Wavefronts and modal structure of long surface and internal ring waves on a parallel shear current

We study long surface and internal ring waves propagating in a stratified fluid over a parallel shear current. The far-field modal and amplitude equations for the ring waves are presented in dimensional form. We re-derive the modal equations from the formulation for plane waves tangent to the ring wave, which opens a way to obtaining important characteristics of the ring waves (group speed, wave action conservation law) and to constructing more general ‘hybrid solutions’ consisting of a part of a ring wave and two tangent plane waves. The modal equations constitute a new spectral problem, and are analysed for a number of examples of surface ring waves in a homogeneous fluid and internal ring waves in a stratified fluid. Detailed analysis is developed for the case of a two-layered fluid with a linear shear current where we study their wavefronts and two-dimensional modal structure. Comparisons are made between the modal functions (i.e. eigenfunctions of the relevant spectral problems) for the surface waves in homogeneous and two-layered fluids, as well as the interfacial waves described exactly and in the rigid-lid approximation. We also analyse the wavefronts of surface and interfacial waves for a large family of power-law upper-layer currents, which can be used to model wind generated currents, river inflows and exchange flows in straits. Global and local measures of the deformation of wavefronts are introduced and evaluated.

Abdominoscrotal Hematocele in an Adult and Its Successful Treatment

Abdominoscrotal hydrocele (ASH) is a variant of hydrocele rare to occur in adults. ASH has two sacs, one in the scrotum and one in the abdomen connected through the inguinal canal. Abdominoscrotal hematocele is a rare complication of ASH. We present a 57-year-old male patient, presented to us in August 2019 to JIPMER, Puducherry, India, with complaints of swelling in the scrotum for 15years and abdominal pain for two months. Both the swellings were soft, and cross fluctuation was present. Imaging confirmed the diagnosis of ASH. We did diagnostic laparoscopy, and the abdominal sac was decompressed and found to have thick brownish fluid suggestive of hematocele. We could demonstrate that both sacs were connected. Due to difficulty in the dissection of the sac, the procedure was converted to an open procedure. Both the sacs were excised, and Lytle’s repair was done for the dilated internal ring. Keywords: Testicular Hydrocele, Scrotal Hydrocele, Hydrocele, Hematocele, Testicular Hematocele, Scrotal Hematoceles, Laparoscopic Surgical Procedure, Laparoscopic Surgery

Learning Curve for Laparoscopic Repair of Pediatric Inguinal Hernia Using Percutaneous Internal Ring Suturing

Background: Percutaneous internal ring suturing (PIRS) is a simple and popular technique for the treatment of inguinal hernia in children. The aim of this study was to analyze the learning curves during implementation of PIRS in our department. Methods: A total of 318 pediatric patients underwent hernia repair using the PIRS technique by three pediatric surgeons with different levels of experience in laparoscopic surgery. These patients were enrolled in a prospective cohort study during the period October 2015–January 2021. Surgical times, intraoperative and postoperative complications, in addition to outcomes of treatment were compared among the pediatric surgeons. Results: Regarding operative time a significant difference among the surgeons was found. Operative time significantly decreased after 25–30 procedures per surgeon. The surgeon with advanced experience in laparoscopic surgery had significantly less operative times for both unilateral (12 (interquartile range, IQR 10.5, 16.5) min vs. 21 (IQR 16.5, 28) min and 25 (IQR 21.5, 30) min; p = 0.002) and bilateral (19 (IQR 14, 21) min vs. 28 (IQR 25, 33) min and 31 (IQR 24, 36) min; p = 0.0001) hernia repair, compared to the other two surgeons. Perioperative complications, conversion, and ipsilateral recurrence rates were higher at the beginning, reaching the benchmarks when each surgeon performed at least 30 PIRS procedures. The most experienced surgeon had the lowest number of complications (1.4%) and needed a fewer number of cases to reach the plateau. The other two surgeons with less experience in laparoscopic surgery had higher rates of complications (4.4% and 5.4%) and needed a higher number of cases to reach the plateau (p = 0.190). Conclusions: A PIRS learning curve for perioperative and postoperative complications, recurrences, and conversion rates reached the plateau after each surgeon had performed at least 30 cases. After that number of cases PIRS is a safe and effective approach for pediatric hernia repair. A surgeon with an advanced level of experience in pediatric laparoscopic surgery adopted the technique more easily and had a significantly faster learning curve.