3Hippocrates :who described the symptoms of renal colic. Historical overview :Hippocrates :who described the symptoms of renal colic.In 1889 ,Gustav performed the first successful stone manipulation.In 1973, the first two modalities were described ureteroscopically: ultrasonic lithotripsy by Goodfriend1 and electrohydraulic lithotripsy by Reuter et a
4Factors affect the management of renal stones Stone factorssizenumberCompositionRenal anatomyobstruction/stasishydroUPJOcalyceal diverticulumhorseshoe / other ectopic/fusion anomalieslower pole
6The indications for treatment of an :asymptomatic calyceal stone pediatric patientsolitary kidneyhigh risk profession (pilots)women considering pregnancyAsymptomatic stones >4mm most likely will fail observation.
7approach to treatment of a stone according to stone size stones < 10mm: 50-60% of all stonesESWLfirst-line, regardless of composition or location: stone-free rate 80%PCNL, ureteroscopyonly if special circumstance: ESWL failure, anatomic obstruction more invasive
8approach to treatment of a stone according to stone size stones 10-20mmESWL first line: stone-free rate 65%poor result if cysteine, lower polePCNL, ureteroscopy: stone-free rates 89% and 72% use if stone composition, location, or renal anatomy prevent ESWL.stones 20-30mmPCNL first line, followed by ESWL if neededESWL: stone-free rate 34%, high rates (33%) of 2nd procedure if used alone.ureteroscopy inferior to PCNL if large stone burden: 1/3 require 2nd look, high incidence of recurrences.stones > 30mmPCNL first line regardless of size, location, compositionESWL stone-free rate only 27%.
10Ureteral Stones Proximal Ureteral Stones Distal Ureteral Stones ESWL with or without stone manipulation; ureteroscopy; PNL; and, rarely, open and laparoscopic stone surgery.Distal Ureteral StonesESWL with or without a stent; ureteroscopy with extraction or intracorporeal lithotripsy; and, rarely, open and laparoscopic stone surgery .
11Conservative treatment Ureteric stone have high probability of spontaneous clearance.According to a meta-analysis by AUA Guidelines Panel, newly diagnosed stones with diameter < 5 mm will pass up to 98%.Passage depends on degree of obstruction, urothelial edema, and degree of impactionOverall passage rate 25% for proximal, 45% for mid and 75 % for distal ureteric stonesMedical managementCa antagonist + steroidHigher Expulsion rate in double blind study 79% vs 35%.Tamsulosin80% vs 62%
12Proximal Ureteral Stones ESWL should be the primary approach for stones < 1 cm in the proximal ureter.For stones larger than 1 cm in diameter, ESWL, PNL, and ureteroscopy are all acceptable choices .A review of the literature shows excellent results for ureteroscopy lithotripsy using the holmium laser for proximal as well as distal ureteral calculi, with a mean stone-free rate of 95% associated with a low perforation and stricture rate of about 1% .
13Distal Ureteral Stones Areview of retrospective series after 1997shows that URS was optimal choice over ESWL because of superior stone free rate(85% for stone<5mm and 95% for stone >5mm with ESWL and 100% treated with URS regardless of stone size.
14The indications for intervention for ureteral stones intractable sxinfectionPatients who fail ESWL.Patients with a history of cystine stones.Patients with distal obstruction.Patients with impacted stones.Obese patients.Patients with bleeding diathesis.When ESWL is not readily available.Stone unlikely to pass spontaneously
16The AUA Ureteral Stone Guidelines Panel meta- analysis showed ESWL to have: Stone clearance of 74% for stones < 1cmStone clearance of 46% for stones 1-2 cmMore than 1 session of is often requiredSuccess rate decreases after subsequent re treatmentsPace et al. in a series of over 1500 pts treated with Dornier MFL 5000 lithotripser, showed:Superior success rate for upper/ mid ureteric calculi comparing to lower calculiInitial stone free rate of 68% decreased to 46% on 1st re treatment and 31% on 2nd re treatment
17The AUA Update series (2006) concluded that Uretroscopy is highly efficient and minimally invasive for all proximal, mid & distal stones.The article focused that the 1st line treatment for managing ureteral stones should not only depend on stone free rateAdditional variables include efficiency, invasiveness, symptoms, pt satisfaction and morbidity
28Localization systemsImaging is employed to localize the stone and direct the shockwaves onto the calculus.The 2 methods commonly used to localize stones are fluoroscopy and ultrasonography.Real-time imaging without interrupting the treatment can be obtained with in-line fluoroscopy, which also allows continuous adjustments during a treatment session to pinpoint shockwave placement onto the stone.
