Analysis of a bulk arrival N-policy queue with two-service genre, breakdown, delayed repair under bernoulli vacation and repeated service policy.

This article deals with an unreliable bulk arrival single server queue rendering two-heterogeneous optional repeated service (THORS) with delayed repair, under Bernoulli Vacation Schedule (BVS) and N-policy. For this model, the joint distribution of the server's state and queue length are derived under both elapsed and remaining times. Further, probability generating function (PGF) of the queue size distribution along with the mean system size of the model are determined for any arbitrary time point and service completion epoch, besides various pivotal system characteristics. A suitable linear cost structure of the underlying model is developed, and with the help of a difference operator, a locally optimal N-policy at a lower cost is obtained. Finally, numerical experiments have been carried out in support of the theory.

Vesico-Salpingo Fistula Masquerading as Hydrosalpinx with Neurogenic Bladder - An Interesting Case Report

A fistula is an abnormal connection between two luminal structures of different epithelium. The majority of urological fistulas in developed countries are consequences of iatrogenic injury most commonly laparoscopic hysterectomies, or from radiotherapy in the treatment of pelvic cancers.1 Contrary to this, most obstetric fistulas in developing countries result from obstructed labour during childbirth.2 Common factors that contribute to obstructed labour in developing countries are delayed presentation after trial labour at home, cephalopelvic disproportion and poor nutrition. Due to prolonged compression by head on the pelvic tissues there happens ischemic necrosis of vagina, bladder neck, and urethra3 called obstructed labour complex. Necrosis and fibrotic healing lead to fistula formation with adjacent structures. The vesicovaginal fistula was the most frequent one (78 %) and the common site involved was trigone (51 %) and based on the level it could be a high or low fistula. Others are vesicouterine fistula, vesicourethral fistula, vesicoureteral fistula and rarely vesico-salpingo fistula. During the acute phase of fistula, tissue oedema, hypovascularity, infection, and nonviable tissue hinder proper tissue healing and hence delayed repair is done after 3 months. Recent literature advises early repair for simple fistulas to reduce patient morbidity and delayed repair of complex fistula, multiple fistulas, infected fistulas, post-radiotherapy, fistula due to foreign bodies, immunocompromised patients, hypoproteinaemia patients, urosepsis patients. 4 Fistula repair is preceded by contrast evaluation of ureter and bladder by CT –IVU and cystogram or MRI followed by cystoscopy or retrograde pyelography. Apart from fistula closure, bilateral ureteric implantation may be needed if ureters are close to the fistula. 5 Abdominal hysterectomy is done in uterovesical fistulas. Huge fistulas close to the bladder neck cannot be repaired without compromising continence hence bladder neck closure is done with the Mitrofanoff procedure. 6 A vesico-salpingo fistula is an abnormal epithelial-lined communication between the urinary bladder and the fallopian tube. This rare type of urogenital fistula has only 7 previously published cases in the literature.

Partial Inferior Pubectomy in the Delayed Repair of Pelvic Fracture Urethral Injury: Adopting a Bone-nibbling Technique

Background: The use of wedge inferior pubectomy can be challenging to many urethral surgeons. Our objective was to introduce a bone-nibbling technique to accomplish a partial inferior pubectomy (PIP) in a resource-poor setting, and to report the medium- to longterm outcome of using the technique. Methods: Five patients were recruited (mean age: 38.8 years) who presented, over a 30-month period, with posterior urethral fibrosis from a pelvic fracture urethral injury (PFUI). One had failed a previous attempt at posterior urethral reconstruction elsewhere. The length of urethral defect was from 2 to 4 cm. We describe a bone-nibbling technique used to carry out PIP for the delayed repair of PFUI in these patients. The outcomes in the medium to long term of surgical procedures done with this technique are presented. Results: Immediate postoperative complications in all were essentially a Clavien–Dindo grade I. Peak flow rate assessed 12 weeks’ post operation was between 20 mL/s and 23 mL/s (mean: 21 mL/s). The longest duration of follow-up was 34 months, and all patients were voiding satisfactorily. Conclusions: A satisfactory and durable outcome can be obtained from nibbling at the bone from the inferior margin of the pubic bone to achieve PIP. This is of interest to lower urinary tract reconstructive surgeons who have concerns with chiseling-out wedge of the inferior pubis. Keywords: Bone nibbling, Partial inferior pubectomy, PFUI, Posterior urethra, Urethral anastomosis

Particle Swarm Optimization and Maximum Entropy Results for MX/G/1 Retrial G-Queue with Delayed Repair

This paper examines an MX/G/1 retrial model with negative customers including the concepts of working vacation, Bernoulli feedback, delayed repair, state-dependent and multi-optional services. Such a queue is quite relevant in real world, for instance in computer systems, manufacturing organisations, packet-switching networks, telecommunication systems, etc. The arrival pattern of customers is according to Poisson distribution. The service is such that first essential service (FES) is provided to every customer and second optional service (SOS) is provided in k phases to those who wants to opt for the same. The negative customers may arrive during the time when the server is busy in serving a positive customer. This leads to breakdown of the server and thus the server has to be restored (repair) by the repair man. Some moments may be taken by the repair man to initiate the repair process, leading to delay in repair. In our work, firstly we have calculated performance measures like long run probabilities and orbit size along with some reliability indices. Then a relative study between the exact expected waiting time and approximate expected waiting time of the system is presented via maximum entropy approach. Also we perform cost optimization using particle swarm optimization (PSO method). Few numerical results are also provided.

Result of delayed repair of quadriceps muscle following a sharp cut injury

We herewith report a case of a 22-year-old man who suffered from a transverse laceration of the quadriceps muscle. The patient presented to us after 3 months of the injury with an inability to extend the knee. We undertook a surgical repair of the muscle tear using the modified Mason-Allen technique and a polypropylene mesh augmentation. To the best of our knowledge, the use of polypropylene mesh for repair augmentation of mid-substance tear of quadriceps muscle has never been described in the literature. The patient had achieved a full active knee extension at 9 months following the surgery. At 3 years of follow-up, the patient has maintained the movements and strength of the knee. He has no functional limitations and is satisfied with the outcome. Thus, the middle term results are good and the treatment is promising.