Progressive surgical dissection for tendon transposition affects length-force characteristics of rat flexor carpi ulnaris muscle

Abstract Extramuscular connective tissue and muscular fascia have been suggested to form a myo-fascial pathway for transmission of forces over a joint that is additional to the generally accepted myo-tendinous pathway. The consequences of myo-fascial force transmission for the outcome of conventional muscle tendon transfer surgery has not been studied as yet. To test the hypothesis that surgical dissection of a muscle will affect its length-force characteristics, a study was undertaken in adult male Wistar rats. During progressive dissection of the flexor carpi ulnaris muscle, isometric length-force characteristics were measured using maximal electrical stimulation of the ulnar nerve. After fasciotomy, muscle active force decreased by approximately 20%. Further dissection resulted in additional decline of muscle active force by another 40% at maximal dissection. The muscle length at which the muscle produced maximum active force increased by approximately 0.7 mm (i.e. 14% of the measured length range) after dissection. It is concluded that, in rats, the fascia surrounding the flexor carpi ulnaris muscle is a major determinant of muscle length-force characteristics.

The submarine Congo Canyon as a conduit for microplastics to the deep sea

The increasing plastic pollution of the world’s oceans represents a serious threat to marine ecosystems and has become a well-known topic garnering growing public attention. The global input of plastic waste into the oceans is estimated to be approximately 10 million tons per year and predicted to rise by one order of magnitude by 2025. More than 90% of the plastic that enters the oceans is thought to end up on the seafloor, and seafloor sediment samples show that plastics are concentrated in confined morphologies and sedimentary environments such as submarine canyons. These canyons are occasionally flushed by powerful gravity-driven sediment flows called turbidity currents, which transport vast volumes of sediment to the deep sea and deposit sediment in deep-sea fans. As such, turbidity currents may also transport plastics present in the canyon and bury plastics in deep-sea fans. These fans may therefore act as sinks for seafloor plastics. Here we present a comprehensive dataset showing the spatial distribution of microplastics in seafloor sediments from the Congo Canyon, offshore West Africa. Multicores taken from 16 locations along the canyon, sampled different sedimentary sub-environments including the canyon thalweg, canyon terraces, and distal lobe. Microplastics were extracted from the sediments by density separation and the polymer type, size, and shape of all individual microplastic particles were analysed using laser-direct infrared-spectroscopy (LDIR). Microplastic number concentrations in the sediments of the distal lobe are significantly higher than in the canyon, indicating that the Congo Canyon system is a highly efficient conduit for microplastic transport to the deep sea. Moreover, microplastic concentrations of >20,000 particles per kg of dry sediment were recorded in the lobe, which represent some of the highest ever recorded microplastic number concentrations in seafloor sediments. This shows that deep-sea fans can serve as hotspots and potential terminal sinks for seafloor microplastics

Metaidoioplasty: an alternative phalloplasty technique in transsexuals

The various techniques for phalloplastv in female-to-male transsexuals produce results that are more or less acceptable, both aesthetically and functionally. However, all these techniques will lead to extensive scarring of the donor area. Metiadoplasty uses the clitoris, overdeveloped by hormonal treatment, to construct a microphallus in a way comparable to the correction of chordae and lengthening urethra in male pseudohermaphrodites and in cases of severe hyposaidias. It will not leave any scars outside the genital area. My experience in 32 female-to-male transsexuals is presented. At best, metaidoplastv will provide a small phallus, if at all, capable of sexual penetration. Still, I consider it to be a method of choice in cases where the clitoris seems large enough to provide a phallus that will satisfy the patient. (Plast. Reconstr. .Surg. 97: 161, 1996.

Free-flap distal arteriovenous fistula : when to close it?

