Moxonidine inhibits Na+/H+ exchange in proximal tubule cells and cortical collecting duct

The lateral arm free flap can be harvested as a fascial flap or fasciocutaneous flap. In this report we describe the use of the lateral arm fascial flap for degloving injuries of the fingers and for skin loss on the dorsum of the hand with exposure of tendons and bones. Concomitant reconstruction of a missing phalanx with a portion of the distal humerus is also described. The use of the fascial flap allows a large area of tissue to be harvested, and still, the donor site can be closed primarily. The fascia is thin and pliable and so conforms well to the contour of the fingers. Its bulk does not interfere with finger motion, and its undersurface creates a gliding surface for tendons. Complications in the reported cases were negligible.     

A modified design of the buried radial forearm free flap for use in oral cavity and pharyngeal reconstruction

OBJECTIVE: We present a new design for the radial forearm flap that includes a small monitor segment that is connected to the primary skin paddle by a fascial subcutaneous segment of tissue. This design modification permits buried flaps to be easily monitored and provides vascularized tissue coverage of the flap vessels as well as the great vessels in the neck. Immediate augmentation of the radical neck deformity can be achieved. SETTING: This study was conducted at a referral center. PATIENTS: Fifteen patients with squamous cell cancer of the pharynx and tongue base were included in this study. The defects in these patients were judged to be best reconstructed with a radial forearm free flap. RESULTS: All free flaps in this series survived. There was one case, described in detail, in which the fascial subcutaneous portion of the flap was exposed to salivary contamination. The flap vessels remained well protected and flap viability was unimpaired.     

The application of distally based fascial pedicled island flap to rapair wound of the extremities]

In order to preserve the major vessels of the extremities in the repair and reconstruction of wounds of the extremities, the distally based fascial pedicled island flap was applied clinically. Its axis and rotatary point were designed along orientation of the major arteries, and the blood supply was from the abundant vascular networks in the deep fascia. Twenty-two cases with exposure of tendon and bone including 10 upper limbs and 12 lower limbs were treated. The flap area of forearm ranged from 7 cm x 8 cm to 12 cm x 9 cm and the ratio of the length to width of the pedicle was 1: 1-2. The flap area of the calf ranged from 10 cm x 6 cm to 16.5 cm x 12 cm and the ratio of the length to width of the pedicle was 2:1. The rotatary angle was 130 degrees-170 degrees. After operation, 18 flaps were survived completely, 2 cases had partial necrosis on the margin, 2 failures received cross-leg flap in the second operation. The patients were followed up with an average of 13.5 months (ranged from 3 months to 2 years). The conclusions were as follows: 1. the blood supply of this type of flap was reliable and the major arteries of the extremities needed not to be sacrificed; 2. the preparation of the flap was easy and the survival rate was satisfactory; 3. the shortcomings of this flap were unsightly incision scar and the limited size of flap and; 4. during the operation, the compression of the pedicle must be avoided.     

The effect of vascular endothelial cell growth factor on survival of skin flap in rats

In order to study the effect of vascular endothelial cell growth factor (VEGF) on the survival of skin flap 30 SD rats were used. A randomized flap measuring 7.5 cm x 3.0 cm was created on the back of each SD rat. The treatment group (n = 10) received VEGF 40 ng/flap by subcutaneous injection with microinjector during and 24 hours after operation. The control groups received heparin 16 U/flap (n = 10) or normal saline 800 microliters/flap (n = 10). After operation, on the 3rd and 11th day, the survival rate of the skin flaps and the dermovascular density of each flap were investigated by histological and histo-morphometrical examination. The results showed that there was no significant difference in the survival rate between the treatment group and the controls on the 3rd day after operation, while on the 11th day, there was a significant difference between them, and the survival rate was much higher in the treatment group. Besides, dermovascular density was much more increased in the treatment group than that in the controls, especially in the distal 1/3 of the flap (P < 0.02). The conclusion was that VEGF could accelerate the vascularization of the flap and enhance the survival rate of the flap.     