29Localization systemsUltrasound localization allows the visualization of both radiopaque and radiolucent renal stones in the absence of fluoroscopy (without intravenous contrast administration)Most second-generation lithotriptors can employ this imaging modality, whose costs are much lower than radiographic systems.Although ultrasonography has the advantage of avoiding exposure to ionizing radiation, ureteral calculi are frequently very difficult to localize with sonography alone because of interposed air-filled intestinal loops. Smaller stones may be particularly hard to identify with ultrasonography.In addition, urologists are often more familiar with fluoroscopic localization.
30Localization systems Advantages of fluoroscopy include: identification of both renal and ureteral calculi .Tracking of migrating fragments in the ureter. Fluoroscopy, however, employs ionizing radiation and fails to visualize radiolucent or minimally radiopaque stones unless contrast is administered.The administration of intravenous iodine-based contrast during treatment can be useful in localizing these stones with fluoroscopy.Alternative methods of stone visualization include the insertion of a ureteral catheter before the procedure and the direct injection of contrast into the collecting system retrograde ureteropyelography.
31Coupling mechanismsA coupling system is needed to transmit the energy that is created by the shockwave generator across the skin surface, through visceral tissues, and ultimately to the stone itself.Traditionally, this has been accomplished by placing the patient in a large (1000 L) water bath (e.g., with the first- generation device, the Dornier HM3 lithotriptor).The second- and third-generation lithotriptors, however, small water-filled drums or cushions with a silicone membrane are used instead of large water baths to provide air-free contact with the patient's skin.
32Mechanisms of Stone :Comminution Four potential mechanisms for ESWL stone breakage have been described:(1) compression fracture.(2) spallation.(3) acoustic cavitation.(4) dynamic fatigue.
34Contraindications: Absolute contraindications to ESWL include:Acute urinary tract infection.Uncorrected bleeding disorders.Pregnancy.Sepsis.Uncorrected obstruction distal to the stone.
35Relative contraindications include the following: Altered mental status.Body weight greater than 300 lb.Orthopedic or spinal deformities, renal ectopy, or renal malformations (including horseshoe and pelvic kidneys)
36Poorly controlled hypertension Preexisting Pulmonary and cardiac problems.Before ESWL, oral anticoagulants, such as clopidogrel (Plavix) and warfarin (Coumadin) must be discontinued to allow normal clotting factors to resume.
37Stenting and extracorporeal shockwave lithotripsy The cystoscopic placement of a ureteral stent ensures upper urinary tract drainage.Prevents transient obstruction from fragment migration after ESWL.Helps localize ureteral calculi.Employed to push back a stone from the ureter into the kidney, where treatment may be easier and more successful.
38The traditional general indications for ureteral stenting before ESWL include : (1) large, dense stone burdens (>10-15 mm).(2) completely obstructing stones, impacted stones, or both.(3) poorly visualized stones, where the stent is required to aid in localization.
39Renal complicationsPerinephric, Subcapsular,intranephric hematoma may be associated with severe pain.Unexplained or unusually severe pain,significant bleeding, or any unusual drop in blood pressure may suggest a hematoma.Hemorrhagic complications after ESWL rarely necessitate transfusion, embolization, or nephrectomy, although any of these are possible.
40Hematuria occurs in the majority of patients and clears within the first few postoperative days. Passage of many clots and urinary clot retention occur infrequently.Post-ESWL sepsis is infrequent if the preoperative urine is sterile.
