Michael Ferder

Improved survival of island flaps after prolonged ischemia by perfusion with superoxide dismutase.

Perfusion of rat groin flaps after 10 and 11 hours of complete ischemia with superoxide dismutase, an oxygen free-radical scavenger, significantly improved the survival of these flaps. This finding provides further evidence for the important role that oxygen-derived free radicals play in ischemic injury. The study also demonstrates that while restoration of blood supply alone is not enough to ensure tissue survival after prolonged ischemia, chemical agents can be utilized to achieve viable flaps beyond what was believed to be “a point of no return.”

The ten test.

&NA; The authors describe a new test for clinical sensibility, initiated in response to the need of the senior author for a rapid, reliable method to evaluate sensibility. Using this test, the patient develops a ratio between normal light moving touch and diminished moving touch. Subsequent determinations can detect serial changes. The ratios obtained can be compared with a standard scale of sensibility with a high degree of validity and reliability. The interexaminer and intraexaminer results obtained are reliable and repeatable. Statistical evaluations substantiating the validity of the test are presented. Simplicity and dependability recommend this test for use in a busy clinical setting.

1457 years of microsurgical experience

&NA; Microsurgery is a relatively new field of surgery involving various methods and practices that are currently evolving. Our goal was to register the current practices employed by the members of the American Society for Reconstructive Microsurgery. A survey was mailed to the 319 members of the society, resulting in a response rate of 33 percent (106 of 319). The data reflect the combined experience of 10,839 free‐tissue transfers and 3487 digital and upper and lower extremity replants over a 4‐year period between 1990 and 1994. Practices employed, such as pharmacologic adjuvant therapy, monitoring techniques, flap types, and success rates reported by the members of the American Society for Reconstructive Microsurgery, were analyzed. (Plast. Reconstr. Surg. 100: 355, 1997.)

The fate of tendon healing after restoration of the integrity of the tendon sheath with autogenous vein grafts

This experimental study in the chicken model compares the results of sheath closure during primary tendon surgery. Sheath closure after tendon grafting was accomplished by trapdoor of the original sheath, vein patch, and vein conduit. After casting in flexion for 14 days, the operated foot and digits were taken through a full passive range of motion every 3 days. At the 28th postoperative day, all immobilization was removed and free active range of motion and daily perching began. Active flexion was measured after death by continuous traction on the proximal profundus tendon: simulated active flexion. The unoperated contralateral foot served as the control. All operated middle toes achieved significantly greater functional return when the sheath was restored either with trap-door closure, vein conduit, or vein patch compared with simple excision of the sheath. The results indicate the efficacy of sheath closure as well as the possibility of utilizing vein patches or conduits during primary tendon repair.

Prevention of flap necrosis by chlorpromazine

Chlorpromazine administered to Sprague-Dawley rats 30 minutes prior to elevation of McFarlane back flaps and continued 14 days thereafter resulted in near complete flap survival, compared with 48 percent necrosis in control animals. Chlorpromazine demonstrates a wide variety of actions that appear to meet all presently known requirements for flap preservation.

pH-balanced solutions with superoxide dismutase (SOD): an attempt to increase island groin flap survival in rats.

Balanced salt solution (BSS) and balanced salt solution plus (BSS+), alone and in combination with heparin or superoxide dismutase (SOD), were used as irrigation solutions for rat groin flaps after prolonged ischemia. SOD always improved flap survival when it was present in solution, although when combined with BSS and BSS +, it was less effective than when combined with Ringers lactate. The physiological pH solutions BSS and BSS + had no advantages over Ringers lactate in any of the tested combinations.

A Simple Device to Control the Amount of Vasoactive Drugs Topically Applied to Blood Vessels During Experimental Studies

A simple, readily available, inexpensive device is presented that makes research of topically applied vasoactive drugs more accurate and reproducible. It is possible to recollect the drug or wash it away from the vessel. Reversal drugs can also be used in the immediate vicinity of the vessel wall.

The effect of epigastric vessel ligation on the vascular territories of the pig rectus muscle.

&NA; In a pig model, unilateral ligation of the inferior epigastric vessels caused an initial decrease in normal vascularity, followed by an increase toward normal vascularity, in the inferior portion of the rectus muscle over 42 days. Ligation appeared to dilate the choke vessels between the superior and inferior arterial territories. The results indicate that by ligation of the inferior epigastric vessels, the vascular territory, which is normally tenuous, can undergo a transposition without vascular compromise.

Skin necrosis and oral anticoagulant therapy: a review of the literature

SummaryIn spite of the wide use of oral anticoagulant therapy, skin necrosis remains an infrequent complication. A thorough search of the earlier scientific literature in English revealed sporadic cases that cannot supply enough data about the nature of this rare phenomenon. More current articles have examined this complication with recently developed and more sophisticated hematologic tests. A summary and analysis of all reported cases (a total of 105) were undertaken, in an attempt to find a common denominator that would identify the possible cause(s) of the condition, thereby allowing for improved treatment. An imbalance between clotting factors, due to lack of protein C or factor VII, seems to be the most reasonable explanation for the phenomenon, although data to validate this theory are lacking.

Prophylactic use of chlorpromazine to improve survival of random skin flaps in pigs

On the basis of earlier success in rat studies, chlorpromazine was evaluated as a probable agent for improving survival of random skin flaps in pigs. The aim was to exclude the possibility that the effect of the chlorpromazine is species specific and to find out if it is dose dependent. One hundred and five dorsally-based 12×4 cm flaps were raised unilaterally on the backs of 15 pigs. The animals were divided into three groups using 15 mg/kg chlorpromazine, 7.5 mg/kg chlorpromazine, and a saline-treated control group. Flaps in the control group averaged 40.57±3.17% necrosis, while flaps in the 15 mg/kg and 7.5 mg/kg chlorpromazine-treated groups averaged 31.53±4.77% and 11.47±2.22% necrosis respectively. These results demonstrate dose dependent beneficial affects of chlorpromazine and the survival of random skin flaps in the pig. Although ideal dose levels are still to be determined, flap survival improved with the prophylactic use of chlorpromazine at the lower 7.5 mg/kg dosage.