Deep ocean long range underwater navigation with ocean circulation model corrections.

An underwater navigation algorithm that provides a "cold start" (CSA) geographic position, geo-position, underwater while submerged using travel times measured from a constellation of acoustic sources is described in Mikhalevsky, Sperry, Woolfe, Dzieciuch, and Worcester [J. Acoust. Soc. Am. 147(4), 2365 - 2382 (2020)]. The CSA geo-position is used as the receive position in the ocean for acoustic modeling runs using an ocean general circulation model (GCM). A different geo-position is calculated using adjusted ranges from the travel time offsets between the data and modeled arrival times for each source. Because the CSA geo-position is close to the true position, the source to CSA position propagation model path and the source to true vehicle position data path of the acoustic arrivals are nearly coincident, enabling accurate measurement of travel time offsets. The cold start with model (CSAM) processing reduced the CSA geo-position errors from a mean of 58 to 25 m. A simulation is developed to estimate CSA and CSAM performances as a function of group speed variability between the source paths. The CSAM geolocation accuracy can be calculated from and is controlled by the accuracy of the GCM.

Complex circumferential obstetric fistula-a urologist's worst nightmare.

INTRODUCTION AND HYPOTHESIS: Circumferential vesicourethrovaginal fistula is a severe form of obstetric injury that is challenging to repair and carries a poor prognosis related to eventual continence. Here, we report the successful repair of a circumferential vesicovaginal fistula associated with near total loss of the urethra. The use the anterior bladder flap technique along with an autologous rectus sheath sling resulted in the creation of an effective continence unit. METHODS: A 31-year-old woman had a history of obstructed labor resulting in intrauterine death followed by trans-abdominal hysterectomy for postpartum hemorrhage. Since then she had had total urinary incontinence. She had an attempted repair through the vaginal route, which had failed. Physical examination and endoscopic evaluation revealed a large vesicourethrovaginal fistula with near total loss of the urethra leaving only the meatus. Intraoperatively, we found that it was a large circumferential defect in the infratrigonal region with no anterior bladder wall left at the site of the fistula. RESULTS: We performed an anterior bladder flap procedure as described by Tanagho along with an autologous rectus sheath sling for additional support. Postoperatively, the patient was completely continent. CONCLUSIONS: The anterior bladder onlay flap technique, which has been used extensively for female urethral reconstruction in developed countries, along with an autologous rectus sheath sling is an effective technique for management of circumferential fistulas allowing good continence. Incorporation of this technique into the armamentarium of surgeons managing fistulas in developing countries will go a long way toward helping this unfortunate group of women with this morbid complication of obstructed labor.

Nocturia - Symptom or a Disease?

Waking at night to void is known as nocturia and it is a common condition experienced by both men and women with profound impact on patient's health, quality of life, and economic condition. It is often perceived as a symptom of an organic disease, but the pathophysiology of nocturia is now well-understood, and it is considered as a disease itself. It is classified based on four different pathophysiologic mechanisms (24-hour polyuria, nocturnal polyuria, reduced bladder capacity, and sleep disorders). The association of nocturia with impaired quality of life, cardiovascular morbidity and all-cause mortality is well established. Various pharmacological agents are available, of which desmopressin is considered safe and effective in both short- and long-term studies for the treatment of nocturia in men and women, including the elderly. Combining desmopressin with other agents provides an effective treatment option for nocturia in patients with lower urinary tract symptoms, benign prostatic hypertrophy or overactive bladder syndrome. This review covers the various aspects of pathophysiology and impact of nocturia, as well as the treatment of nocturia. We present the novel concept of a "nocturia clinic", which is a comprehensive diagnostic and management center for patients with nocturia. This set-up may help bring about a positive change in the underreported and undertreated status of nocturia, and bring relief to sufferers of nocturia. Therefore nocturia though perceived as a symptom of many disorders; it itself has a defined pathophysiology and needs treatment.

Role of transurethral resection of the prostate simulators for training in transurethral surgery.

