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Biomedical subjects

H J Buncke

Publications and source records attributed to H J Buncke.

At least 37 records · Page 2Linked to original sources
PubMed1999

Quadriceps femoris muscle flap: largest muscle flap model in the rat.

The purpose of this paper is to present a new muscle flap in the rat: the quadriceps femoris muscle flap based on a pedicle consisting of the femoral vessels. In order to establish the anatomic details of this model, seven rats were explored bilaterally, and the regional anatomy of the thigh was examined. The technical aspect of the model was established by the unilateral harvesting of 18 quadriceps femoris muscles. Findings were that this muscle is primarily supplied by a muscular branch originating at the superficial circumflex iliac artery. The average muscle weight was 6 g and the average pedicle length with femoral vessels was 6 mm. Eight of the harvested flaps were transplanted to the contralateral thigh, and the pedicle was anastomosed to the femoral vessels. The other ten flaps were resutured back to their beds. At 72 hr postoperatively, all flaps were viable with the exception of one of the transplanted flaps which was found to be necrotic. The quadriceps femoris muscle flap is technically both a reliable and simple model. With an average weight of 6 g, this flap is by far the largest described in the rat, and offers a convenient model for testing flap-related techniques and outcomes.

Animals↗
PubMed1999

Effect of hyperbaric oxygen on microvascular anastomosis healing and patency in the rat.

Recent evidence has shown that changes in blood viscosity and marked increases in both platelet count and fibrinogen concentration occur after exposure to hyperbaric oxygen (HBO). The purpose of the present study was to address whether repeated HBO therapy would increase either hematocrit or platelet count, and to determine if these changes would influence the patency of the microvascular anastomosis, as well as anastomotic healing. Eighty femoral arteries from 40 rats were divided into four groups (n = 10), and arterial anastomoses were performed on normal arteries in the first two groups, and on crushed arteries in the second two groups. One of the normal artery groups and one of the crushed artery groups received repeated HBO treatments for 5 days. Anastomotic patency rates, platelet count, hematocrit, and breaking strength were recorded. Among the results of this study were that: (1) there was no difference in patency rate following HBO treatment in both the normal and crushed artery groups; (2) platelet count was significantly higher following HBO treatment in the groups with the undamaged arteries; (3) breaking strength was significantly increased following HBO treatment in the groups with the crushed arteries. The authors concluded that HBO therapy may be useful in improving the healing of microvascular anastomoses in vessels that have undergone crush injury. Although HBO treatment results in an increased platelet count, this does not influence anastomotic patency.

Anastomosis, Surgical↗
PubMed1999

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 Bonferroni's 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.

Administration, Topical↗
PubMed1999

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.

Animals↗
PubMed1999

Serratus anterior-rib composite flap: anatomic studies and clinical application to hand reconstruction.

Because of its relative ease of dissection, increased length of the vascular pedicle, and excellent diameter for anastomosis, the serratus anterior-rib composite flap has been used to reconstruct bony and soft-tissue defects in the face and lower extremities. However, no data are available on optimal rib level or harvest location. The authors report the results of the vascular anatomy of this flap in 6 fresh cadavers and 2 clinical patients using this flap to reconstruct a defect in the hand. Arteriograms were performed through the thoracodorsal artery, and microscopic dissections were done at the rib periosteum. The sixth through the ninth ribs showed consistent filling of their respective intercostal vessels. The rib segments near the anterior axillary line had the most abundant communicating vessels between the serratus and the periosteum. In two patients, the serratus-rib composite free flap provided excellent bone and muscle length for reconstructing the first metacarpal defect.

Adult↗
PubMed1999

Patterns of flap loss related to arterial and venous insufficiency in the rat pedicled TRAM flap.