41Hypertension is an unusual complication of ESWL, but it may occur as a sequela of a large perinephric hematoma.Older patients with abnormal renal perfusion may develop hypertension within 26 months after the ESWL session.Patients who receive ESWL at higher risk to develope hypertension and diabetes than patients who underwent other therapies for stone removal.
42Steinstrasse:2% to 10 % post ESWL Patients with asymptomatic and nonobstructing steinstrasse are monitored closely with serial imaging.Asymptomatic or mild symptomatic steinstrasse with mild dilation of the upper urinary tract can be managed conservatively with antibiotics and analgesics as needed.If fragments are not passed after 3-4 weeks, ESWL or endoscopic lithotripsy may be repeated.
43steinstrasseObstructing, infected, or symptomatic steinstrasse requires either percutaneous nephrostomy drainage or ureteroscopic treatments with stenting to ensure drainage.
44The RF for developing acute renal side effects after ESWL age: children and elderlyobesitycoagulopathiesthrombocytopeniaDMCHFhypertensionincreased thromboplastin timeuse of ASA
45The acute and chronic histologic changes seen in kidneys after ESWL venous thrombimild tubular necrosistubular dilation and cast formationdamaged veins and small arteriesrupture of glomerular and peritubular capillariesChronicnephron lossdilated veinsstreaky fibrosisdiffuse interstitial fibrosisCa and hemosiderin deposits
46Factors increase the degree of renal trauma in animals Number of shocksPeriod of shock wave administrationAccelerating voltage (higher voltage increases damage)Type of shock-wave generatorKidney sizePreexisting renal impairment
47Intracorporeal lithotriptors: How does EHL work?fragments stones w/ shock waves generated by an underwater electrical dischargeunderwater spark plug w/ 2 concentric electrodes of different voltage polarities separated by insulationcurrent supplied to overcome insulative gap spark producedspark discharge causes explosive formation of a plasma channel and vaporization of the water surrounding the electrode
48EHLrapidly expanding plasma causes hydraulic shock wave, then cavitation bubble formationdepending upon the proximity of the probe to the stone surface, the collapse of the cavitation bubble may be symmetrical (~1mm from stone), resulting in a strong secondary shockwave or asymmetrical (~3 mm), leading to the formation of high-speed microjetsshock wave not focused (unlike ESWL), therefore, the stone must be placed where the shockwave is generatedmay use saline irrigation
49What are the advantages and disadvantages of EHL? narrow margin of safety due to risk of ureteral perforation expansion of cavitation bubblehigh risk of perf w/ impacted stonesretrograde propulsion of stoneslarge number of fragments produced.Advantages:cheapest intracorporeal devicesuccessful in 90% rough stones break easilyflexibility of probes
50laser = light amplification by stimulated emission of radiation. Lasers have become a trusted weapon in the urologists' arsenal in treating stone disease.The holmium:YAG laser has revolutionized intracorporeal lithotripsy:wavelength of 2100 nm with a pulse duration of ms.The optical laser fibers available for use with the holmium: YAG lasersare composed of flexible low-OH silica and available in diameter sizes ranging from 200,365,550 and 100mm.The 365mm fiber is most often employed for the majority of lithotripsy procedures .
51How does laser lithotripsy work? The subsequent plasma formation, cavitations effects and pressure waves are weak, allowing for a photo thermal ablation of calculi.Initial transmission of the holmium laser beam through water vaporizes a channel.This vapor channel become a more efficient conduit for transmitting the energy beam into the stone, called the "Moses" effect.perpendicular contact with the stone surface.most ureteral lithotripsy is accomplished at pulse energies of 600 to lOOOmJ at 6 to 10 Hz.Ca , struvite calculi have been shown to degradefibers most, while uric acid and cystine calculi cause the least degradation.
52What are the advantages and disadvantages of laser lithotripsy? safer and more efficient.ability to fragment all stones.smaller stone debris easily irrigated.decreased chance of retropulsion.reusable fibers.Disadvantages:high initial costproduction of cyanide when uric acid stones treated not significant.
