in selected patients

This study reviews the outcome of patients with failed free flaps to lower extremities. The failure rate was 10 percent (41 of 413 flaps) over a 13-year period. Trauma patients (83 percent of all patients) had a failure rate of 11 percent, while nontrauma patients had a failure rate of 6.7 percent. The most common cause of failure was venous thrombosis (34 percent). Eight of 36 patients (22 percent) went on to amputation after the failed free flap; all were trauma patients. Patients with tibia-fibula fractures had a 35 percent amputation rate (6 of 17 patients) after a failed free flap. Seventy-eight percent of the patients (28 of 36) had salvage of their extremities by split-thickness skin graft, local flaps, or a second free flap. Long-term follow-up was available in 24 of 36 patients (67 percent), 20 of whom were salvaged without amputation. Of the patients whose limbs were salvaged, none had undergone an amputation at a mean follow-up of 6.2 years. All were ambulating, but 7 (35 percent) had intermittent wound breakdown. Despite an initial free-flap loss, the majority of extremities can be salvaged with subsequent procedures. However, on long-term follow-up, a large percentage of patients continue to have wound problems

Microvascular thrombosis and free flap failure are complications of free tissue transfer for coverage of lower extremity soft-tissue and bony defects despite appropriate vessel selection and adherence to meticulous technique. Increased rates of flap failure have been associated with reconstruction performed between 3 days and 6 weeks after injury, as well as in patients with thrombocytosis. We have found that serum platelet levels rise significantly after lower extremity injury. It is our theory that a circulating mediator or cytokine is released in response to injury, inducing the thrombocytosis. Twenty-one patients with Gustilo grade IIIb and IIIc injuries were studied prospectively. Serum was collected throughout the postinjury period. Platelet count, leukocyte count, hemoglobin concentration, and hematocrit were determined. Samples were also subjected to a platelet aggregation study as well as enzyme-linked immunosorbent assay for interleukin-3, interleukin-6, interleukin-11, and granulocyte macrophage-colony-stimulating factor. Megakaryocyte growth and development factor enzyme-linked immunosorbent assay and a myleoproliferative leukemia virus-transfected cell line assay for thrombopoietin were performed. Bone marrow was studied with flow cytometric analysis. Mean initial platelet count was 196,000 per cubic millimeter. There was an initial 26% decline to 140,000 per cubic millimeter, followed by an increase to 361% of baseline on day 16. No significant variations in serum leukocyte count or hemoglobin concentration were seen. Spontaneous and induced platelet aggregation responses were normal. Interleukin-6 was detected at elevated levels. However, interleukin-3, interleukin-11, granulocyte macrophage-colony-stimulating factor, and thrombopoietin were not measurable. Marked megakaryocytosis was seen on bone marrow analysis. Interleukin-6 may, therefore, play a role in the mechanism of thrombocytosis. We suggest that because patients with complex bony injuries of the leg experience platelet elevations that peak approximately 2 weeks after injury, microvascular free flap reconstructions should be considered high risk during this time period

Microsurgical reconstruction of the lower extremity presents a difficult problem to plastic surgeons; the rate of failure is higher than any other anatomical site. We reviewed our recent experience with lower extremity microsurgical reconstruction using the 3M vascular coupling device. We believe the excellent patency rate of the coupler may minimize the well-described problem of venous thrombosis in this challenging group of patients. This study involves a consecutive series of 11 patients who presented for reconstructive microsurgery of the lower extremity at NYU Medical Center hospitals between June 1 and September 1, 1994. Ten of 11 patients had free flap transfer to traumatic lower extremity injuries, whereas the remaining reconstruction was in a diabetic individual with a chronic wound. Fifteen microvascular venous anastomoses were performed; all but 1 was performed using the 3M coupler. Our experience with 11 patients, involving 14 mechanically coupled venous anastomoses, demonstrated successful use of the coupler. No intraoperative or postoperative vascular complications occurred. The overall success rate of the 3M coupler for venous anastomoses was 100%, and all microvascular free flaps were successful. We recommend using the 3M coupling device for venous anastomoses during reconstructive microsurgery of the lower extremity. Our series demonstrates the safety and effectiveness of the 3M coupler in this challenging group of patients. In addition, a secondary benefit of the 3M coupler is a significant reduction in operative time

Microvascular free flaps have been successfully used to cover defects of the lower extremity. In patients with peripheral vascular disease and lower extremity defects, revascularization with in situ or reversed saphenous vein bypass graft combined with microvascular tissue transfer can salvage a limb that would otherwise be amputated. However, some of these patients may not have autologous vein available for the bypass procedure. We present a case of a 69-year-old man who underwent revascularization with a long polytetrafluoroethylene (PTFE) graft and a simultaneous microvascular free flap reconstruction using the PTFE graft as the inflow. The patient had undergone coronary artery bypass graft with saphenous vein and experienced a nonhealing wound of the distal saphenous vein harvest site and exposure of 8 cm of tibia. Angiogram revealed a significant stenosis of the common iliac artery, occluded superficial femoral artery, faint filling of the profunda femoris artery, and a faintly reconstituted posterior tibial artery. Because the patient had no available saphenous vein for bypass, he underwent an axillary-profunda and profunda-posterior tibial artery bypass with PTFE. A rectus abdominus microvascular free flap with direct anastomosis of the inferior epigastric artery to the PTFE was used to cover the exposed bone. The patient currently ambulates without difficulty. Limb salvage using bypass with PTFE combined with simultaneous microvascular free flap reconstruction is possible in selected patients

Free-flap donor sites are a frequent source of morbidity, including scar deformity and reduced mobility, as well as a significant contributor to recovery time after surgery. We present our technique for endoscopic harvest of the rectus abdominis muscle. A groin crease incision is made, which allows identification of the vascular pedicle and access to the inferior portion of the muscle. A balloon dissection device is inserted along the posterior rectus sheath and inflated. The inferior incision is closed over an endoscopic port after medial and lateral ports are inserted under direct vision at the level of the umbilicus. The cavity is insufflated with carbon dioxide, allowing visualization using a 10-mm, 30-degree endoscope. The remaining dissection is performed sharply, and the muscle is harvested via the groin incision. This technique has proved feasible during study in fresh human cadavers. Insufflation greatly reduces work load with retractors. The balloon device speeds dissection with a minimum of trauma. Because all dissection is performed from within the rectus sheath, the peritoneal cavity is not violated. Endoscopic rectus abdominis harvest using the fascial plane is safe and efficient and carries the potential to reduce donor-site morbidity