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Biomedical subjects

H J Buncke

Publications and source records attributed to H J Buncke.

At least 73 records · Page 4Linked to original sources

Advanced non-animal microsurgical exercises.

For the novice microsurgeon, suturing simple lines on a static model ill prepares them for the technically difficult live model that is to follow. A practice card was therefore designed to make the transition easier. The basic building block is rubber glove sutured to form a simple tube. From this point, progressive exercises are carried out. These are (1) simple suturing, (2) tube anastomosis, (3) end-to-end anastomosis, (4) end-to-side anastomosis, (5) side-to-side anastomosis, (6) inequality of diameters, and (7) free graft placement. Since the student is faced with problems that are challenging and progressively complex, a noticeable improvement is seen in their skills. These models introduce the student to planning and instrumentation that they would deal with in the clinical situation. Once the student has mastered these exercises, he/she is ready to advance to the rat model.

Animals↗

Microvascular transplantation of cryopreserved knee joints.

Successful transplantation of cryopreserved complex tissues has not yet been reported. We wanted to test whether microvascular transplantation of cryopreserved knee joints can be achieved in rats. Twenty-five knee joints were cryopreserved and then microsurgically transplanted to the groin of inbred recipient animals. Ten fresh knee joints were transplanted as controls. One week after transplantation, the transplants were evaluated in situ for pedicle patency and tissue perfusion and then harvested for histology. In all surviving rats (n = 21), the cryopreserved knee joints were well perfused immediately after transplantation. At harvest, 14 knee joints appeared viable with a patent pedicle, whereas 6 were questionably viable and demonstrated arterial thrombosis. Histologically, the viable joints revealed an intact bone and cartilage matrix; however, the number of viable chondrocytes and osteocytes was reduced. Additionally, endothelial cell plugs in some areas of the capillary bed led to scattered microinfarctions despite a patent vascular pedicle. The nonperfused transplants showed infarction. In conclusion, we have demonstrated successful microvascular transplantation of cryopreserved knee joints with reduced short-term viability. Long-term studies must determine whether full recovery occurs.

Animals↗

Calcific myonecrosis following compartment syndrome: report of two cases, review of the literature, and recommendations for treatment.

Calcific myonecrosis of lower extremity muscles has been identified as an uncommon late sequela of posttraumatic compartment syndromes or ischemic myonecrosis. Previous reports have detailed a small number of cases with similar clinical and radiographic features. Two cases of calcific myonecrosis diagnosed more than 30 years following trauma to an extremity are presented. Treatment consisted of serial debridement of all infected and necrotic tissue followed by wound closure using a rectus abdominis muscle microvascular transplant in one patient and delayed primary closure in the other. Both patients have resumed active lifestyles with no recurrence of drainage or infection. Aggressive debridement and definitive soft tissue coverage are the mainstay of effective treatment for this entity.

Anti-Bacterial Agents↗

Fetal reconstructive surgery: experimental use of the latissimus dorsi flap to correct myelomeningocele in utero.

A recent study in human fetuses with myelomeningocele produced evidence that nonclosure of the spine leads to progressive damage of the exposed spinal cord during pregnancy. Thus in utero coverage might spare function. We tested the use of the latissimus dorsi flap for fetal myelomeningocele repair. In seven sheep fetuses, a lumbar myelomeningocele type of lesion was created at 75 days' gestation and was covered with a "reversed" latissimus dorsi flap at 100 days. At term, the three survivors had healed cutaneous wounds and normal hindlimb function. The vascular pedicle of the latissimus dorsi flap was patent, the viable flap covered the entire lesion, and the underlying spinal cord was grossly intact. We conclude that the latissimus dorsi flap repair is suitable for fetal surgery and provides efficient coverage of the lesion. These results have clinical implications, since fetal myelomeningocele repair may be a compelling way to reduce the severe neurologic deficit in humans.

Animals↗

[202 toe transfers to the hand].

This retrospective study analyzed 202 toe-to-hand transplants performed over the last 20 years at the Davies Medical Center, San Francisco (USA). The overall success rate was 97%. Toe transplants for finger reconstruction yielded optimal functional and cosmetic results due to their anatomical similarity to fingers. The great toe was preferably used for thumb reconstruction, whereas the other toes were used for reconstruction of the long fingers. Early reconstructions, multiple simultaneous toe transplants, and interventions combining toe transplantation with free flaps seemed to be advantageous because of shorter rehabilitation and comparable results.

Activities of Daily Living↗

The greater omentum transplantation model in the rat.

