Urology 5th year, 2nd lecture/part two (extended/detailed version) (Dr. Ali Kamal)
Definition • A primary bladder stone is one that develops in sterile urine; it often originates in a kidney and passes down the ureter to the bladder, where it enlarges. • A secondary bladder stone occurs in the presence of infection, bladder outflow obstruction, impaired bladder emptying or a foreign body such as nonabsorbable sutures, metal staples or catheter fragments. Composition and cystoscopic appearance• Oxalate calculus is a primary calculus that grows slowly. Usually, it is of moderate size and is solitary. Its surface is uneven (mulberry type); sometimes it bristles with spines .Although calcium oxalate is white; the stone is usually dark brown or black because of the incorporation of blood pigment on to it.• Uric acid and urate calculi are round or oval, fairly smooth, and vary in color from pale yellow to light brown: they may be single or multiple. They may occur in patients with gout, but are also found in patients with ileostomies or with bladder outflow obstruction.• Cystine calculus occurs only in the presence of cystinuria and is radio-opaque owing to its high sulphur content.• Triple phosphate calculus is composed of ammonium, magnesium and calcium phosphates, and occurs in urine infected with urea-splitting organisms. It tends to grow rapidly. In some instances, it occurs on a nucleus of one of the foregoing types of calculus; much more rarely on a foreign body. In others, the nucleus is composed of desquamated epithelium and bacteria. It is dirty white in color and of chalky consistency. A bladder stone is usually free to move in the bladder. It gravitates to the lowest part of the bladder which is the outflow when the patient is erect or sitting. In the recumbent position (and at cystoscopy) the stone occupies a position behind the interureteric ridge.. Clinical features Males are eight times more often affected than females Symptoms • It may be asymptomatic • Frequency is the earliest symptom.
• There may be a sensation of incomplete bladder emptying. • Pain (Strangury) is most often found in patients with a spiculated oxalate calculus. It usually occurs at the end of micturition and is referred to the tip of the penis or to the labia majora, more rarely to the perineum or suprapubic region. • Haematuria • Interruption of the urinary stream is due to the stone blocking the internal meatus and may develop into acute retention of urine • Symptoms of urinary infectionExamination • Rectal or vaginal examination is usually normal; occasionally a large calculus is palpable in the female. • Examination of the urine usually reveals microscopic haematuria, pus or crystals typical of the calculus. • Radiography — in most patients, the stone is visible on a plain X-ray .If the stone is radiolucent, a filling defect may be visualised on IVU. • Cystoscopy is essential and most stones nowadays can be dealt with endoscopically.TreatmentLitholapaxyThe blind litho trite is a satisfactory instrument for the treatment of a large, hard stone. Otherdevices include the stone punch which is useful to crush small fragments further so that theycan be evacuated with an Ellik evacuator.Contraindications to per urethral litholopaxy • •Urethral: o A urethral stricture that cannot be dilated sufficiently o When the patient is below 10 years of age • •Bladder:A contracted bladder • •Stone characteristics:A very large stone
Technique; the patient should receive appropriate antibiotics treatment before operation.The major advantage of the blind lithotrite is that, because of its solidity and strength, harderstones can be crushed than is the case with the optical instrument. A cystoscopic lithotrite,stone punch or stone loop enables the stone or stone fragments to be seized under vision. Tocarry out litholapaxy, the bladder is filled with about 200—300 ml of saline and the instrumentis introduced with its obturator in place so that its closed jaws point downwards. Afterirrigation of the bladder and insertion of the telescope, the stone is seen. The distal blade ishooked over the centre of the stone and grasped. After withdrawing the telescope slightly toprevent damage to the optics, the screw is turned slowly, breaking the stone. Large fragmentsare crushed into small ones by repeating the manoeuvre. With the jaws closed the lithotrite isrotated so that the jaws point upwards, and after removing the telescope and allowing thesaline and stone fragments to escape, the instrument is withdrawn. The use of an Ellikevacuator is necessary to ensure complete removal of all stone fragments.Mechanohydraulic lithotripsyThe lithoclast generates energy by purely mechanical means using a steel ball which is fired ina closed chamber at the proximal end of the endoscopic probe. Also, an energy source isgenerated between paired or concentric electrodes. With repeated discharges, the stone isbroken into small pieces. The probes come in two or three sizes and it is sensible to use thelargest (9 F) for bladder calculi. The patient is cystoscoped and the probe placed close to thestone, but away from the end of the telescope, and fired.Evacuation of