ABSTRACT
A direct sliding inguinal hernia descends through the superficial inguinal ring and encroaches on nearby organ structures, such as the bladder. This type of hernia is rare with a 2-5% incidence and occurs due to a weakness within the lower abdominal wall, usually associated with advancing age, that permits the distal colon to descend into the inguinal canal. Direct sliding inguinal hernias are a rare subset of inguinal hernias that require meticulous dissection due to their incorporation of nearby organs such as the bladder or colon. Few cases report repair of these hernias laparoscopically; however, the use of a hybrid laparoscopic/open approach has not been extensively documented and it may be beneficial to explore the use of this approach in inguinal hernia repair. We present a case of a robotic-assisted minimally invasive repair of a direct sliding inguinal hernia in an 85-year-old male. He initially presented to the emergency department with left-sided groin pain and imaging revealed he had a direct sliding inguinal hernia that incorporated the bladder wall. He was admitted to surgery for a robotic-assisted minimally invasive inguinal hernia repair with mesh. During the surgery, after seeing the extent at which the hernia sac incorporated the bladder wall, the procedure was converted to an open approach to perform the remainder of the reduction; however the robot was reintroduced for mesh placement. Post-operatively, the patient experienced mild incisional abdominal pain with return of bowel function on day four and was discharged that same day.
ABSTRACT
In this study, the effect of accelerated ultraviolet (UV) aging on the properties of polypropylene (PP) as well as its blend with PP-graft-maleic anhydride (PP-g-MA) and composite with amine-functionalized mullite nanofibers (AMNF) was compared. Solid-state NMR exhibited some changes in the macromolecular chain structure after aging, whereas the formation of degradation products was confirmed through Fourier transform infrared (FTIR) spectroscopy. The aged composite was observed to exhibit the least increment in the crystallinity from X-ray and differential scanning calorimetry (DSC) analyses (0.3 and 0.5%, compared to 9.7 and 10.4%, respectively, for PP) owing to the stability of its amorphous phase against degradation. Similar resistance toward degradation was also confirmed by thermogravimetric analysis (TGA). The surface morphology of the materials also exhibited the lowest extent of surface embrittlement as well as a small number of shallow cracks in the case of a-PP/PP-g-MA/AMNF composite. The aged composite had a much higher impact strength of 14.9 kJ m-2 compared to 2.5 kJ m-2 for aged PP, thus exhibiting its stability against degradation owing to a synergistic combination of the filler and compatibilizer. The optimal performance of the composite was further confirmed through the least extent of reduction in the tensile strength and elongation at break. These findings demonstrate the superior performance of AMNF-reinforced PP composite over PP for outdoor applications.
ABSTRACT
The purpose of this study was to characterize rat adipose-derived stem cells, induce adipose-derived stem cell tenogenesis, and analyze adipose-derived stem cell effects on tendon repair in vivo. Adipose-derived stem cells demonstrated an immunomodulatory, pro-angiogenic, and pro-proliferatory profile in vitro. Tenogenesis was induced for 1, 7, 14, and 21 days with 24 combinations of growth differentiation factor-5, 6, and 7 and platelet-derived growth factor-BB. Adipose-derived stem cells expression of scleraxis and collagen type I increased the most after 14 days of induction with growth differentiation factor-6 and platelet-derived growth factor-BB. Achilles excision defects injected with hydrogel alone (Gp2), with undifferentiated (Gp3) adipose-derived stem cells, or tenogenically differentiated (Gp4) adipose-derived stem cells exhibited improved tissue repair compared with untreated tendons (Gp1). Addition of adipose-derived stem cells improved tissue cytoarchitecture and increased expression of collagen type I and III, scleraxis, and tenomodulin. Adipose-derived stem cells significantly improved biomechanical properties (ultimate load and elastic toughness) over time more than hydrogel alone, while tenogenically differentiated adipose-derived stem cells improved the mean histological score and collagen fiber dispersion range closest to normal tendon. In addition, tendon sections treated with GFP-adipose-derived stem cells exhibited green fluorescence and positive GFP immunostaining on microscopy confirming the in vivo survival of adipose-derived stem cells that were injected into tendon defects to support the effects of adipose-derived stem cells on tissue up to 4.5 weeks post injury.