PURPOSE OF REVIEW: Transurethral surgery is an art unique to urologists; mastering the craft is essential for day-to-day practice. Medical treatment along with minimally invasive treatments have significantly reduced the number of transurethral resection of prostates. Decrease in resident's training hours, expanding subspecialties and the emergence of newer technologies have burdened the trainees who are trying to digest the ever-expanding medical literature. Moreover, expectations from patients and insurance companies with a stress on cutting costs and raising litigations have brought changes in apprentice-based to simulator-based training. We studied the role of transurethral resection of prostate simulators in training of transurethral surgery. RECENT FINDINGS: TURP simulators from bench to virtual reality computer models are available. Most of them have undergone face, content and construct validity. Nontechnical skills training is also important hence simulation to simulator training. Simulation programmes incorporating communication, team building, minimizing errors caused by distraction and managing complex situations can turn a novice into an expert with adequate practice in a stress-free environment. Work is also done to define learning curve, and factors affecting the path to reach the desired goal. Concepts are emerging to integrate simulators and simulation into the existing training programmes. SUMMARY: TURP simulators are essential for training in transurethral surgery. Low or high-fidelity simulators do not matter, but having a well structured simulation programme, under the scrutiny of a dedicated trained faculty, will address most of the issues related to training in transurethral surgery, an art essential for urologists irrespective of the subspecialty one pursues in the future.

Warty carcinoma of the penis: A clinicopathological study from South India.

AIMS: There are few studies on the pathology of warty carcinoma (WC) of the penis and these have been from South America. Penile cancers are not uncommon in India. We reviewed the frequency of subtypes of penile squamous carcinoma (SC) and the pathological features and outcome of WC when compared to squamous carcinoma-not otherwise specified (SC-NOS). We also compared the clinicopathological features of WC in our series with those published earlier. MATERIALS AND METHODS: We studied 103 cases of penile cancers over 6 years. Cases were classified into different subtypes according to established histologic criteria. Clinicopathologic features were studied in detail and compared among the different subtypes, especially between WC and SC-NOS. The patients were followed-up and disease free survival in months was noted. RESULTS: SC-NOS constituted 75.7% of all penile cancer cases in our series. The frequency of other subtypes was WC: 9.7%, verrucous: 3.9%, basaloid type and papillary type: 0.97% each, and mixed types 8.7%. The average tumor size and depth of invasion did not differ significantly between the two subtypes. Frequency of lymphovascular emboli and percentage of lymph node metastasis in WC (30 and 10%) were lesser than in SC-NOS (49.37 and 26.58%), respectively. There were no recurrences after partial penectomy in the WC subtype. In the SC-NOS type, three cases had recurrence after partial/total penectomy. CONCLUSION: Warty carcinoma constitutes nearly 10% of all penile squamous cell cancers. These patients seem to have a less aggressive behavior than SC-NOS.

Inferior Vesical Fissure-A Rare Variant of Exstrophy Bladder: Case Report With Literature Review.

Exstrophy variants are uncommon developmental anomalies of the bladder; the variants involving only the bladder neck are extremely rare. There are only three case reports of inferior vesical fissure (IVF) to date, and usually it's uncommonly associated with other malformations. A combination of inferior vesical fistula (IVF) as an exstrophy variant with urethral atresia and anorectal malformation has not been described previously. We report a case of IVF in a 4-year-old male previously operated for anorectal malformation who was managed with fistula closure with bladder neck reconstruction of lay open of stenosed urethra. Recognition of the exstrophy variant is important because the treatment and prognosis are very different.

Redo-urethroplasty in pelvic fracture urethral distraction defect: an audit.

PURPOSE: To predict the outcome of redo-urethroplasty after failed single or multiple open urethral procedures for pelvic fracture urethral distraction defects. METHODS: From January 1997 to December 2006, 43 patients underwent redo-urethroplasty for pelvic fracture urethral distraction defect. Forty-one were referred from other centers. All had undergone open surgery along with an endoscopic procedure (one or more procedures in each patient) which included endoscopic internal urethrotomy, urethral stenting or urethral dilations. RESULTS: There were 43 men with mean age of 29 (range 11-52). Eleven had associated injuries: intraperitoneal bladder rupture (3), bladder neck (2), rectum (3), anal sphincter (2), combined bladder, rectum and anal sphincter (1). Trocar suprapubic cystostomy was performed in 22, rail-road procedures in 10 and open suprapubic cystostomy in 11 along with the management of associated injuries as immediate treatment. Of 43 patients, 28 had progressive perineal, and 12 had transpubic repair. Three patients had total bulbar necrosis, and they underwent prepuceal tube reconstruction (1) and staged substitution with BMG and standard scrotal inlay (2). Analysis of various factors like number of attempts at previous surgery and stricture length did not affect the outcome. A successful result was achieved in 36 (83.72%), improved and stable in five and failure in two. CONCLUSIONS: The overall result of redo-urethroplasty for pelvic fracture urethral distraction defect continues to be gratifying. Failures happen usually within the first 3 months. Substitution urethroplasty can be reserved for those who have long distraction defect. Long-term follow-up is essential using stringent criteria to measure success.

