Armen K. Kasabian

In vitro prefabrication of human cartilage shapes using fibrin glue and human chondrocytes.

We report the first generation of human cartilage from fibrin glue using a technique of molding chondrocytes in fibrin glue developed in our laboratory. Human costal chondrocytes were suspended in cryoprecipitate and polymerized into a human nasal shape with bovine thrombin. After culture in vitro for 4 weeks, this construct was implanted subcutaneously into a nude mouse. The final construct harvested after 4 weeks in vivo demonstrated some preservation of its original features. Histological analysis showed features of native cartilage, including matrix synthesis and viable chondrocytes by nuclear staining. Biochemical analysis demonstrated active matrix production. Biomechanical testing was performed. To our knowledge this is the first reported creation of human cartilage from fibrin glue, and the first creation of human cartilage in vitro. This technique may become a promising means of engineering precisely designed autogenous cartilage for human reconstruction.

MICROVASCULAR FREE-FLAP SALVAGE OF THE DIABETIC FOOT : A 5-YEAR EXPERIENCE

This study reviews 21 microvascular free flaps to the diabetic foot in 19 patients over a 65-month period. All flaps were either to the plantar surface of the foot or to cover exposed Achilles tendon. Twenty of the flaps survived. The operations required a long, costly hospitalization with frequent recipient- and donor-site complications. All patients eventually ambulated on their flaps. Five patients came to proximal amputation from 6 to 37 months after surgery. Only one amputation was for flap breakdown.

The fate of lower extremities with failed free flaps.

&NA; This study reviews the outcome of patients with failed free Haps 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 Hap; 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 Haps, 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. (Plast. Reconstr. Surg. 98: 834, 1996.)

The use of subatmospheric pressure dressing for the coverage of radial forearm free flap donor-site exposed tendon complications

Since its description in China in 1978, the radial forearm free flap has become a workhorse for the reconstructive surgeon. However, the flap has known disadvantages in complications of the wrist donor site. Skin graft breakdown with exposure of the flexor tendons of the wrist is the most common. The authors describe in a patient series a new treatment for this complication. They used subatmospheric pressure dressing to stimulate granulation tissue coverage of the tendon and to facilitate epithelialization. As many as one third of all patients undergoing radial forearm free flaps develop exposed tendon complications and may benefit from Vacuum Assisted Closure (VAC) therapy.

Complications of tissue expansion in a public hospital.

Avoidance of complications in tissue expansion requires careful outpatient observation and consistent follow-up-two factors that are difficult to manage in a city hospital-based population. To determine the complication rate of tissue expanders in a given population, the authors reviewed retrospectively 34 tissue expanders placed in 30 patients at a New York City public hospital over a 7-year period from 1989 to 1996. The mean age of the patients at the time of insertion was 25 years (range, 11 months-65 years). The most common conditions for treatment were nevi (N = 11), burn scars (N = 8), breast reconstructions (N = 8), and spina bifida (N = 4). Complications occurred in 22 of 34 expanders (65%). Complications included deep infection (N = 11), exposure (N = 7), breakdown of the surgical wound (N = 4), cellulitis (N = 3), drainage (N = 1), and deflation (N = 1). Major complications resulted in premature removal in 13 of 34 expanders (38%). Minor complications leading to successful completion of the expansion process occurred with 9 of 34 expanders (27%). No complications were recorded in the remaining 12 of 34 expanders (35%). Although tissue expansion is a potentially safe and effective method of reconstruction, this review should alert the surgeon to the distinct challenges that may be encountered in the public hospital.

Acute biceps compartment syndrome associated with the use of a noninvasive blood pressure monitor.

A 29-yr-old man sustained a tibia-fibula fracture with extensive bone loss after a motorcycle accident. He had no past medical history and his vital signs were normal. He was mesomorphic, 168 cm tall, weighed 70 kg, and his physical examination was unremarkable. The patient underwent a microvascular free fibular bone transfer of the left fibula to the right tibia. Prior to surgery, a 125-mm wide NIBP cuff was wrapped firmly around the upper left arm. Cuff size was determined by visual inspection to be approximately 40% of the midarm circumference. The NIBP was cycled every 5 min (Hewlett Packard Component Monitoring System NIBP module 1008-B; Hewlett-Packard, Palo Alto, CA). A right arm vein was cannulated with a 16-gauge catheter. General anesthesia was induced with intravenous midazolam, droperidol, fentanyl, d-tubocurarine, thiopental, and pancuronium and the trachea was intubated via direct laryngoscopy. Sixty minutes after induction of anesthesia, a 20-gauge right radial arterial catheter was inserted, and the NIBP was cycled every 30 min. He was placed in the left lateral decubitus position where he remained for 9 h. The nondependent left arm was supported by a chest roll in a 60” semiflexed position. The NIBP tubing was unobstructed. Anesthesia was maintained with 0,, N,O, isoflurane, fentanyl, and pancuronium. The blood pressure (BP) varied between 110/60 and 120170 mm Hg, except for 10 min when it reached a minimum of 80/60 mm Hg. He received 8800 mL of crystalloid, 7 U of packed red blood cells, and 1000 mL of 5% albumin; blood loss was 2000 mL; urine output 1740 mL. The initial hematocrit was 40%, reached a minimum of 24%, and was 30% at the end of surgery. Arterial blood gases and electrolytes were normal. Muscle

Endoscopic Harvest of the Rectus Abdominis Free Flap: Balloon Dissection in the Fascial Plane

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.

The fate of lower extremities with failed free flaps: a single institution's experience over 25 years.

Background:Lower-extremity reconstruction with microvascular free flap coverage is often the only option for limb salvage. Flap failure rates, however, continue to have higher complication rates than those to other anatomic sites; a significant number of flaps that fail result in amputation. This study retrospectively analyzed patients treated at a single institution who underwent attempted lower-extremity limb salvage with microsurgical techniques over a 25-year period. Of particular interest are the outcome data for patients who had initial free flap failure. Patients and Methods:A prospectively maintained database was used to identify patients who satisfy criteria. Every patient who was treated with a microvascular free flap to their lower extremities was identified and included in this analysis. All records were reviewed from 1980 through 2004. Patients who had free flaps to the lower extremity fail after the initial operation were identified and selected for further analysis. Results:Five hundred eighty-eight patients who underwent microsurgical reconstruction of lower extremity wounds had a failure rate of 8.5%. Trauma patients (83%) had a failure rate of 9%. On subset analysis, the failure rate for trauma patients decreased from 11% (1980–1992) to 3.7% (1993–2004). Of patients who had a failed free flap, 18% went on to limb amputation; the remainder was salvaged with secondary free flaps, local flaps, or skin grafting. Conclusion:This single institutional experience spanning 25 years represents the longest continual series of lower-extremity free flaps reported in the literature. The improved success rate seen in the second half of the study period is attributed to a more critical selection of free-flap candidates, improved understanding of the physiology surrounding acute trauma and a more sophisticated multidisciplinary team organization.

Fate of free flap microanastomosis distal to the zone of injury in lower extremity trauma

&NA; 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.

Selective use of preoperative lower extremity arteriography in free flap reconstruction.

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