Arteriovenous cross-flow flap in rats: a novel skin flap

Angiosomes are blocks of tissues, composed of the integument and underlying deep structures, supplied and drained by a named artery and its accompanying vein. The purpose of the current study is to describe a new principle, which allows extension of the territory of an angiosome into the adjacent angiosome, thus enabling the creation of a large skin flap (arteriovenous cross-flow flap). Epigastric skin flaps, measuring 8 x 8 cm, were raised in 30 Sprague-Dawley male rats. In group A (single-pedicle flap), the flaps were based on the epigastric artery and vein on the ipsilateral side, and the contralateral pedicle was divided. In group B (cross-flow flap), the epigastric vein on the ipsilateral side and the epigastric artery on the contralateral side of the flap were divided. In group C (skin graft), the vascular pedicles were divided bilaterally. A definitive assessment was made on the seventh day. Digital images of the flaps were analyzed using an imaging software and the areas of skin survival and necrosis were determined. Lead oxide microangiogram was performed in another set of flaps both acutely and 1 week after flap elevation. The percent survival flap area in group A was 69.94, in group B was 89.07, and in group C was 13.00. All the groups are statistically different, with a p value < 0.001. The microangiograms showed striking differences in the vascular pattern in the cross-flow and the single-pedicle flaps. It is clearly demonstrated that the arteriovenous cross-flow flaps have increased survival of skin when compared with the conventional axial-pattern flaps.     

Posterior interosseous free flap: various types

The posterior interosseous artery is located in the intermuscular septum between the extensor carpi ulnaris and extensor digiti minimi muscles. The posterior interosseous artery is anatomically united through two main anastomoses: one proximal (at the level of the distal border of the supinator muscle) and one distal (at the most distal part of the interosseous space). In the distal part, the posterior interosseous artery joins the anterior interosseous artery to form the distal anastomosis between them. The posterior interosseous flap can be widely used as a reverse flow island flap because it is perfused by anastomoses between the anterior and the posterior interosseous arteries at the level of the wrist. The flap is not reliable whenever there is injury to the distal forearm or the wrist. To circumvent this limitation and to increase the versatility of this flap, we have refined its use as a direct flow free flap. The three types of free flaps used were (1) fasciocutaneous, (2) fasciocutaneous-fascia, and (3) fascia only. Described are 23 posterior interosseous free flaps: 13 fasciocutaneous flaps, 6 fasciocutaneous-fascial flaps, and 4 fascial flaps. There were 13 sensory flaps using the posterior antebrachial cutaneous nerve. The length and external diameter of the pedicle were measured in 35 cases. The length of the pedicle was on average 3.5 cm (range, 3.0 to 4.0 cm) and the external diameter of the artery averaged 2.2 mm (range, 2.0 to 2.5 mm). The hand was the recipient in 21 patients, and the foot in 2. All 23 flaps covered the defect successfully.     

Secondary ischemic tolerance improved by administration of L-NAME in rat flaps

Nitric oxide (NO) under basal conditions is an important regulator of vascular tone. Under ischemic conditions, however, NO can combine with superoxide anion to produce the damaging hydroxyl free radical. The current project observes the effect of inhibiting NO production (L-Nitro-amino-methyl-arginine, L-NAME) on flaps rendered ischemic by secondary (2 degrees) venous obstruction. Eighty rats had 3 x 6 cm skin flaps based on the epigastric vessels. Primary (1 degree) ischemia was produced by arteriovenous occlusion for 2 hours; (2 degrees) venous ischemia was induced by clamping the vein, alone for either 3 or 5 hours. Thirty minutes prior to 2 degrees ischemia, rats received either L-NAME (30 mg/kg) or saline buffer. Flap survival was assessed 7 days later and Chi-square analysis was used. At 3 hours of ischemia, treatment improved survival from 55% to 85% (P < 0.05). Treatment also improved survival at 5 hours of ischemia from 5% to 35% (P < 0.04). Although under resting conditions, NO is a potent vasodilator, during 2 degrees venous obstruction it may contribute to flap necrosis.     

MRI of the intracerebral lesions at 0.5 Tesla: comparison of fast spin-echo and conventional spin-echo sequences

The purpose of this study was to identify the angiosome of the medial saphenous artery and vein and to evaluate the use of this cutaneous angiosome as a free skin flap in the dog. In phase 1 of this study, selective angiography of the medial saphenous artery performed in six canine cadavers showed that the skin covering the entire medial femorotibial area, the distal half of the caudal head of the sartorius muscle, and the gracilis muscle were perfused by the medial saphenous artery. In phase 2, a medial saphenous fasciocutaneous island flap was raised and sutured back to the skin edges of the donor wound in three dogs. One hundred percent survival of all of the flaps occurred. In phase 3, a medial saphenous fasciocutaneous microvascular free flap was transferred to a wound that was created over the dorsal metacarpal (n = 3) or metatarsal region (n = 3). The mean length +/- SD of the medial saphenous vascular pedicle was 80 +/- 13 mm (n = 5); the mean diameter +/- SD of the medial saphenous artery was 2.8 +/- 0.2 mm (n = 5) and the mean diameter +/- SD of the medial saphenous vein was 4.2 +/- 0.2 mm (n = 5). One hundred percent of all flaps survived (n = 6). Selective angiography or the distal cranial tibial artery (metatarsal wounds, n = 3) and the median artery (metacarpal wound, n = 3) was performed 3 weeks after surgery. All of the vascular anastomoses were patent and neovascularization of the wound beds was present. This free flap was found to be acceptable for cosmetic reconstruction of wounds located on the distal extremity.     