An Unusual Cause of Female Urinary Incontinence Following Obstetric Trauma.

Urethral coitus is a rarely reported cause of female urinary incontinence and has been most commonly described in women with vaginal and hymenal anomalies. Herein, we report a 41-year-old woman with a complex obstetric history, who presented with continuous urinary incontinence. On evaluation, she was found to have an abnormally dilated urethral orifice and vaginal stenosis suggestive of chronic urethral coitus. She underwent a reduction urethroplasty with autologous sling insertion and a vaginoplasty using vaginal flaps. This case highlights the fact that urethral coitus, though rare, should be considered as a cause of urinary incontinence in women with history of obstetric vaginal trauma.

Factors predicting inguinal node metastasis in squamous cell cancer of penis.

PURPOSE: To identify factors predicting the risk of inguinal metastasis in squamous cell carcinoma of the penis. The therapeutic advantages of early lymphadenectomy in squamous cell carcinoma of the penis must be counterbalanced against its post-operative morbidity. Loss to follow up is a major problem in developing countries. Generating a nomogram based on clinical lymph node status and histopathological findings in the primary tumor could facilitate clinical decision making in the management of penile cancer. METHODS: We prospectively studied 106 patients with penile squamous cell cancer treated from September 2001 to August 2007 at our institution. All patients were offered lymphadenectomy (LAD). A multivariate logistic regression model was used to develop a nomogram. We highlight the problems of loss to follow up in these patients. RESULTS: Of 53 who opted for LAD, 22 had nodal metastasis. The presence of high grade (P = 0.004), lymphovascular invasion (LVI) (P = 0.01) and palpable inguinal lymph nodes (P = 0.05) were the strongest predictors of metastasis. Of 51 who refused LAD, 22 were lost to follow up. Out of these, 16 were at high risk and 9 of them came back with inoperable fungating nodes. A nomogram predicting the risk of lymph node metastasis showed a bias corrected good concordance index (0.74) and good calibration. CONCLUSIONS: High grade and LVI in the tumor along with clinical stage of the inguinal nodes were the strongest predictors of metastasis. These features helped us to develop a nomogram to predict and to identify patients at risk of nodal metastasis.

Varicocele: in search of a human model.

AIMS: To study the effects of left gonadal vein ligation on semen parameters and venous hemodynamics of the testis. SUBJECTS AND METHODS: All male voluntary kidney donors who were scheduled to have left donor nephrectomy between March 2004 and February 2005, by either open or laparoscopic technique, were considered for this study. RESULTS: A total of 95 live related renal transplants were performed. Left donor nephrectomy was performed in 22 of 37 males. Only 19 were evaluable; 7 patients underwent laparoscopic donor nephrectomy; 6 were unmarried. We observed that 66% (12) of our study patients showed radiological evidence of varicocele, and this was statistically significant; 22% (4) also developed contralateral varicocele; 44% (8) developed oligoasthenozoospermia. CONCLUSION: Ligation of the left gonadal vein is part of organ harvesting for live related renal transplantation and produces radiologically confirmed varicocele in some men. In these men, alterations in semen parameters are observed over 4-24 weeks. Due to short follow-up, we are unable to state if this is a permanent or temporary effect. We presume that since these men had normal semen parameters earlier, the stress pattern would revert to normal. If it does not however, this would have particular implications upon informed consent for unmarried male donors.

Late occurrence of pelvi-ureteric junction obstruction in renal allograft and live-related kidney donor.

Pelvi-ureteric junction (PUJ) obstruction is an enigmatic condition. While in a reasonable majority it is clear cut, the diagnosis and the need for intervention in the remainder is still a challenge. We would like to share the details of two cases, one in a transplant recipient and the other in a living kidney donor, and propose an explanation as to why PUJ obstruction becomes manifest after such a long period of time. In this presentation, we would like to propose that forced drinking of fluids by patients who have an equivocal PUJ and a single kidney could tilt the balance resulting in overt PUJ obstruction.

Outcome following renal autotransplantation in renal artery stenosis.