the fragments; Fluid (200 ml) is introduced into the bladder. The evacuator, filledwith solution, is fitted on to the sheath. The bulb is compressed slowly and then permitted toexpand. The returning solution carries with it fragments of stone which sink into the glassreceptacle. Alternate compression of the bulb and aspiration is continued until no furtherfragments -fall. The beak of the cannula is turned to the left and to the right, and suction isapplied in these situations. After checking that no fragments are left in the bladder, a Foleycatheter is introduced and left in Situ for 24 hours.Suprapubic lithotomyPercutaneous suprapubic litholapaxyExtracorporeal shock wave lithotripsy (ESWL) Removal of a retained Foley catheterThis is not an uncommon problem and is usually caused by the channel which connects theballoon to the side arm becoming blocked, usually at the very distant end. The best way ofdealing with this problem is to further inflate the balloon with 20 ml of water and then burst the
balloon percutaneously using a spinal needle under ultrasound screening. The instillation offluid such as ether to dissolve the balloon is not recommended because fragments of balloonmay be left behind. However the balloon is burst, it is important to subsequently cystoscopethe patient to ensure that any fragments are removed before they can form a foreign bodycalculus. Foreign bodies in the bladderThe commonest foreign body is a fragment of catheter balloonComplications of a foreign body in the bladder i. Lower urinary tract infection ii. Perforation of the bladder wall iii. Bladder stoneTreatmentA small foreign body can usually be removed per urethram by means of an operatingcystoscope. Occasionally, a suprapubic approach using the Percutaneous insertion of acystoscope is needed. Diverticulum of the bladderThe normal intravesical pressure during voiding is about 35—50 cmH2O. Pressures as greatas 150 cmH2O may be reached by a hypertrophied bladder endeavouring to force urine pastan obstruction. This pressure causes the mucous lining between the inner layer ofhypertrophied muscle bundles to protrude, so forming multiple saccules. If one or more, butusually one, saccule is forced through the whole thickness of the bladder wall, it becomes adiverticulum. Congenital diverticula are due to developmental defect.Etiology of diverticulum• Congenital diverticulum — This is rare. It may be situated in the mid line anterosuperiorly and represent the unobliterated vesical end of the urachus. It empties with the bladder and is symptomless. Others in the usual situation on the base of the
bladder can occur without obstruction, and may require excision because of the risk of chronic infection or stone formation in a young adult• Pulsion diverticulum — the usual causative obstructive lesion is bladder outflow obstructionComplications 1. Recurrent urinary infection; Squamous cell metaplasia and leucoplakia are infrequent complications. 2. Bladder stone 3. Hydronephrosis and hydroureter 4. NeoplasmClinical featuresAn uninfected diverticulum of the bladder usually causes no symptoms. The patient is nearlyalways male (95 per cent) and over 50 years of age.There are no pathognomonic symptoms; they are those of lower urinary tract obstruction,recurrent urinary infection and pyelonephritis. Haematuria (due to infection, stone or tumour)is a symptom in about 30 per cent.Diagnosis; 1. Cystoscopy 2. Intravenous urography 3. Retrograde cystography 4. UltrasonographyIndications for operationOperation is only necessary for the treatment of complicationsPreoperative treatmentWhen the urine is infected, suitable preoperative antibiotic treatment is given. In the presenceof gross sepsis and retention of urine, it is necessary to resort to an indwelling urethralcatheter for a period.
Combined intravesical and extravesical diverticulectomyThis is the standard operation. Cystoscopy is performed, a ureteric stent is passed up theureter on the affected side.The anterior bladder wall is exposed through a suprapubicincision, the peritoneum is displaced upwards and the side of the bladder bearing thediverticulum is cleared from surrounding structures until the pouch is identified. The bladder isthen incised in the mid-line and the diverticulum is packed with a strip of gauze. Usually theneck of the diverticulum can be separated from the ureter and when the pouch is free it issevered from its attachment to the bladder with a diathermy knife. The resulting defect isclosed in two layers. A suprapubic catheter is left in place and an extravesical drain isinserted.Traction diverticulum (syn. hernia of the bladder)A portion of the bladder protruding through the inguinal or femoral hernial orifice occurs in 1.5per cent of such herniae treated by operation. Urinary fistulae • Congenital urinary fistula Ectopia vesicae; from a patent in association with imperforate anus • Traumatic urinary fistulaVesicovaginal fistulaEtiology • Obstetrics — the usual cause is protracted or neglected labour; • Gynaecological — the operations chiefly causing this complication are total hysterectomy and anterior colporrhaphy; • Radiotherapy • Direct neoplastic infiltration.