Vascular supply to the contralateral portion of the conventional transverse rectus abdominis musculocutaneous (TRAM) flap (zone IV) may become compromised, resulting in partial flap loss and requiring segmental excision. The etiology of this necrosis is not clear. This study determines skin necrosis patterns on a superiorly pedicled caudal TRAM flap during conditions of venous and arterial insufficiency, and determines whether cutaneous venous outflow can sustain a flap with venous insufficiency. Twenty-eight adult male Sprague-Dawley rats underwent superior pedicled TRAM flap elevation, and the zones were marked on the skin paddle. The animals were divided into four groups: control (group A, N = 6), arterial ligation (group B, N = 6), venous ligation (group C, N = 8), and venous ligation with cutaneous venous outflow (group D, N = 8). After 10 days, the skin paddle was photographed and the areas of necrotic skin were measured. Results showed that group B (selective arterial ligation) had 51.7 +/- 2.8% and 40.0 +/- 2.0% skin necrosis in zones I and II respectively. Zone I necrosis was significantly greater in group B compared with the control (p < 0.05). Group C (selective venous ligation) resulted in 73.8 +/- 16.4% and 93.8 +/- 33.4% skin necrosis in zones III and IV respectively. This necrosis was significantly greater compared with the control (p < 0.001). Group D rats' lateral skin necrosis compared significantly less with group C (p < 0.001). These results demonstrate that the patterns of flap necrosis in rat TRAM flaps with poor arterial inflow differ from those with venous stasis. Necrosis of the contralateral portion (zone IV) of human TRAM flaps may be related to problems with venous stasis; thus, a cutaneous venous outflow may prevent this problem.

Animals↗
PubMed1999

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.

Animals↗
PubMed1998

Results of termino-lateral neurorrhaphy to original and adjacent nerves.

In this comprehensive investigation, we studied three different neurorrhaphy models in an attempt to elucidate the potential of termino-lateral nerve repair to original and adjacent nerves. In experimental group 1, the peroneal nerve was sectioned and then attached to the posterior tibial nerve in a termino-lateral fashion. In experiment group 2, the motor nerves to the gastrocnemius muscle were sectioned and then attached to the posterior tibial nerve in a termino-lateral fashion. In experimental group 3, the obturator nerve (L2-4) was sectioned and attached to the sciatic nerve (L4-6) in a termino-lateral fashion. For the control in each group, the same type of nerve used in each respective group was transected without repair. Experimental groups 1 and 2 showed viable axons in the peroneal nerve distal to the neurorrhaphy site. Experimental group 3 showed no viable axons at these sites. No regeneration was observed in the transected nerve without repair in all three control groups. This study suggests that termino-lateral neurorrhaphy is a viable means of repairing damaged nerves if the distal segment of the sectioned nerve is reattached to its original trunk distal to its original branch point. However, the results from experimental group 3 demonstrate that termino-lateral neurorrhaphy cannot be used to repair nerves when the donor and recipient nerves originate from different spinal cord levels.

Anastomosis, Surgical↗
PubMed1998

Rat tail replantation as a training model for microvascular procedures of digit replantation.

In this study we sought to evaluate the potential of rat tail replantation as a tool for very-small-vessel microvascular anastomoses. We used 10 adult Sprague-Dawley rats. The tail was completely amputated 2.0-cm distal to the base of the tail. Then the tail was replanted with anastomoses of two superficial dorsal veins from both sides and one artery. All 10 replanted tails were pink, viable, and normal-appearing at all daily inspections performed from the first to the fourteenth postoperative days. This model can provide a training tool for the acquisition of superior microvascular surgical technique for the repair of very small vessels that stimulate digital replantation.

Amputation, Traumatic↗
PubMed1998

A new heart failure model in rat by an end-to-side femoral vessel anastomosis.

OBJECTIVE: The aim of this study was to develop a new shunting procedure for producing heart failure in the rat incorporating microvascular techniques and avoiding an abdominal operation. METHOD: We performed an end-to-side anastomosis between the femoral vein and the femoral artery just proximal to their trifurcation into the saphenous, epigastric, and distal femoral vessels. RESULTS: Of the 15 rats which underwent this procedure, six died within 48 h. The nine surviving animals were sacrificed and examined six weeks following surgery. All nine had developed cardiac hypertrophy and cardiac failure. CONCLUSION: This model provides a relatively simple and reproducible means of creating high output heart failure and cardiac hypertrophy in the rat without necessitating abdominal surgery.

Anastomosis, Surgical↗
PubMed1998

Physeal growth arrest of the distal phalanx of the thumb in an adolescent pianist: a case report.

A case of premature closure of the distal phalanx growth plate of the thumb is reported in an adolescent, presumably caused by accumulated repetitive trauma incurred during years of piano playing. The injury may be analogous to overuse injury to certain growth plates reported in child and adolescent athletes. Upper extremity problems in musicians due to the unusual and excessive demands of playing an instrument are discussed.