A distal arteriovenous fistula was created secondarily in an innervated radial forearm Free flap, to salvage the neophallus in three female-to-male transsexuals. This resulted in permanent edema and an arterial thrill in the neophallus. The arteriovenous fistulas were closed after 6 weeks to 20 months. Acute endothelial damage with risk of thrombosis, due to ischemia and exposure to arterial blood pressure, may be expected to have been repaired 4 to 6 weeks after arterialization of the veins. intimal thickening will have started by then, but a subsequent decrease in vascular luminal diameter may still be expected to be reversible. The authors conclude that ligation of the distal arteriovenous fistula may safely be performed some 6 weeks after the salvage procedure

Compression of the deep branch of the ulnar nerve due to volar dislocation of the fifth carpometacarpal joint

Volar dislocation of the base of the fifth metacarpal bone is an unusual event. When it occurs, damage to the deep branch of the ulnar nerve may be expected because of its close relation to the carpometacarpal joint. A case of neuropathy of the deep ulnar motor branch due to such a dislocation is reported. Mild wasting of the first dorsal interosseous muscle and a severe loss of adduction strength of the thumb was observed 7 weeks after reduction of the dislocation. Complete functional recovery occurred 4 months after the initial injury

Reconstruction of Acquired Perineovulvar Defects: A Proposal of Sequence

Acquired perineovulvar defects are usually the result of excision of vulvar intraepithelial neoplasia (VIN) or invasive squamous cell carcinoma. Because both VIN and vulvar carcinoma have a tendency toward local recurrence, future reconstructive options should be reckoned with during treatment of the primary and all subsequent (pre-) malignant perineovulvar lesions. Hence, a proposal of sequence of reconstructive options for these defects is called for. In cases where local skin flaps suffice, these are preferably designed in such a fashion as not to sever the branches of the internal pudendal vascular system. In cases where either a pudendal thigh flap or an infragluteal flap may be used to close the perineovulvar defect, the pudendal thigh flap is to be preferred to preserve the infragluteal flap for future use. Only when these flaps no longer are available or sufficient to cover the defect should the gluteal thigh flap be applied. The use of myocutaneous flaps is rarely indicated to close isolated superficial perineovulvar defects

Life Span of Silicone Gel-Filled Mammary Prostheses

The discussion on possible side effects of implanted silicone has resulted in a growing number of patients inquiring whether or not their mammary prostheses are intact and when failure of the prostheses is to be expected. Between November 1988 and May 1995, 182 patients had their silicone mammary prostheses replaced, repositioned, or removed one to three times. Capsular contraction, dislocation, pain paresthesia, and/or suspected rupture were common indications for surgery. To try and be able to provide an indication as to the correlation of implant age and integrity, we recorded the status of all 426 prostheses observed during secondary surgery. In this selected group of patients, approximately 50 percent of the mammary prostheses with an implant age of 7 to 10 years showed gel bleed or rupture. Applying the survival Kaplan-Meier curve, 50 percent of implants may be expected to bleed or be ruptured at the age of 15 years. Rupture was observed more frequently than gel bleed. It seems that there is no chronologic relation between gel bleed and rupture

The truly distal lateral arm flap: rationale and risk factors of a microsurgical workhorse in 30 patients

The forearm part of the extended lateral arm flap may be separately raised on the most distal septocutaneous perforator of the posterior collateral radial artery. This truly distal lateral arm flap shares most of the advantages of the radial forearm flap and is associated with less donor site morbidity. From April 2000 to March 2004, we used 30 such flaps as the fasciocutaneous free flap of choice, mostly for reconstructions in the head and neck region. The eventful postoperative course observed in 5 of these flaps motivated us to evaluate the rationale and risk factors of this procedure. We prospectively analyzed the influence on the incidence of partial or complete flap loss of 19 patient-related or procedure-related characteristics that may have acted as risk factors. None were found to be of statistical significance. We found the distal lateral arm flap to have a less robust vascular anatomy than the radial forearm flap, resulting in the need for advanced surgical expertise to raise and handle it. As we recognized the difficulty of this flap to be associated predominantly with this anatomy of its vascular pedicle, we now take a more liberal stand toward the possibility of intraoperative conversion to the use of a radial forearm fla