53What is ballistic lithotripsy? jackhammer" lithotripsy: metal projectile in the handpiece of the lithoclast is propelled by measured bursts of compressed air against the head of a metal probe at 12 Hz.What are the advantages and disadvantages of ballistic lithotripsy?wide margin of safetylow risk of ureteral perforationno heat is producedsuccess rate similar to EHL73-96%stones easily pinned downno disposable costs, long life of probeslow cost, low maintenanceDisadvantage:Rigidhigh rate of retropulsionsignificant power loss w/ bowing of probe.
54How does ultrasonic lithotripsy work? application of electrical energy to excite a piezoceramic plate in ultrasound transducerplate resonates at a specific frequency and generates ultrasonic waves at 23-25kHztransformed into longitudinal and transverse vibrations of the hollow steel probe, transmitting energy to the stonecauses stone to resonate at high frequency and break
55What are the advantages and disadvantages of US lithotripsy? stones removed continuously w/ suctionminimal damage to tissues, minimal heat creation.Disadvantage:rigid probe, small diameter difficult to rx ureteral stone.
56How does ultrasonic lithotripsy work? application of electrical energy to excite a piezoceramic plate in ultrasound transducerplate resonates at a specific frequency and generates ultrasonic waves at 23-25kHztransformed into longitudinal and transverse vibrations of the hollow steel probe, transmitting energy to the stonecauses stone to resonate at high frequency and break
57:UreteroscopyAlmost all ureteric stones can be treated by ureteroscopiesTechnology now offers small caliber scopes with good optical quality in rigid, semi rigid and flexible deflectable forms making accsess to mid/prox ureter safePneumatic, ultrasonic, electro-hydraulic, and laser lithotriptersIntroduction of the Ho:YAG thermal laser made all stone types can be treated
58STEP-BY-STEP URETEROSCOPY IN THE TREATMENT OF URETERONEPHROLITHIASIS: Preparation of the patient.Antibiotic Prophylaxis.EUAPositioning of the Patient:dorsal lithotomy position .proximal ureter or kidney:slight Trendelenburg .Cystoscopy.Safety Guide Wire: a general principle of ureteroscopy is always to have a safety guide wire present intraoperatively.
59If the wire cannot traverse past an obstructing stone: Insert a 5 Fr ureteral catheter over the guide wire to buttress the guide wire and provide backing to propel the guide wire past the stone.Exchange the PTFE guide wire for an angled hydrophilic wire or combination wire with an angled hydrophilic tip and attempt to maneuver past the stone.Exchange the 5 Fr ureteral catheter for an angled ureteral catheter or vascular catheter) in combination with the angled hydrophilic wire to manipulate past the obstructing stone.
60ureteroscope specifications include the following: Tip diameter F (6.9F most common)Optics - Fiberoptic bundlesWorking channels - One, 2, or 3 (2- channel preferred)Accessory length - Average 40 cm
61Ureteroscope (semirigid) more:Advantage durable, larger working channel for larger instruments (e.g., laser fibers, baskets), better visibility related to Abilitys increased irrigatingDisadvantages: may be more traumatic to the urethra/ureter, limited access within the ureterTypically for stones below the iliac vesselsUreteroscope (semirigid)Can reach every part of the urinary tract (including lower poleSome models have "double deflection" allowing easier access to all calycese kidneyDisadvantages: flexible fiberoptics require frequent repairs, which are costly; smaller working channels have lower flow rates; the image is not as sharp as with semirigid endoscopes because of the smaller fiberoptic bundlesy)Typically used for stones above the iliac vessels and in the kidneyUreteroscope (flexible)
62ureteroscope Energy sources include the following: Holmium:YAG (ie, yttrium-aluminum- garnet) laserNeodymium:YAG laserElectrocautery .Electrohydraulic lithotripsy.Mechanical impactor (ie, Lithoclast).