Dissection of the rat omentum were performed to study the feasibility of rat omental free transfer. The right epiploic vessels were found to be adequate for anastomosis in transfer. Twelve omental free flaps were transferred to the groin, with 100% survival of flaps in the 10 animals that survived the operation. The artery and vein averaged 0.3 and 0.4 mm in diameter, respectively. The average pedicle length was 5 mm, and the average flap weight was 136.9 mg. This omental transplant offers a new experimental means of studying lymphedema, neovascularization, and tissue revascularization.

Animals↗

Primary common bile duct anastomosis in the rat using microsurgical techniques.

In a rat model, we attempted to describe the natural healing course of the common bile duct (CBD) after primary microsurgical repair. Fifty-three rats were divided into experimental groups with CBD microsurgical anastomoses and control groups with CBD mobilization and ligation. Examination of three experimental groups at 1 week, 1 month, and 3 months showed evolving inflammation and stricture changes with eventual patent, healed ducts in 92% of animals at the end of 3 months following transection and repair. There were no histologic abnormalities in the livers. There were fibrotic ducts and hepatic stasis and cirrhosis changes in the control group with CBD ligation. This study demonstrates that microsurgical techniques can achieve successful primary biliary repair in the rat.

Anastomosis, Surgical↗

Sensory reinnervation of muscle free flaps for foot reconstruction.

A retrospective study was performed to measure sensibility in sensory-to-motor innervated microvascular muscle transplants to the foot. Seven transplants were on the weight-bearing surface of the foot. Five of seven flaps had light-touch sensation. Mean vibrometer readings of the innervated transplants were 15.7 (range: 5 to 40) vs. 5.3 (range 2 to 9) on the contralateral foot. Semmes-Weinstein scores of the innervated flaps were 3.84 (one), 4.74 (one), 5.46 (two), and 6.45 (three) vs. 3.22 (one), 3.84 (one), 4.08 (one), and 4.17 (four) on the contralateral foot. This study documents that sensory-to-motor innervated free muscle flaps may regain measurable sensibility.

Adult↗

Microsurgical vascularized free temporoparietal fascia transfer for Peyronie's disease: an experimental study.

This experimental study on 24 male rats evaluated the advantages of vascularized vs. nonvascularized temporoparietal free fascia transfer as an improved form of penile tunica albuginea replacement. The paper describes in detail steps in these techniques and offers functional, anatomic, and histologic follow-up after 3 months. All 24 rats developed straight corpora cavernosa in erection. The flap was successful in each case, providing satisfactory morphologic appearance with minimal bulk. The only differences were histologically provided. Secondary degenerative changes were identified in all penises with nonvascularized fascial transfer, and one-third of penises with vascularized temporoparietal fascia free transfer. These results encourage vascularized free-tissue transfer application as an optimal solution in human penile reconstructive surgery.

Animals↗

Intestinal flora of the medicinal leech Hirudinaria manillensis.

Medicinal leeches are widely used to treat venous congestion in microvascular surgery. Aeromonas hydrophila infection, following application of the leech species Hirudo medicinalis, is a recognized complication. Administration of antibiotics directed at Aeromonas has been successful in minimizing complications of infection from this organism. A different leech species, Hirudinaria manillensis, has recently been introduced for microsurgical use. A study of the enteric content of 30 of these leeches showed that Aeromonas hydrophila was isolated in only 20 percent of animals, while the majority of remaining positive cultures were single and mixed gram-negative rods. All organisms isolated were sensitive to current recommended coverage for Aeromonas hydrophila. This study suggests that the enteric flora of different leech species may be variable and should be carefully characterized, to direct appropriate prophylactic therapy prior to release of new species for clinical use.

Aeromonas↗

Microvascular vein-graft patency in the rat model.

This study establishes a controlled model, to examine the patency rates of simple, arterial and venous anastomoses, compared to vessel repairs performed with 10-mm, size-matched, interpositional, vein grafts in the rat femoral artery and vein. Patency rates in two control groups, consisting of 68 Sprague-Dawley rats in which simple, femoral-vessel repairs were performed, were compared to three experimental groups, consisting of 94 animals in which the femoral vessels were repaired with interpositional vein grafts. No statistically significant difference was found in the patency rates of arterial (p = 0.487) or venous repairs (p = 0.472) in the control groups. Nor was a significant difference found in arterial vein-graft patency (p = 0.560) or venous vein-graft patency (p = 0.862), when compared to the control groups. This study illustrates that, in the controlled laboratory setting, 10-mm, size-matched, interpositional, vein grafts have statistically the same patency rates as simple repairs of the rat femoral artery and vein.

Anastomosis, Surgical↗

Microvascular vein grafts in the rat cutaneous free-flap model.