INTRODUCTION: With significant advances in the area of interventional radiology, angioplasty and stenting have become preferred first-line treatment in patients with significant renal artery stenosis. However, not all patients have favorable anatomy to undergo minimally invasive treatments, and reconstruction of the renal artery is an option. In select cases, either improved renal function or maintenance of existing function and sometimes resolution of hypertension can follow surgical treatment. MATERIAL AND METHODS: This was a prospective observational study conducted from August 2010 to June 2016. Patients <45 years of age with uncontrolled hypertension secondary to renovascular hypertension (RVH) and refractory to medical management and renal arterial disease unfavorable for percutaneous intervention were included in the study. All patients were evaluated thoroughly using computed tomography angiography and diethylenetriaminepentaacetic acid renal scan. Patients underwent autotransplantation either into the right or left iliac fossa. Some kidneys required bench reconstruction of the renal artery and/or its branches before being implanted into either iliac fossa. RESULTS: Nine patients were included in the study. The mean age was 27 years. Seven were males and two were females. Five patients had bilateral renal artery stenosis. After autotransplantation, initially five patients became free of antihypertensive medicines, but on the follow-up, two patients showed rising trend of blood pressure. The evaluation revealed narrowing at anastomosis site in both patients with salvageable kidney function in one patient. Angioplasty with stenting was done in this patient while the second patient underwent secondary nephrectomy. At 2 years of follow-up, four patients required no antihypertensive medicines. CONCLUSION: Autotransplantation can be a successful treatment of severe RVH and should be considered in patients with renal arterial disease unfavorable for percutaneous intervention.

An in vitro study on human ureteric smooth muscle with the alpha1-adrenoceptor subtype blocker, tamsulosin.

OBJECTIVE: To study the effects of tamsulosin on ureteric contractions and its effects on the basal tone of human ureteric specimens, as clinical trials with tamsulosin have shown promising results in the spontaneous expulsion of lower ureteric calculus, but the mechanism of action of tamsulosin in the expulsion of ureteric calculus has not been elucidated in in-vitro studies on human ureters. MATERIALS AND METHODS: Human mid-ureteric specimens were obtained from live kidney donors. The specimen was transported in Krebs' solution and the isometric contraction of human ureteric smooth muscle was recorded in the presence of tamsulosin. Ureteric rings from 19 kidney donors were studied. RESULTS: At 100 microm tamsulosin the frequency of ureteric contraction was blocked completely, or the contraction frequency was reduced in 89% of specimens. There was no change in the frequency or in the amplitude of contraction in the remaining specimens. The basal tone of the ureter was reduced in 16% of the specimens. CONCLUSION: Our results suggest that peristaltic activity in human ureteric smooth muscle is inhibited by tamsulosin. The effect of tamsulosin on basal tone is marginal.

Comparative study of graft nephrectomy in pre-cyclosporine and cyclosporine era.

OBJECTIVE: To assess the incidence and identify the indications for graft nephrectomy (GN) in the cyclosporine (CSA) era as compared to GN in the pre-CSA era. MATERIALS AND METHODS: This is a retrospective study of 1,866 renal transplants done from 1971 to 1999. 675 were transplanted in the pre-CSA era (group 1) and 1,191 in the CSA era (group 2). The published series on experience with GN in the pre-CSA era was compared with that in the CSA era. GN done within 6 months of transplant was defined as early GN and those done after 6 months were included under late GN. The incidence, indication and the implications of GN were studied and compared with our experience in the pre-CSA era. Results were analyzed using the chi(2) test. RESULTS: Of the 675 transplants in group 1, thirty-one had GN compared to 15 of 1,191 in group 2. There was a significant decrease in GN in the CSA era. Of the 31 in group 1, thirty had early GN as compared to 6 of 15 in group 2 (p = 0.003). On the contrary, late GN was significantly higher in group 2 (9/15) as compared to group 1 (1/31). Acute rejections and graft infections were the predominant causes of graft loss in group 1, while late graft loss due to symptomatic chronic rejection was the commonest cause in group 2. Morbidity was equal in both groups while mortality was significantly higher in group 1. CONCLUSION: CSA has significantly reduced the need for GN. By reducing hyper, acute, and irreversible acute rejection, the need for early GN has also been reduced significantly. Though there is an increased incidence of chronic allograft nephropathy, late GN is indicated only when there is refractory hematuria, intractable proteinuria and graft sepsis. With better immunosuppression, graft loss secondary to infection has decreased and mortality due to GN has been minimized.

Surgical management of renal tuberculosis.

Tuberculosis (TB) is one of the major health problems that our country is facing today. Despite active interventions by our government, control of TB still remains to be achieved. The emergence and exponential growth of the human immunodeficiency virus and drug-resistant strains threaten to further complicate the TB situation in our country. Even in this era of advanced chemotherapy, many lives are lost every day in our country. Tuberculosis of the urinary tract, despite being one of the commonest forms of extra-pulmonary TB, is generally overlooked. Most patients present with vague lower urinary symptoms typical of urinary tract infection. In this article, we shall highlight the various issues related to the surgical management of renal and ureteral tuberculosis.

