Urinary Diversion: Core Curriculum 2021

Urinary diversion after cystectomy has been a historical standard for the treatment of numerous benign and malignant diseases bladder. Since first published description in early 1900s, improvements surgical technique better understanding metabolic sequelae postoperatively have greatly enhanced patient outcomes. Both continent incontinent diversions are available to patients cystectomy. In appropriately selected patients, orthotopic neobladder reconstruction can offer preservation body image continence, cutaneous represent reasonable alternative. Conduit diversion, which remains most commonly performed technique, is ideal who would benefit from less morbid procedure that negates need self-catheterization. This installment Core Curriculum Nephrology outlines aspects urinary multidisciplinary approach postoperative management at intersection nephrology urology required effectively optimize article includes discussion various reconstructive options as well comprehensive review frequently encountered short-term long-term abnormalities associated with altered electrolyte acid-base homeostasis. FEATURE EDITORAsghar RastegarADVISORY BOARDUrsula C. BrewsterMichael ChoiAnn O’HareBiff F. PalmerThe aims give trainees strong knowledge base core topics specialty by providing an overview topic citing key references, including foundational literature led current clinical approaches. EDITOR Asghar Rastegar ADVISORY BOARD Ursula Brewster Michael Choi Ann O’Hare Biff Palmer The revolutionized paradigm both tract since its conception over 150 years ago. A normally functioning bladder, simplest sense, highly compliant reservoir storage urine low pressures. When physiologic utility bladder compromised setting neoplastic, functional, or anatomic aberration, often indicated goal preserving kidney function survival. Procedurally, evolved considerably time simple ureters skin near functional restoration means using autologous intestinal segments. With proper counseling selection, these refinements enabled personalize their care selecting type likely result morbidity favorable quality life. Despite innovations, complications be substantial, ranging 56% within 30 days 90% days. Patients experience one more metabolic, psychological changes significantly impair discusses cystectomy, selection criteria, complications, outcomes, diversion. Bladder cancer, specifically urothelial origin, sixth diagnosed noncutaneous malignancy United States, estimated 81,400 new cases 17,980 deaths 2020 alone. At initial diagnosis, 20% 30% will present muscle invasive cancer (MIBC). Additionally, initially non-muscle disease progress MIBC despite bladder-preserving strategies. Without definitive therapy, carries poor prognosis, 5-year cancer-specific mortality rate 86%. Radical nonmetastatic MIBC, irrespective histologic variant. Given roughly 50% progression metastatic radical alone, particularly if surgery delayed than 12 weeks guidelines support administration cisplatin-based neoadjuvant chemotherapy, suggesting absolute 10-year overall survival 6% good pathological response. Although indications vary based on age comorbidities, this multimodal strategy resulted pelvic recurrence rates 4% without nodal metastases surgery. conditions not States. Currently, it exists merely last-resort modality severe lower symptoms do respond medical therapy. Guidelines issued American Urological Association endorse refractory non-neurogenic overactive fourth-line only. Data regarding sparse primarily limited single-institution series. Recent literature, however, suggests common indication neurogenic (multiple sclerosis, Parkinson’s disease, spinal cord injury, spina bifida) followed radiation cystitis, interstitial recurrent fistulous defects. Interestingly, majority there no evidence-based consensus whether perform concomitant appears risk residual pain carcinoma due retained must weighed against increased procedural morbidity. ?Brown ET, Osborn D, Mock S, et al. Perioperative conduit indications: population-based analysis. Neurourol Urodyn. 2017;36:1411-1416.?Brown Temporal trends Urology 2016;98:70-74. ?Essential Reading?Funt SA, Rosenberg JE. Systemic, perioperative muscle-invasive future horizons. Nat Rev Clin Oncol. 