Artifact reduction in undersampled projection reconstruction MRI of the peripheral vessels using selective excitation.

The projection reconstruction (PR)-HyperTRICKS (time resolved imaging of contrast kinetics) acquisition integrates the benefits of through-plane Cartesian slice encoding and in-plane undersampled PR. It provides high spatial resolution both in-plane (about 1 mm(2)) and through-plane (1-2 mm), as well as relatively high temporal resolution (about 0.25 frames per second). However, undersampling artifacts that originate from anatomy superior or inferior to a coronal imaging FOV may severely degrade the image quality. In coronal MRA acquisitions, the slice coverage is limited in order to achieve high temporal resolution. In this report we describe an artifact reduction method that uses selective excitation in PR-HyperTRICKS. This technique significantly reduces undersampling streak artifacts while it increases the slice coverage.

Microvascular free-tissue transfers in elderly patients: the leeds experience.

Free-tissue transfer in the elderly has received increasing attention in the literature. Existing reports are limited by small samples or inadequate definition of the term elderly. This study reviewed 5 years' experience with free-tissue transfer in a geriatric population (mean age 75 years, range 70 to 83 years). Forty-nine free flaps were performed in 42 patients between 1986 and 1991. This review focuses on the 39 flaps undertaken in 33 head and neck cancer patients, the main indication being reconstruction after tumor resection (80 percent). In the head and neck cancer group, donor sites included the radial forearm (20), rectus abdominis (6), jejunum (5), and others (8). Thirty-four flaps (87 percent) were primarily successful. Reexploration was required in 10 patients (26 percent) for compromised flaps (5) and bleeding (5). Three of the compromised flaps were salvaged, giving an overall flap success rate of 95 percent. One patient (3 percent) died within 30 days of surgery. These results compare favorably with other published series in elderly patients, as well as with larger cohorts of younger subjects. Free flaps are safe in the elderly. Chronologic age alone should not be an exclusion criterion when selecting patients for free-tissue transfer.

Transcranial erosion of a benign dermal cylindroma.

Dermal eccrine cylindroma is a benign adnexal tumor that commonly affects the scalp, neck, and face. Malignant transformation is rare and has resulted in several cases of intracranial invasion. There have been no previously reported cases of a benign lesion eroding through the skull vault. We report the development of such a lesion in a woman who had undergone total scalp excision and resurfacing with a split skin graft some 23 years earlier. Details of the case and its management are presented.

A skin model for wound closure tuition.

An easy to make skin model has been developed using commonly available materials. It allows simple wound closure to be practised safely on a medium which attempts to simulate the properties of soft tissue.

Experience with the Fowler Stephens and microvascular procedures in the management of intraabdominal testes.

The Fowler Stephens operation and microvascular procedures were compared for the management of 23 intra-abdominal testes in 15 boys, 7 of whom had the prune belly syndrome. The Fowler Stephens operation was used for 15 testes (4 single-stage and 11 two-stage) and microvascular transfer was used for 8 testes. Eleven testes treated by the Fowler Stephens procedure (73%) and 7 treated by microvascular procedures (88%) were viable and intrascrotal after an average follow-up of 3.0 years, giving an overall success rate of 78%. Eight of 9 post-pubertal testes were biopsied. Severe maturational arrest was evident in all and carcinoma in situ was present in one.

Short-term effects of calcium antagonists on hemodynamics and cyclosporine pharmacokinetics in heart-transplant and kidney-transplant patients.

Effects of two calcium antagonists on hemodynamics and on cyclosporine pharmacokinetics were studied in eight transplant patients (four heart-transplant and four kidney-transplant patients) by use of a single-blind, randomized, crossover, and placebo-controlled design. Patients received, at least 1 week apart, either 90 mg diltiazem, 20 mg nifedipine (in tablet form), or placebo, given 1 hour before cyclosporine. Cyclosporine and its main metabolite (metabolite 17) were measured in plasma (separated at 25 degrees C) by use of HPLC. Both calcium antagonists tended to increase absorption rate and elimination rate, but none of the pharmacokinetic parameters of cyclosporine were significantly altered. Moreover, the area under the curve of plasma concentrations of metabolite 17 did not change. On the other hand, both nifedipine and diltiazem significantly altered the hemodynamics, but to a different extent in the two groups of patients. The heart-transplant patients showed larger decreases in systolic and diastolic blood pressure than the kidney-transplant patients after administration of both nifedipine and diltiazem, but they showed smaller increases in cardiac index and heart rate with nifedipine. In contrast, diltiazem caused small decreases in heart rate and cardiac index in heart-transplant patients and small increases in heart rate and cardiac index in kidney-transplant patients. We conclude that a single dose of either nifedipine or diltiazem does not affect, to a clinically significant extent, the pharmacokinetics of cyclosporine. In addition, heart-transplant patients show different hemodynamic responses to these two calcium antagonists than the responses shown by kidney-transplant patients, probably because of cardiac denervation.

Segmental microvenous graft to artery.

One hundred and five microvenous grafts were carried out during three periods of time. Forty-five were performed in 1971, 25 were performed in 1975 and 35 were performed in 1979. The rabbits weighed 2 to 2.5 kg and a standard technique was followed by inserting a 1 cm vein graft after creating a defect of 0.5 cm in the femoral artery, taking the graft from the femoral vein on the same side. Exploration was carried out from 1 to 21 weeks at weekly intervals. The patency rate in Series I (1971) was 71 per cent, whereas the patency rate in Series II (1975) was 96 per cent and in Series III (1979) was 100 per cent. The scanning electron microscope showed that in the short term there was no narrowing of the lumen, nor any microaneurysm formation as reported previously by Buchler and Buncke (1979).

Scalp and cranial substitution with autotransplanted greater omentum using microvascular anastomosis.

A case is described whereby a large defect of scalp and cranium was successfully covered using autotransplanted greater omentum, revascularized by microsurgical techniques.

Microvascular second toe transfer for digital reconstruction.

Reconstruction of a severely damaged hand, with multiple amputations of digits, presents a difficult reconstructive problem. The development of a safe method of transfer of the great toe for thumb reconstruction, using the dorsalis pedis artery and the saphenous vein, suggested the possibility of one-stage microvascular transfer of the second toe for reconstruction of fingers. In two patients a one-stage transfer of the second toe was done to replace an index finger and in another for restoration of part of the left ring finger. The transplants survived without anticoagulants and vessel complications were not encountered. Sensory return was adequate and a significant improvement in function was achieved.

Microlymphaticovenous anastomoses for obstructive lymphedema.

Microlymphatic surgery appears to have a worthwhile clinical application in the treatment of secondary obstructive lymphedema. We prefer 3 or more lymphaticovenous anastomoses at, or above, the elbow; otherwise ablative procedures are recommended. In the selected cases there are some advantages of anastomoses over surgical reduction procedures: (1) the incidence of postoperative cellulitis is significantly less; (2) the microlymphatic techniques are applicable to both upper and lower limbs and perhaps could be extended to localized cases of obstructive lymphedema following trauma and congenital constriction bands. Considerable experience in microvascular surgery is required for doing this type of work. A long-term evaluation of the results of microlymphatic surgery in obstructive secondary lymphedema is required before judging its potential--especially in view of the fluctuating history of lymphedema--but the results reported are encouraging.