Cremaster muscle thickening: the anatomic difference in men with testicular retraction due to hyperactive cremaster muscle reflex

The objective was to assess whether men suffering from testicular retraction secondary to hyperactive cremaster muscle reflex have an anatomic difference in the thickness of the cremaster muscle in comparison to men who do not have retraction. From March 2021 to December 2021, 21 men underwent microsurgical subinguinal cremaster muscle release (MSCMR) on 33 spermatic cord units, as 12 of them had bilateral surgery, at Surgicare of South Austin Ambulatory Surgery Center in Austin, TX, USA. During that same time frame, 36 men underwent subinguinal microsurgical varicocele repair on 41 spermatic cord units, as 5 were bilateral for infertility. The thickness of cremaster muscles was measured by the operating surgeon in men undergoing MSCMR and varicocele repair. Comparison was made between the cremaster muscle thickness in men with testicular retraction due to a hyperactive cremaster muscle reflex undergoing MSCMR and the cremaster muscle thickness in men undergoing varicocele repair for infertility with no history of testicular retraction, which served as an anatomic control. The mean cremaster muscle thickness in men who underwent MSCMR was significantly greater than those undergoing varicocele repair for infertility, with a mean cremaster muscle thickness of 3.9 (standard deviation [s.d.]: 1.2) mm vs 1.0 (s.d.: 0.4) mm, respectively. Men with testicular retraction secondary to a hyperactive cremaster muscle reflex demonstrate thicker cremaster muscles than controls, those undergoing varicocele repair. An anatomic difference may be a beginning to understanding the pathology in men who struggle with testicular retraction.

In vivo comparison of two enteric-pouch power transformers for circulatory support

A defunctionalized ileal pouch is thin-walled (1-2 mm), well perfused (blood flow, 0.3-1.0 ml/g/min), and tactile-insensitive. If fixed within the abdominal wall and provided with a miniature stoma for primary wire entry, the heat dissipating capacity and achievable geometries could facilitate small efficient intra- to extracorporeal power transformers with virtually complete magnetic flux containment. Two transformers (A, weighing 102 gm with dual ferrite cores, intraluminal primary and extraluminal secondary each with 10 turns on its own crescentic ferrite core, 90 kHz, coupling coefficient k = 0.90-0.96; and B, 68 gm, a single flexible torroidal magnetic metallic tape core with attached 11 turn primary and free 14 turn serosal secondary, 14.7 kHz, k = 0.99) met the electrical and anatomic requirements. Each was implanted (minilaparotomy, coil-pouch fixation within abdominal musculature) in 4 dogs for 14-21 days to test the operative feasibility, electrical function, warming, and flux containment. For canine testing, wires were tunneled to a chewing-inaccessible site. Neither tissue necrosis, infection, provokable interference from contiguous metal, nor coil displacement were observed; secretions were retained in Group A pouches only. The mean power transmissions for the transformers were A: 24.90 +/- 1.50 W and B: 24.92 +/- 0.89 W, after operation for 7 days or more. The mean efficiencies were A: 75.6 +/- 0.1% total DC/DC, 96.2% coils and B: 80.4 +/- 0.1% total DC/DC, 96.2% coils. The peak skin surface magnetic fluxes for transformers A and B, both trivial at 1.7 and 1.2 G, respectively, were similar. Warming was 0.62 +/- 0.30 degrees C in Group A and 0.73 +/- 0.19 degrees C in Group B. The probability values were p < 0.5 (NS) for DC/DC efficiency and p > 0.10 (NS), for A versus B in all other areas of comparison. Observations for both were encouraging. Transformer B, with less mass, lower frequency, higher efficiency, and intrinsic invulnerability to displacement, was selected for longer term evaluation.

Development of a high permeability cored transintegumental power transformer

Circulatory support devices require 10-20 W. Currently, several devices are under development for the transmission of this power via transcutaneous transformers, with the secondary implanted subcutaneously and the primary worn externally. Because these devices are air cored, they have relatively large, bulky external appliances, poor coil to coil coupling, and result in significant stray fields passing through adjacent tissues. This article reports on the engineering design of a novel, high permeability cored transformer implanted in a transenteric configuration using an isolated intestinal pouch. Such an approach offers greater energy transmission efficiency, less heat dissipation, less stray electromagnetic energy, and greatly reduced device size. Two competing designs using this concept have been developed and tested. Each consists of the transformer, together with power interface electronics, forming a direct current (DC)/DC resonant converter. Operating frequencies are 90.2 and 14.7 kHz, respectively, with primary/secondary turns ratios of 10/10 and 11/14, respectively. In addition, data interface electronics allows communication across the transformer of up to four signals at a per channel sample rate of 10 Hz. Both designs are able to continuously transmit 25 W at an output level of 12 Vdc into a 5.8 omega load. Calorimetry tests indicate DC to DC efficiencies greater than 75% and coil to coil efficiencies greater than 96%. Total package size for the implantable portion of each device (including sensor internal interface electronics) is less than 40 ml, with a weight weight of less than 100 g. The results of short-term implantation studies have been favorable. Long-term implantation studies currently are under way.