Adolescent↗
PubMed1998

Transfer of the rat tail: an experimental model for free osteocutaneous transfer.

A new experimental model for free transfer of the rat tail has been developed. The vascular and nerve anatomy of the tail was studied in ten Wistar rats. The caudal artery (average diameter: 0.8 mm) provides the principal arterial supply to the tail. The main venous drainage is from bilateral dorsolateral subcutaneous veins (average diameter: 1.2 mm). The inferior caudal trunk establishes the cutaneous nerve branches to the skin of the tail. Free transfer of the tail to the carotid artery and external jugular vein, with the attachment of the tail to the dorsum, allows for clinical monitoring of the transfer, without risk of autophagia. This transfer is easy to perform, simple to monitor, and provides consistent yet challenging microsurgery for the beginning microvascular surgeon. In addition to its utility as a training model, it may also have an application as an easy research model for composite tissue transfer.

Anastomosis, Surgical↗
PubMed1998

Effect of cryopreservation on survival of composite tissue grafts.

The problems in cryopreserving complex tissues remain poorly understood. In the present study, the viability of cryopreserved complex tissue, including skin and muscle flaps, and tail, was compared to simple artery and vein grafts in a rat model. Forty-four grafts, including the femoral artery (n = 15), femoral vein (n = 9), gracilis muscle flap (n = 8), groin cutaneous flap (n = 9), and tail (n = 3) were cryopreserved at -196 degrees C for 1 to 2 weeks, and then microvascularly transferred to analogous sites in inbred recipient animals. Three to 60 days post-transplant, all cryopreserved femoral arteries and veins were patent. Host groin cutaneous flaps with cryopreserved vessels grafted into the arterial pedicle survived with no complications However, severe endothelial-cell damage with extensive sloughing in the grafts was demonstrated at 30 min and 1 week following reperfusion, using factor VIII immunologic stain. Reendothelialization was evident at 2 months postoperatively. All cryopreserved composite tissue underwent early pedicle thrombosis The muscle and cutaneous tissue also showed gross and microscopic edema, with extensive red-cell extravasation within 30 min of reperfusion Cryopreservation thus can maintain the functional integrity of simple vessel grafts, but these grafts survive only as a conduit, given the severe endothelial-cell damage The failure of transferred complex cryopreserved tissue may reflect a combination of cellular or architectural damage to the capillary bed from ice formation during the freezing process and from reperfusion injury.

Animals↗
PubMed1998

Effect of hyperbaric oxygen on survival of the composite ear graft in rats.

In this study the authors set out to determine whether postoperative hyperbaric oxygen (HBO) therapy increases the survival rate of the composite graft in the rat ear model. A composite graft (1 x 0.5 cm2) that included skin, subcutaneous tissue, and cartilage was created from the left ear, and was transferred onto the posterior auricular site of the right ear. The animals were divided into two groups: a control group (N = 10) and an experimental group receiving HBO (N = 10). The experimental group was given HBO immediately following reattachment for 4 hours, and then for 6 hours each day for 5 days (2 atm). The results showed the average ear flap survival area in the experimental group was 82%, and it was 26.5% in the control group (p < 0.01). Histology demonstrated the existence of neovascularization in the experimental group. We have concluded that postoperative HBO therapy increases the survival of the rat ear composite graft, and that the effect of this therapy is influenced by the magnitude (size and thickness) of the graft.

Animals↗
PubMed1998

Microsurgical replantation of the lip: a multi-institutional experience.