63 INDICATIONSDiagnostic indications for ureteropyeloscopy are as follows:Abnormal imaging findings - Filling defectObstruction - Determination of etiologyUnilateral essential hematuriaLocalizing source of positive urinary cytology results, culture results, or other test results
64INDICATIONSTherapeutic indications for ureteropyeloscopy are as follows:Endoscopic lithotripsyRetrograde endopyelotomyIncision of ureteral stricturesImprovement of calyceal drainageTreatment of calyceal diverticular lesionsTreatment of malignant urothelial tumorsTreatment of benign tumors and bleeding lesions
65Contraindications: Untreated urinary tract infection. endoscopy without appropriate antibiotic coverage is a relative contraindication.Uncorrected bleeding diathesis is also a relative contraindication.
66Work up Lab Studies: Coagulation factors Urinalysis for urine culture Prothrombin timeActivated partial thromboplastin timePlatelet countUrinalysis for urine cultureStandard preoperative laboratory workupCBC countElectrolyte levelsSerum creatinine and BUN determination
67Work up Imaging Studies: Useful preoperative imaging studies depending on the clinical presentation include the following:Renal sonographyIVPCT scanMRI
68COMPLICATIONSMinor intraoperative complications Minor ureteroscopic complications are those that have no long-term deleterious effects and, if treated promptly, cause only minimal or transient postoperative problemsColic/painFeverFalse passageHematuria
69The minor complication rate from ureteropyeloscopy was decreased based on: Refined technique.Experience of the operators. problems.Prophylactic parenteral antibiotics.Careful guidewire placement.Minimization of excessive ureteral dilation.Postoperative ureteral stenting .all impacted on the rate of postoperative problems. This, combined with better surgical training and improved instrumentation, resulted in this very positive trend .
70Major complications Perforation (highest incidence w\EHL) Treatment of ureteral perforation consists of immediate termination of the procedure, ureteral stenting for 2 to 4 weeks, and careful follow-up to ensure that strictures do not form.
71Stricture due to ureteral trauma or from stone impaction, iatrogenic injury or retained stone fragments in the ureteral wall after treatment.Prolonged stenting (4 to 6 weeks) may prevent ureteral strictures if significant ureteral trauma has occurred during ureteroscopy.If strictures do form, incision (with cold knife, cautery, or laser) and stenting may be successfulBalloon dilation with subsequent stenting is another option.Open repair with excision of the strictured segment may be necessary if endoscopic measures fail.
72Lost stone no further treatment Urinoma Submucosal stones Ureteral avulsion (the most severe ureteral complication)If the continuity of the ureter can be re-established by a guide wire already in place, a trial of stenting for several months while the ureter heals may be attempted, but a stricture of the ureter often results.if the ureteral injury is severe, immediate open reconstruction of the ureter is required .Lost stone no further treatmentUrinomaSubmucosal stones
74Postoperative details: At the completion of a ureteroscopy, internal ureteral stents commonly are placed to help facilitate healing and ensure drainage, particularly if vigorous therapeutic maneuvers were performed.Fortunately, there is a growing evidence in the form of randomized prospective clinical trials suggesting that routine stenting for uncomplicated URS may be unnecessary
75Postoperative details: Internal ureteral stents are associated with LUTS and transient hematuria .Removal of ureteral stents is performed, depending on the complexity of the treatment.Stents are removed most commonly in the office .
76Percutaneous Endourology INDICATIONSDiagnostic indicationsAntegrade pyelography .Pressure/perfusion study (Whitaker test).Therapeutic indicationsNephrostomy catheter drainage.Antegrade ureteral stenting.Treatment of ureteral strictures .Percutaneous endopyelotomy.Percutaneous nephrostolithotomy.Perfusion chemolysis to dissolve and clear certain renal stones .Endoscopic resection and treatment of upper urinary tract urothelial tumors .
77PCNL:1970 Induction for PCNL: Staghorn calculi : AUA guidelines recommend PCNL as first line .Large renal stone burden ,more 3cm carries more a success rate around 100%.Large lower pole renal calculi .Cystine stone .Abnormalities of renal and upper tract anatomy .(e.UPJ obstruction ,caliceal diverticula ,malformed kidneys (horseshoe and pelvic ).ESWL and ureteroscopy failures.Nephrolithiasis in transplanted kidney .