Youssef's syndrome: Is there a better way to diagnose?

Vesicouterine fistula (VUF) the least common of the urogynecological fistulae. Hysterosalphingography is the gold standard investigation in demonstrating the fistulous track. It is an invasive investigation. We report a case of VUF where magnetic resonance imaging was useful to diagnose the condition in a non-invasive manner especially when the clinical picture was confusing.

Effect of hypospadias on sexual function and reproduction.

Hypospadias is a highly prevalent congenital anomaly. The impact of the defect and operative interventions on sexual and reproductive function has been addressed by few publications. It is essential to know the possible outcomes of intervention for appropriate counseling, operative planning, and follow-up. English articles indexed in Pubmed dealing with the long-term sexual and reproductive outcome following hypospadias repair from 1965 to 2007 were reviewed. To our knowledge, there was no prospective trial comparing the impact of various techniques on sexual outcome. There is considerable discordance in literature regarding the effects on sexual function. A few publications report patient and partner dissatisfaction with the appearance of genitalia. Sexual dissatisfaction is often attributed to penile size. Ejaculatory disturbances range between 6 and 37% of operated individuals. There is no convincing evidence for impaired fertility. The long-term follow-up is essential to identify problems and to address them appropriately. Literature documenting the outcome of specific operative procedures and analysis based on severity of hypospadias will be informative. The long-term follow-up of the newer techniques which are more commonly used are awaited.

A cost comparison of open versus percutaneous approaches to management of large staghorn calculi.

AIM: This paper compares the cost of open versus percutaneous approaches to the management of large staghorn calculi in a tertiary care hospital in India. MATERIALS AND METHODS: Patients who underwent surgery for staghorn calculi larger than 6 cm between January 1998 and December 2003 were included. Those who had confounding factors in terms of cost such as additional surgical or medical procedures and complications unrelated to the surgery were excluded. The process of costing was done by following the clinical pathway. RESULTS: There were 13 patients who had open stone surgery and 19 patients who underwent percutaneous nephrolithotripsy (PCNL). The major differences in cost were seen in the higher cost of instruments and consumables in the PCNL group. The cost of management of complications widened this gap. Two patients in the PCNL group and none in the residual group required redo surgery. The residual stones in the open and PCNL groups required a mean of 2525 and 3623 shocks per patient respectively. Complete clearance after redo surgery and Shockwave lithotripsy (SWL) was seen in 92% and 58% in the open and PCNL arms respectively. The overall cost per patient was $625 per PCNL and $499 per open surgery. The final mean residual stone size in the PCNL group was 4.84 mm whereas it was 0.38 mm in the open group. The effective cost of achieving complete clearance in one patient was $1078 in the PCNL group and $543 in the open group. CONCLUSION: Open stone surgery is less costly than PCNL in large staghorn calculi.

Histopathological analysis of T1 renal cell carcinoma: Does presentation matter?

OBJECTIVES: To study the differences in the clinico-pathological features of incidental and symptomatic T1 renal cell carcinoma (RCC) and to see, particularly in T1b RCC, if symptomatic presentation has adverse pathological features concerning the oncological safety of elective nephron-sparing surgery (NSS) in this subgroup. MATERIALS AND METHODS: Of 278 patients who underwent radical nephrectomy for RCC from January 1995 to January 2005, 70 had tumor size up to 7 cm (T1). They were categorized as incidental or symptomatic and as T1a or T1b tumors. Clinico-pathological features were compared between incidental (IRCC) and symptomatic (SRCC) groups. Tumors were analyzed using the 1997 TNM staging and Fuhrman's grade. RESULTS: Of the 70 with T1 tumors, 24 had T1a (IRCC, 12 and SRCC, 12) and 46 had T1b tumors (IRCC, 27 and SRCC, 19). Clear cell was the commonest histology. In T1a cancers, though no significant difference in histopathological pattern and grade was seen between the incidental and symptomatic groups, symptomatic tumors had more papillary, mixed histopathological pattern and higher nuclear grade. Among T1b tumors, 14 had papillary and mixed histology, 12 (86%) of which were symptomatic (P= <0.0001). In T1b, 15 (79%) symptomatic had higher nuclear grade (G2-3) while 22 (81%) incidental had lower Fuhrman's grade (P= <0.0001). CONCLUSION: Symptomatic T1b RCCs had higher nuclear grade and papillary histology. This difference was statistically significant. This may be relevant when considering elective NSS in symptomatic T1b disease.