''Low-risk'' myelodysplastic syndrome is associated with excessive apoptosis and an increased ratio of pro- versus anti-apoptotic bcl-2-related proteins

The aim of this study was to develop a free flap of the male prepuce. First, a dissection feasibility study was performed in eight male cadavers. Dissection proved feasible, and the mean surface area of the prepuce, when folded out, was 46.7 cm2. The mean pedicle length was 15 cm, with a mean diameter of the inferior external pudendal artery at its origin of 1.2 mm and a mean diameter of the inferior external pudendal vein at its origin of 1.9 mm. Next, a viability study was performed by isolating a prepuce free flap during male-to-female sex reassignment procedures. The flap as well as the residual skin of the penis shaft remained well perfused. Thereafter, the new prepuce free flap was successfully applied for the reconstruction of defects of the floor of the mouth, tongue, and oropharynx in two patients. The thinness and pliability of the flap, its large surface area, the long vascular pedicle, and the limited donor-site morbidity are the major advantages of this new flap. The possibility to raise the flap simultaneously with the tumor resection is an additional advantage. The small caliber of the flap artery seems to be the only drawback.     

Antibiotic resistance pattern of enterotoxigenic Escherichia coli isolated from infants and young adults in Israel

BACKGROUND: The usual methods of closure of major chest and abdominal wall defects have significant disadvantages. Skin grafts provide no structural support and result in incisional hernias. Synthetic mesh requires skin cover and is prone to infection and wound breakdown. The tensor fasciae latae (TFL) myocutaneous flap offers skin cover and a semi-rigid fascial layer. We document our unit's experience in pedicled and free TFL flaps. METHODS: The TFL flap closure of trunk defects was undertaken in 10 patients between August 1989 and April 1997. All cases were not amenable to primary closure and repair with synthetic mesh or skin grafts. RESULTS: The defect was satisfactorily repaired in all cases without subsequent herniation. The closure techniques using a pedicled TFL flap and a TFL flap for a free-tissue transfer are described. CONCLUSIONS: We conclude that the TFL flap is the method of choice for repairs of major truncal defects.     

Evolutionary anomalies among the aminoacyl-tRNA synthetases

This study demonstrates that acute mainstream cigarette smoke exposure is deleterious to dorsal random-pattern skin flap survival in the rat. Three vasodilators were also studied for their ability to mediate flap survival after smoke exposure. Sprague-Dawley rats (10 per group) were exposed to two cigarettes per day over a 14-day period. This is an exposure equivalent to that of an average cigarette smoker. Dorsal McFarlane caudally based random-pattern skin flaps (4 x 10 cm) were created on day 7 of the smoke exposure. Enteral phenoxybenzamine (0.56 mg per kilogram per day), enteral nifedipine (10 mg per kilogram per day), and topical nitroglycerin (1.3 cm or 7.5 mg per day) were administered after creation of the dorsal skin flaps in two doses daily during smoke exposure. Fluorescein was used to delineate areas of viability accurately. A pad digitizer was utilized to calculate designated skin flap areas to +/-1.0 mm2. Experimental animals demonstrated a 23% decrease (p < 0.01) in skin flap area survival compared with the control animals. The phenoxybenzamine group demonstrated a 5.5% increase in flap area survival (p=0.068), the nifedipine group demonstrated a 4.1% increase in flap area survival (p=0.049), and the nitroglycerin group demonstrated an 8.9% increase in flap area survival (p=0.049). These data suggest that phenoxybenzamine appears to affect skin flap survival marginally after smoke exposure. However, nifedipine and nitroglycerin improve random-pattern skin flap survival significantly after mainstream cigarette smoke exposure in the rat. These results imply that pharmacological intervention with vasodilators may ultimately prove clinically useful for random-pattern skin flap salvage in the cigarette-smoking patient.     