2017;14:221-234. Reading?Martini A, Sfakianos JP, Renstrom-Koskela L, natural history untreated cancer. BJU Int. 2020;125:270-275.?Osborn DJ, Dmochowski RR, Kaufman MR, Cystectomy disease: 2014;83:1433-1437.?Siegel RL, Miller KD, Jemal A. Cancer statistics, 2020. CA J Clin. 2020;70:7-30. No method currently exists, but advances 2 general categories: conduit, comprises (Box 1). Overall, large variation use techniques. Some higher-volume centers excellence report many whereas several datasets alternatively conduits. reasons behind undoubtedly multifactorial, considerations oncologic, life outcomes considered. Of note, presence rare variant squamous cell adenocarcinoma, appear influence choice diversion.Box 1Summary Types Diversion Notable Distinguishing FeaturesUrinary Conduit•Most diversion•Incontinent—requires urostomy appliance all times•Features abdominal wall stomaOrthotopic Neobladder•Higher complexity limits high-volume centers•Features reservoir•Voiding initiated ValsalvaContinent Cutaneous Diversion•Least diversion•Features necessitates ability self-catheterize stoma Orthotopic Valsalva Continent significant importance during preoperative planning thorough assessment baseline function. Most decline multiple factors believed play role, advancing age, comorbidities such diabetes hypertension, obstruction, nephrotoxic chemotherapeutic agents. segment used pouch bathed excreted patient’s accommodate reabsorption solutes paramount prevention life-threatening abnormalities. study 1,600 underwent either (76%) (24%) Eisenberg al demonstrated 73% cohort experienced glomerular filtration (eGFR) >10 mL/min/1.73 m2, did independently predict GFR decline. addition, strongest predictor decline, aside was eGFR. general, among other considered, > 40 m2 serum creatinine < 2.0 mg/dL deemed safe undergo Other discussed separately. ?Eisenberg MS, Thompson RH, Frank I, Long-term renal Urol. 2014;191:619-625.?Faraj KS, Mi Eversman effect Urol 2020;38(10):796.e15-796.e21. Reading Multiple segments However, ileal performed, accounting 33% 84% worldwide, contraindications diversions. described 1950 Eugene Bricker, widely adopted leading hallmark (as diversion) creation stoma, protrusion bowel through anterior allow excretion (Fig To construct isolated section well-vascularized intraoperatively, proximal end sewn into blind while distal protrudes wall. sutured small holes created lateral walls (ureteroenteric anastomosis) stoma. Up two-thirds require assistance urostomy. physical dexterity crucial compared reconstruction, patients’ adequately paramount. incidence reported up 74% cases. 1,000 were assessed median duration 15 years, onset chronic (CKD) 19% cohort, 15% developed urolithiasis. 10% strictures ureteroenteric anastomosis, well-known complication occurs 14% patients. precise etiology anastomotic stricture unclear, although blood flow ureter leakage periureteral fibrosis. some studies suggested ureteral stent placement across anastomosis may decrease leak, level 1 evidence does association between stenting rate. ?Shimko Tollefson MK, Umbreit EC, 2011;185:562-567. consists detubularized surgically modified anatomically functionally approximate 2). notion internal direct native urethra novel concept: pioneered 20th century. gained substantial popularity past decades, changing epidemiology influencing actual use. apparent benefits neobladder—obviating resulting improved void volitionally—the declining decade. trend entirely known, patient-specific advanced obesity, comorbidity role. given surgeon-specific individual case volume consolidation tertiary surely driving trend. voiding mechanism initiation maneuver, relaxation external urethral sphincter. light this, generally strives replicate 4 characteristics normal tract: adequate capacity (between 300 500 mL) filling pressures, antirefluxing prevent upper dilation, intact sphincter achieve maintenance unobstructed urethra. specific techniques construction beyond scope review, surgeons prefer ileum. Based Law Laplace (Pressure = Tension / Radius), intraluminal pressure inversely related radius spherical reservoir. urodynamic characteristics, folded shape maximize detubularization