Traumatic amputation of the lip is a rare yet devastating event affecting both form and function. Considering the available methods for reconstruction, replantation may offer a reasonable solution. We sought to characterize the variables associated with lip replantation and to assess the outcome in a retrospective review of 13 lip replantations performed in 12 institutions utilizing a form database and clinical and photographic analysis. Lip replantation was successful in all 13 patients; partial flap loss occurred in one patient owing to iatrogenic injury. Follow-up averaged 3.1 years. Average patient age at the time of injury was 21.1 years. There were six male and seven female patients. Injuries in two patients were the result of a human bite, the remaining injuries resulted from dog bites. One patient had significant associated injuries. Average length of hospital stay was 11.9 days. Ten patients suffered amputations of the upper lip, and three suffered amputations of the lower lip. Average defect size was 10.6 cm2. Operative time averaged 5.7 hours (range 2.5 to 12 hours). Warm ischemia time averaged 2.9 hours, and cold ischemia time averaged 2.7 hours. Donor and recipient veins were often scarce; all patients had at least one arterial anastomosis, whereas no vein was available in 7 of 13 patients; vein grafts were required in one patient. Leech therapy was employed in 11 of 13 patients. Anticoagulant therapy was administered in the majority of patients. Systemic heparin was utilized in 10 of 13 patients, low molecular weight dextran was used in 7 of 13 patients, and aspirin was given to 7 of 13 patients. One bleeding complication was incurred. An average of 6.2 units of packed red blood cells was administered to 12 of 13 patients (adjusted to 250 cc/unit). Antispasmodic therapy was employed in six of eight patients intraoperatively and in two of eight patients postoperatively. Intraoperative complications included difficulty identifying veins in 7 of 13 patients, arterial spasm in 1 of 13 patients, and vessel diameter < 0.5 mm in 4 patients. Postoperatively, one patient suffered vein thrombosis requiring anastomotic revision. Broad spectrum antibiotics were administered to all patients, and there were no infections. Nearly one-third (4 of 13) patients suffered prolonged edema lasting > 4 months. Color match of the replanted lip segment was rated excellent in all cases. Hypertrophic scarring occurred in 6 of 13 patients. A total of 12 revision procedures was performed in six patients. Interestingly, leech therapy resulted in permanent visible scarring as a result of the leech bite in 6 of 11 patients treated. Ten patients demonstrated active orbicularis muscle contraction in the replanted lip segment. Stomal continence was present in all lips. Sensibility return in the replanted lip segment was quite good with 12 of 13 patients demonstrating at least protective moving two-point sensibility (> or = 10 mm). Partial replant necrosis in one patient resulted in significant scar and contraction that compromised the aesthetic appearance. Overall, however, all patients were uniformly pleased with their final results. This clinical study is one of the largest of its kind on lip replantation. Although this represents a multi-institutional experience, the data are remarkably consistent. Re-establishment of venous outflow seems to be the most problematic technical challenge. By incorporating the adjuncts of anticoagulation, leech therapy, and antispasmodics, a successful outcome can be expected despite the paucity of vessels and small vessel size. The risks of blood transfusion, lengthy operative time, and hospital stay must be weighed against the functional benefits.

Adolescent↗
PubMed1998

The effect of an implantable Doppler probe on the salvage of microvascular tissue transplants.

One hundred forty-seven flaps in 135 consecutive patients undergoing microvascular transplantation were monitored using a miniature Doppler ultrasonic probe. Using a modification of a technique described previously by Swartz, the probes were secured to the outflow vein of the flap with Vicryl mesh. Twenty instances of thrombosis or spasm were detected in 16 patients, and all flaps were salvaged (100 percent). There were four false positive and no false negative results. This probe allows for safe, continuous monitoring of flap blood flow, which permits the rapid detection and hence rapid treatment of postoperative complications. Our experience suggests that a significant improvement in the salvage rate of microvascular transplants may be attainable with the use of this device.

Adolescent↗
PubMed1997

Arterialization of the venous system in a rat lower limb model.

Creation of alternative vascular conduits has been one of the most challenging subjects in the history of vascular surgery. In the past, afferent arteriovenous fistulas have been used by vascular surgeons to rescue ischaemic extremities. We have undertaken a comprehensive investigation to characterize arterialization of the venous system at different levels of the rat lower limb. In Group 1 (n = 28), we performed an end-to-end anastomosis between the proximal saphenous artery and the distal saphenous vein (Superficial venous system), and ligated all other branches of the femoral artery. In Group 2 (n = 28), we performed an end-to-end anastomosis between the proximal saphenous artery and the distal femoral vein (Deep venous system). In Group 3 (n = 24), the control group, the femoral artery was ligated proximal to its trifurcation into the saphenous, epigastric, and distal femoral vessels. Group 4 (n = 10), the normal group, underwent no surgery. Animals were sacrificed at the first, third, and eighth postoperative weeks. Arteriographic, India ink injection, latex injection, and histological studies were performed on all groups. Successful arterialization of veins, significant neovascularization, and less ischaemic injury of muscles were noted in the arterialized vein groups (Groups 1 and 2) when compared with the ligated group (Group 3). This model appears to depict successfully arterialization of the lower limb venous system in a small animal model.

Angiography↗