Rectus abdominis myocutaneous flaps]

The free transverse rectus abdominis myocutaneous (TRAM) flap is vascularized by the inferior epigastric pedicle. There are many techniques according to the indication. We describe the technique for breast reconstruction after mastectomy for cancer. The rectus muscle is taken between the umbilicus and the arcuate line. The skin paddle, was taken transversely like an abdominoplasty. The incision extends from 1 cm above the umbilicus to include the perforators around it. The mean length of the vascular epigastric pedicle is 6 cm. This study was performed from one hundred dissections.     

Comparison of two different delay procedures in a rat skin flap model

The overall objective of this study was to investigate how a strategic delay procedure could generate large flaps survival. On the basis of the vascular anatomy in 10 rats, a long three-territory skin flap spanning the length of the rat dorsum was designed. This flap was distally based on the deep circumflex iliac artery. The adjacent territories consisted of a large perforator of the posterior intercostal artery and the lateral thoracic artery in sequence. Two different vascular delay procedures were used and compared in nine animals. One dorsal midline incision was used to perform the two different delay procedures. The limited delay technique was performed by ligating a large cutaneous perforator of the posterior intercostal artery on one side of the rat. The extensive delay procedure was completed by ligating the cutaneous perforators of the posterior intercostal artery and the lateral thoracic artery on the other side of the rat. After a delay period of 10 days, the paired flaps were elevated, respectively, and sutured back in place. Seven days later, the area of viable skin flap was measured by the paper template technique. The animals were then killed, and the dorsal skin arteriograms were obtained by injecting a lead oxide mixture. Vascular changes of the paired flaps were assessed. In the extensive delay group, 100-percent survival was seen in four animals and distal partial necrosis was observed in five animals. The average survival area in the extensive delay group was 85.5 +/- 14.2 percent (mean +/- SD), whereas the flaps in limited delay group showed 100-percent survival in all animals (p < 0.05). In flaps that survived completely, the choke vessels among three vascular territories anastomosed throughout the flap. In the partially necrotic flaps, some choke and true anastomoses existed between the deep circumflex iliac and the posterior intercostal artery territories and the flap necrosis occurred in the third territory. This study suggests that the limited delay technique (ligation of one artery in the territory adjacent to the base of the flap) was the more effective delay procedure in the rat dorsal skin flap model.     

The use of microvascular free flaps in the repair of the skin of the upper limb

Between 1980 and 1992 microsurgical free flaps were used in 35 patients for the repair the of skin defects in the upper limb. Twenty six patients were male and nine female. The scapular flap was done in 16 cases, the lateral flap in seven, the dorsalis pedis in four, the neurovascular first web space in four, the latissimus dorsi in two, the radical forearm flap in one and the gracilis in other one. The survival rate in this series was 88.57%. Early free flaps were performed in 12 patients of whom one developed infection at the recipient site. Two-point discrimination was achieved in four thumbs reconstructed with the neurovascular first web flap. No complications occurred at the donor areas.     

Yucatan pig: an optimal hairless model for a true random cutaneous flap

Porcine models have been used extensively for skin flap research because of the established similarity between the cutaneous blood supply of the swine and humans. The Yucatan minipig provides an excellent model for researching the properties of random cutaneous flaps, offering several advantages over other breeds of swine. In this study, a total of 67 random cutaneous dorsal flank flaps measuring 4 x 14 cm were raised on nine Yucatan minipigs. The mean survival length (10.03 +/- 1.60 cm) of the nondelayed flaps was greater than others reported in the literature. The well-defined plane between the subcutaneous tissue and the panniculus carnosus facilitated flap elevation consistently above the level of the panniculus carnosus thereby ensuring the creation of a true random cutaneous flap. Furthermore, the hairless nature of the skin, particularly beneficial in studying chemical peels, permits easy visualization and monitoring of any external skin changes. These advantages make the Yucatan minipig a more desirable alternative to other breeds of swine for use in skin flap research.     