This study utilizes the rat free groin-flap model to evaluate the survival of free flaps following revascularization with interpositional vein grafts. One hundred and fifty-three Sprague-Dawley rats were divided into a control group in which the groin flap was revascularized by simple end-to-end anastomosis, and three experimental groups revascularized with 10-mm, size-matched, interpositional, vein grafts to the femoral artery (Experimental Group 1), to the femoral vein (Experimental Group 2), and to both arterial and venous femoral vessels (Experimental Group 3). No statistically significant difference was noted in survival rates, when the experimental groups were compared to the control group (p1 = 0.619, p2 = 0.677, p3 = 0.666). As demonstrated by this study, free-tissue transfers in the rat, utilizing 10-mm, interpositional, vein grafts that are size-matched, and performed in a controlled laboratory setting, have the same survival rates as those revascularized by primary arterial and venous repairs.

Anastomosis, Surgical↗

New perioral arterial flaps: anatomic study and clinical application.

We studied the vascular anatomy of the perioral region by dissecting fresh cadavers. The anatomy of perioral branches of the facial artery consistently confirmed the existence of a septal branch and an alar branch to the upper lip and a vertical labiomental branch to the lower lip. New regional flaps supplied by these perioral arterial branches are proposed in this paper. The mucosal flap from the upper lip supplied by the deep septal branch or the alar branch of facial artery can be used to restore lower lip defects. A composite flap from the lower lip supplied by the vertical labiomental branch of the facial artery can be used safely to restore combined defects of the upper lip and nose or partial defects of the lower lip.

Adult↗

Simultaneous free-tissue transfer and Ilizarov distraction osteosynthesis in lower extremity salvage: case report and review of the literature.

The last decade has witnessed the refinement of microvascular tissue transplantation and its application in treating difficult open wounds. Nonetheless, severe type III tibial injuries continue to challenge reconstructive surgeons. The clinical presentation and surgical treatment of a type IIIB tibial fracture, complicated by long-standing chronic osteomyelitis, angulation deformity, and bone shortening, is presented. This case illustrates the benefit of combining microvascular transplantation of distant tissues with the Ilizarov technique of distraction osteosynthesis in the treatment of complicated lower extremity injuries.

Abdominal Muscles↗

Microvascular transplant of the gastrocnemius muscle in rats.

The rat gastrocnemius muscle can serve as a vascularized, innervated muscle transplant model. To establish the anatomic and technical details of this model, we performed ten gastrocnemius transplants and collected data on muscle weight, dimension, and vessel caliber from each muscle. The muscle, consisting of medial and lateral heads, is supplied by pairs of sural vessels averaging 0.2 mm in diameter. These vessels, however, can be taken in continuity with the femoral vessels (averaging 1.0-1.6 mm in diameter), which are used for transplantation. The muscles weighed an average of 2.8 g, and the average pedicle length was 24 mm. Eight of ten transplanted muscles were viable with intact circulation at 72 hr. The gastrocnemius transplant was technically reliable, and the muscle bulk and contour could allow biochemical and functional studies. Donor site morbidity limits this model to transplantation studies.

Animals↗

Microvascular transfer of the rectus abdominis muscle and myocutaneous flap in rats.

A rat microvascular free rectus myocutaneous flap model with a superior epigastric vessel pedicle is presented. The rectus muscle has a predictable "flow-through" axial vascular system consisting of superior and inferior epigastric vessels anastomosing under the fascial sheath, and six to seven musculocutaneous perforating branches to the skin. The superior epigastric artery and vein, averaging 0.45 mm and 0.5 mm in diameter, can be used as the vascular pedicle in muscle or myocutaneous flap transplantation. Eight muscle and 15 myocutaneous flaps were transplanted to the groin. The myocutaneous flaps averaged 3.5 cm by 1.2 cm in size; the pedicle length averaged 11 mm. The 5 day survival was 100% for muscle flaps and 67% for myocutaneous flaps. The rectus myocutaneous flap is believed to be the first true myocutaneous model in the rat.

Abdominal Muscles↗

Salvage of wounds following failed tissue transplantation.

During the past 20 years, 972 microvascular transplantations have been performed for 783 patients, with an overall failure rate of 6.2 percent. Fifty-four of the 60 failed transplantations were available for long-term follow-up and were retrospectively reviewed with respect to the original indications for transplantation, the number, and the type of salvage procedures performed following transplant failure. This study illustrates that the choice of salvage procedures performed following transplant failure depends on the original indications, the location, and the severity of the resultant wound. Failure following transplantation for coverage of contour defects or unstable wounds can often be managed by non-microsurgical methods. In contrast, when the indications for transplantation included the transfer of specialized tissues for thumb or digit reconstruction, the restoration of motor or sensory function, or the coverage of a limb-threatening wound, requirements for reconstruction could be satisfied only by a second successful tissue transplant. Eighteen of the 54 cases underwent an additional transplantation, with an 89 percent success rate.

Adolescent↗