aids continence protection tracts inhibiting frequency amplitude peristaltic contractions. Patient Compared diversions, period self-catheterization postoperatively, thereby requiring mental competency facilitate sufficient training. chronological higher likelihood status, motivation avoid tolerate longer demanding Absolute include positive margin, (GFR mg/dL), inability self-intermittent catheterization neurologic hepatic insufficiency, strictures. important affect integrity inflammatory Contraindications•Positive margins•Chronic (serum 1.7-2.2 clearance 35-40 mL/min•Inability physical, neurological, impairment Relative Contraindications•Plan radiation•Chronic disease•Recurrent unique set challenges addressed immediate period. mucosa secrete >30 g mucus per day. Until mucosal epithelium begins atrophy lose secretory function, buildup subsequent retention. overdistention, prolonged catheterization. continue procedures. late dysfunction, infections, febrile infection similar techniques, asymptomatic bacteriuria high 78% neobladder; because around men women empty development Functional best optimized careful selection. provide maintain volitional voiding. As such, motivated willing adhere strict rehabilitation pathway. addition rigid timed-voiding schedule gradually increase compliance, emerging supported floor therapy incontinence. dysfunction population vary, pooled observations daytime improves 6 months postoperatively. 200 nighttime 10 92% 70%, respectively. 23% outlet prolapse stricture. managed endourologically, findings stress self-catheterize. ?Pietzak EJ, Donahue TF, Bochner BH. Male neobladder. North Am. 2018;45:37-48. Richard Gilchrist 1950s alongside Bricker’s conduit. prowess largely abandoned until interest renewed 1980s. adoption performed. option desire capable intermittent self-catheterization, otherwise qualify whose cannot incorporated pre-existing disease. While number Similar uses create internalized low-pressure urine. fashioned contrast aforementioned ectopically placed catheterizable bulky appliance. Numerous variations exist performing review. Indiana pouch, 3). Briefly, involving entire right hemicolon terminal ileum supply. colonic passed configuration, functions channel, ileocecal valve provides mechanism. subject immediately overdistention excess plugging, close monitoring output frequent catheter irrigation. authors’ institution, interval irrigation day continued confirmed fluoroscopic pouchogram later. Short-term shown occur 209 neobladder, 72%, 88%, 76% respectively, least 90 infections also inherent complications—including strictures—appears reconstruction. noted stomal stenosis 41 months, revision. ?Nazmy M, Yuh B, Kawachi Early robot-assisted cystectomy: standardized analysis type. 2014;191:681-687. Case: 69-year-old man found microscopic hematuria routine urinalysis. After referral urology, cystoscopic evaluation his revealed 3-cm posterior mass. Pathology staging ultimately notable carcinoma. He 3-month course chemotherapy he tolerated well, moderate bone marrow suppression paresthesias. Upon completion, regional lymphadenopathy, doing following regularly oncology surveillance.Several later, eventually referred clinic progressively worsening acidemia. denies any nonsteroidal anti-inflammatory medications. Laboratory values following: creatinine, 1.4 (preoperative 0.9mg/dL, corresponding MDRD Study equation 83mL/min/1.73m2); sodium, 142 mEq/L; chloride, 112 bicarbonate, 19mmol/L; urea nitrogen, 32mg/dL; potassium, 5.4 magnesium, 1.6mg/dL; calcium, 8.6 mg/dL; albumin, 3.8 g/dL. liver tests, aminotransferase levels, reference range.Question 1: scenario, what is/are possible etiologies hyperkalemia?a)Decreased functionb)Reduced ammonium excretionc)Reduced bicarbonate lossd)Pancreatic lossese)Cisplatin toxicity hyperkalemic acidemiaQuestion 2: Which statements scenario true?a)Measurement electrolytes calculation anion gap reliable diagnosis hyperchloremic acidemia.b)Administration nicotinic acid chlorpromazine regimen.c)Citrate bicarbonate-based buffer supplementation treat acidemia hyperkalemia diversion.d)This gastric segment.For answers questions, see text. surveillance. Several range. Question segment. For fundamental