Teoman Dogan

Effects of VEGF administration following ischemia on survival of the gracilis muscle flap in the rat.

The incidence of free flap transplantation failure is only 3% to 5%, yet still occurs in cases in which the flap suffers prolonged ischemia. The purpose of the current study was to determine the effects of vascular endothelial growth factor (VEGF)--a potent angiogenic agent with a suspected role in the protection of endothelium--on flap survival in a model of ischemia-reperfusion injury. The model chosen was the rat gracilis muscle flap. A total of 36 adult male Sprague-Dawley rats were divided into three groups (N = 12). One experimental group received VEGF treatment and the other received heparin. A third group was treated with saline and served as the control. The gracilis muscle flap was dissected and isolated based on a vascular pedicle originating at the femoral vessels. Following 3.75 hours of ischemia, induced by clamping the femoral vessels, either VEGF, heparin, or saline was infused directly into the pedicle of the flap via a cannula. The flaps were evaluated both grossly and histologically after 72 hours of reperfusion. Eleven of the 12 flaps from the VEGF group survived, whereas the survival rate was 6 of 12 and 5 of 12 flaps for the heparin- and saline-treated groups respectively. Flap survival was significantly greater in the VEGF-treated group compared with the heparin- and saline-treated groups (p < 0.025, p < 0.01 respectively). Furthermore, there was no significant difference between the heparin and saline groups. These results indicate that VEGF plays a role in reducing the damage that occurs in ischemia-reperfusion injury, and that the use of VEGF holds promise as a potential therapy for increasing flap survival.

Closure of infratip nasal defect by two triangular flaps.

The nasal lobule is subdivided into the supratip, tip, and infratip. Various local flaps derived from the dorsal aspect of the nose are often used for resurfacing nasal tip defects, including some parts of the infratip and/or the supratip region.1–5 Isolated infratip defects after excisional therapies are less commonly encountered. In our opinion, it does not seem reasonable to reconstruct an isolated infratip defect with dorsal flaps. This article describes the use of two triangular skin flaps based on the columella for the reconstruction of such defects.

Prolonged perivascular use of verapamil or lidocaine decreases skin flap necrosis.

During this experiment the authors investigated whether prolonged local use of verapamil or lidocaine prevents vasoconstriction and establishes better blood supply to the rat epigastric skin flap, hence reducing the necrosis that occurs otherwise. Abdominal wall skin flaps of 45 Sprague-Dawley rats, based on a single pedicle of the femoral vessels, were elevated. A subcutaneous pocket for the microport valve was created, and the adjacent catheter tip was sewn next to the femoral vessels. In the control and the two treatment groups, 0.5 ml saline or vasodilator solution respectively was injected through the microport every 12 hours for 5 days. On postoperative day 5 there was no statistical difference between the flap surfaces in all groups. The area of flap necrosis was significantly lower in the verapamil- (p = 0.001) and the lidocaine-treated (p = 0.012) groups vs. the control group as determined by analysis of variance with Bonferronis post hoc test. In conclusion, topical application of verapamil and lidocaine solutions for 5 postoperative days decreased flap marginal necrosis significantly. Prolonged injection of vasodilators in the vicinity of the vascular pedicle prevents vasospasm and improves blood supply to the flap.

A new test for superficialis flexor tendon function.

Diagnosis of flexor digitorum superficialis tendon injury is difficult if the profundus tendon functions properly. A new test, called the DIP extension test, to diagnose isolated flexor digitorum superficialis tendon injuries is described. The test is particularly useful for the index finger. During the test the patient is asked to flex the proximal interphalangeal joint of the injured finger while this finger is in a precision pinch position with the thumb. The distal interphalangeal (DIP) joint normally has to go in hyperextension after this action. Inability to hyperextend the DIP joint confirms a superficialis tendon injury. Fifteen isolated superficialis tendon injuries in 10 patients were evaluated with the DIP extension test. Nine of these patients were later explored and the diagnosis was confirmed in all patients.