Flap prefabrication: effectiveness of different vascular carriers

A new experimental model of a vascular carrier to prefabricate a "secondary" island flap, the popliteal musculovascular pedicle, was developed in the rat. Using quantitative skin-surface fluorometry 30 minutes after sodium fluorescein injection and a flap survival area in the prefabricated 8 x 2.5-cm abdominal composite island flap, we compared the revascularization ability of our muscular carrier to nonrevascularized controls: the skeletonized arteriovenous pedicle and the fasciovascular pedicle. The free composite graft with no vascular carrier exhibited near-total necrosis. The skeletonized vascular pedicle demonstrated 15.2% +/- 7.8% perfusion of normal skin on dye fluorescence index measurements and 50% flap survival. The fasciovascular pedicle exhibited better revascularization, with a dye fluorescence index of 36.2 +/- 15.5 (p < 0.01) and 90% +/- 10% flap survival (p < 0.001). India ink injection study and histological examination of our model provided visual evidence of revascularization from the musculovascular pedicle, along with preservation of the carrier's muscular architecture. The musculovascular pedicle is a reliable carrier for making new, vascularized composite flaps.     

Fibula osteoseptocutaneous flap for reconstruction of osteoradionecrosis of the mandible

Osteoradionecrosis of the mandible poses formidable problems for treatment. In the last 6 years, the fibula osteoseptocutaneous free flap was used in 12 cases to replace mandibles with radionecrotic damage. The presence of a pathologic fracture, exposed necrotic bone, or a persistent fistula not responding to conservative treatment were the indications for such a radical approach. Mandible defects after resection were around 8.0 cm long, and in all cases intraoral mucosa, skin, or both were included with the bone excision. All vascularized fibula osteoseptocutaneous flaps transplanted were successful with good primary bone healing. Adequate facial symmetry and improvement in oral function was achieved. No evidence of osteoradionecrosis recurrence was observed after a mean follow-up period of 3 years and 9 months. The advantages of using the fibula osteoseptocutaneous flap for mandible reconstruction are numerous, and good aesthetic and functional results can be obtained when it is used for reconstruction after radical excision of osteoradionecrotic lesions.     

Clinical experience and indications of the free serratus fascia flap: a report of 21 cases

The free "serratus fascia" flap as a free flap was first described by Wintsch and named a free fascia flap of gliding tissue; however, it has not yet been given a distinct name. The particular advantages of this flap consist of an easy access and a low donor-site morbidity without functional deficit. Additionally, it may be designed very variably and molded even three-dimensionally as a tendon wraparound flap or folded to fill up cavities. In our clinic, we used this flap in 21 patients for distinct indications and in 7 patients as a vascular graft in fingers or great toe with a minimal adjacent layer of gliding tissue around the vessels for the treatment of cold intolerance after finger replantation or severe finger or toe trauma. In the other cases, this versatile flap served for the coverage of traumatically exposed tendons or bones at the extremities, covered with a skin graft. Eighteen flaps survived completely, whereas 3 flaps developed partial or superficial necrosis. Only once did a major complication by unintentional sacrification of the long thoracic nerve during flap harvesting occur, resulting in a wing scapula. We recommend this flap for defect cover at sites where a thin vascularized gliding layer for defect cover is needed, especially in distal extremities with exposed tendons or nerves, and present the current indications in discussing our experiences.     

Effect of parenteral pentoxifylline and topical nitroglycerin on skin flap survival

Flap necrosis is still a significant complication in all types of flap surgery. The effect of parenteral pentoxifylline and nitroglycerin in improving survival of ischemic skin flaps was tested in Wistar rats. In the control group (n = 15) the mean viable length of the flaps was calculated to be 6.160 +/- 0.936, and nonnecrotic flap area was found to be 1859.1 +/- 269.3. In the group treated with pentoxifylline and nitroglycerin (n = 15), the mean viable length of the flap was calculated to be 6.907 +/- 0.617, and the mean nonnecrotic flap area was found to be 2078.5 +/- 172.7. In this study results showed that the use of parenteral pentoxifylline and topical nitroglycerin is effective on skin flap survival.     

Clinical application of expanded free flaps based on primary or secondary vascularization

Prefabricated free flaps using an expansion technique were used for four reconstructive cases, including two leg reconstructions and two facial reconstructions. In this series, the prefabricated free flaps created by using the expander were classified into two types: the expanded flap based on the conventional vascular pedicle, which is called the expanded flap with primary vascularization; and the expanded flap based on the vascular pedicle in the carrier, which is called the expanded flap with secondary vascularization. The expanded flap with primary vascularization that is created in the trunk has a good indication for leg reconstruction, because it provides an wide and thin flap with minimal donor site morbidity. The expanded flap with secondary vascularization created in the pectoral region has a good indication for facial reconstruction, because it provides good color and texture matches. Although there are some disadvantages in the tissue expansion technique, the prefabricated free flaps using the expander are very effective in facial and leg reconstruction.