Clinical featuresThere is leakage of urine from the vagina and as a consequence excoriation of the vulvaoccurs. Digital examination of the vagina may reveal a localised thickening on its anteriorwall, or in the vault in the case of posthysterectomy fistula. On inserting a vaginal speculum,urine will be seen escaping from an opening in the anterior vaginal wall.Differential diagnosis between a ureterovaginal and vesicovaginal fistula can be made if aswab is placed in the vagina and a solution of methylene blue is injected through the urethra;the vaginal swab becomes coloured blue if a vesico-vaginal fistula is present. With the adventof good, portable X-ray image intensifiers, a cystoscopy and bilateral retrograde ureterogramsprovide a more reliable demonstration of the anatomy. An IVU should be performed toexclude a coincidental ureterovaginal fistula.Treatment Just occasionally, conservative management of a vesicovaginal fistula followinghysterectomy by urethral bladder drainage is successful. Usually, operative treatment isrequired. The low fistula (subtrigonal) is best repaired per vaginam. The fistula is exposedwith dissection of the edges which are freshened. The bladder is then closed usingabsorbable sutures and the vagina subsequently closed with a separate layer. A urethralcatheter should be left in situ for at least 10 days. For the higher (supratrigonal) fistula, atransvaginal approach can be extremely difficult. These patients should always becystoscoped prior to a repair procedure and bilateral ureterograms performed as occasionallyone of the ureters is also involved. For the high fistula, a suprapubic approach is the bestmethod in most hands. The Pfannenstiel incision should be re opened, the bladder should bedissected free from the peritoneum and bisected posteriorly in the midline down to the level ofthe fistula. The bladder is then separated from the vagina and, occasionally, carefuldissection from the rectum is also required. The vagina is then closed with a heavy catgutsuture and omentum brought down to lie between the closed vagina and the bladderanteriorly. This is lightly sutured in place and the bladder then closed. A urethral andsuprapubic catheter should be left in situ for 10—14 days.For the patient with a ureterovaginal fistula, an extraperitoneal approach to the ureter via theprevious Pfannenstiel incision is made.Fistula from renal pelvis to skin or gutTuberculosis of a kidney may result in caseation and a chronic sinus leading to duodenum,colon or skin in the iliac fossa or lumbar triangle. Similarly, a pyonephrosis mayspontaneously discharge into the gut or on to the skin. Cases of duodenal ulcer involving the
pelvis of the right kidney and Crohn’s disease involving either renal pelvis or ureter, or casesof xanthogranulomatous pyelonephritis may cause fistulae.Fistulae arising as a result of infectionThe commonest cause is diverticulitis of the colon. They may also follow Crohn’s disease,appendix abscess or pelvis sepsis in association with acute salpingitis, or may be the result ofsurgery and radiotherapy within the pelvis.Cases due to carcinomaBy the time a fistula between the bowel and the bladder has developed the tumour is usuallylocally advanced, but may be operable.Urethral fistulaeThese occur as the result of infection above a stricture producing a para urethral abscesswhich ruptures into the urethra, allowing extravasation to occur suddenly into the scrotum andperineum. Urine and infection extend into the upper 2.5 cm of thigh and lower abdominal wall.Widespread cellulitis and tissue necrosis (which may lead to Fournier’s gangrene) may occurunless drainage of urine is achieved by suprapubic cystostomy, and the tissue planes arefreely drained by inguinal and scrotal incisions.Neoplastic fistulaePrimary bladder tumours very rarely fungate through the abdominal wall unless an opencystotomy has been performed without further treatment, such as low dose irradiation beingperformed to cut down the risk of wound implantation.. Involvement of the bladder by tumoursof cervix, uterus, colon and rectum can produce fistulae, as may lymphosarcoma of the smallgut. Carcinoma of the prostate rarely produces a rectal fistula. Treatment is palliative .