Saphenous neurocutaneous island flap model in the rat : Evaluation of vascular supply

Neurocutaneous flaps are utilized routinely in reconstructive surgery and even more so during the past decade. In this study, the vascular supply of the neurocutaneous flap in the rat model is presented and evaluated. Thirty-six flaps (3.5x3 cm2) were dissected on the medial aspect of the leg based on a pedicle of the saphenous nerve, saphenous artery, great saphenous vein, and the surrounding fascial tissues. Animals in the experiment were divided into five groups with different circulatory patterns of pedicle dissections. In group I (N = 12), the pedicle artery, vein, nerve, and fascia were preserved. In group II (neurocutaneous flap model, N = 24), the saphenous artery was transected and the vein, nerve, and fascia were preserved. In group III (intraneural vascular plexus circulation pattern, N = 12), the saphenous artery and the fascia were transected. In group IV (extraneural vascular plexus circulation pattern, N = 12), the saphenous artery and nerve were transected. In group V (N = 12), the entire pedicle was transected completely. Flap survival was evaluated grossly on postoperative day 7. All flaps survived in group I, but in group II 19 of 24 flaps survived completely, 3 of 24 had partial necrosis, and 2 of 24 were completely necrotic. Complete necrosis was observed in all group III flaps. In group IV, 6 of 12 flaps survived completely, 3 of 12 flaps survived partially, and 3 of 12 flaps were necrotic (p<0.05 vs. group I). Only one flap with partial necrosis survived in group V. In group II, the average survival area was not significantly different from group I (p>0.05). In conclusion, the saphenous neurocutaneous flap in the rat is a reliable microsurgical model. The saphenous neurocutaneous flap is commonly supplied by both the intraneural and extraneural vascular plexus, and although the latter is more important, neither provides sufficient vascular supply on its own.

Use of the one-finger glove for rat anesthesia.

Sir: Various techniques have been described to handle the rat for achieving intraperitoneal injection. If working with an assistant, one method is to grasp the dorsal skin of the rat’s upper back and neck with one hand and base of the tail with other and to invert its ventral surface up with the head lower than its abdomen. This allows the other person to make the injection easily.1 If working alone, one commonly used technique is to grab the tail of the rat at midportion and to lift the animal so that its hind legs are in the air, making the animal rest on the front paws. Then the injection is performed with a syringe in the dominant hand.2 However, this technique seems difficult, especially for the beginner. Although it may be safer when a relatively thick glove is worn to protect against the animal biting, the use of such gloves usually leads to a poor grasp with less control of the rat. For more control, some housing materials such as scrub shirt sleeve or a rat restraining cage can be used.1 But rat restraining cages are not readily available in every laboratory, and the cut-off sleeve of an operating room gown is relatively thin. In our laboratory, we use a thick glove, which is readily available in the market. A thick, one-finger glove is preferred because it is big enough for the rat. The glove is placed on a smooth surface with its opening wide enough for the rat to enter. While holding its tail, one guides the rat into this inviting, dark opening. Care must be taken to avoid irritating the rat. Once the rat is imprisoned in this housing material, its tail is lifted and the injection is given into the abdominal cavity (Fig. 1). The thick glove used in this way also prevents the rat from biting the handler. We believe that the described technique is a practical and safer way of holding the animal with more control for intraperitoneal injection, especially for the beginner working alone. Raffi Gürünlüoğlu, M.D. Ahmet Sönmez, M.D. Teoman Doğan, M.D. Ayhan Numanoğlu, M.D. Department of Plastic and Reconstructive Surgery Marmara University School of Medicine Istanbul, Turkey

The Peruvian fisherman's knot a new simple, and versatile self-locking sliding knot.

To the Editor: I have read the article entitled “The Peruvian Fisherman’s Knot A New, Simple, and Versatile Self-Locking Sliding Knot” by Dr. Ramirez et al with great interest. I have been using this knot technique, which I have had the good chance to learn personally from Dr. Ramirez, for 7 years. The article explains the technique in great detail and very clearly. I would still like to pinpoint an easeof-use tip for first-time users of the technique. The knot-tying technique used here is the same as the standard neck-tie knot. Just as one end of the neck-tie is pulled and the knot is drawn tight to fit the collar, this technique does the same. Used by most male plastic surgeons to tie their neck-ties everyday, this technique is very convenient to use in the operating theater, too.