78Preoperative preparation: Complete history and physical examination.Urine sterility is mandatory for all elective procedures .(clean-contaminated).Anesthesia ,PNL can be performed after the administration of general ,epidural or local.Opacification of collecting system. A ureteral catheter serves several purposes:A-to opacify and to distend the collecting system b-to provide an optimal target for percutaneous puncture.
796-Positioning of the Patient: Figure Position of the patient for PNL. A, Side to be treated is elevated approximately 30 degrees. The "down" arm should be placed at the patient's side. B, All pressure points are carefully padded. C, The "up" arm should be placed in an abducted position. The patient is placed far enough down the table so that the center post of the table does not impede movement of the C-arm.
80The factors to be considered when choosing renal access for PCNL Puncture through the upper pole infundibulum is the most dangerous because the posterior segmental artery crosses the posterior surface of the infundibulum in 57% of cases.Direct puncture into the renal pelvis injured large retropelvic vessels in one third of cases.Therefore , the preferred point of entry into the collecting system is along the axis of the calyx, through the papilla.
81The factors to be considered when choosing renal access for PCNL Approach below 12th rib if possible to avoid pleural injurysupracostal puncture performed only during full expirationPuncture too laterally may injure colon.Lower pole puncture associated with fewer complicationsSolitary calyceal stone: preferred approach directly into calyx with stone.
82Contained:A rigid nephroscope that is aligned with the infundibular access allows optimal visualization of the stone and easier access into the renal pelvis.The risk of renal trauma is reduced, as there should be little need to place significant torque on the rigid instruments.stones in anterior calyces may be difficult to access in this manner; a direct puncture into the calyx is often at an acute angle with the collecting system, making access into the renal pelvis difficult not only with a rigid instrument but also with a flexible endoscope.
83The indications for a supracostal :puncture predominant amount of stone in upper calyces.associated UPJO requiring endopyelotomy.multiple lower pole infundibula and calyces with stones.ureteral stonestaghorn with substantial upper pole stone burden.horseshoe kidneys.
84The indications for multiple :punctures for PCNL any calyx contains stones larger than 2cm and unreachable through primary access point with rigid instrument .stones < 2cm, cannot be reached with flexible instrument.Y puncture: stone in adjoining calyx cannot be reached w/ flexible nephroscope.used for stones < 2cm, 6.9F semi-rigid ureteroscope
85The possible ways to gain perc access Hawkins-Hunter systemLawson systemretrograde approachCT/MRI approachUS approachfluoroscopic anterograde approach
86The technique of percutaneous nephrostomy choose tractposterior calyx, as major vascular structures are avoidedlook with C-arm at 90 degrees, then 30 degrees away and towardsoverlying skin site marked w/ snap18G angio needle advanced in plane of fluoro beam with C-arm 30 degrees toward surgeonlook for "bull's eye sign“.advance in 1-2mm increments.depth monitored by rotating back to vertical positionif seems to be in a calyx, remove stylet , look for urineadvance stiff guide wire across UPJ.dilate to 30F.
88Intercostal Approach: The risk of hydrothorax and hemothorax is increased when percutaneous access to the calyces is performed above the 12th rib.Several endourologic techniques to access the superior calyces while minimizing complications have been described (e.g The direct intercostal approach, triangulation, and retrograde percutaneous nephrostomy have all been described)Many urologist favor this approach for gaining access to upper pole and suggest that it provide direct and optimal access to upper pole .Karlin and smith(1989)
892-Triangulation : C arm placed over pt in vertical position retrograde performedskin over desired calyx marked = medial extent of needle penetrationC arm rotated 30 degrees toward surgeon for end on view of calyx, skin site markedmove in vertical line inferiorly to 1-2cm below 12th rib = site of needle entryneedle advanced to junction of vertical plane and 30 degree plane.
90The options for dilation of the tract Fascial dilators. 8fr -36fr rotating, screw- type fashion.Amplatz dilators (blue polyurethane).Alken metal coaxial dilators.for pts with previous surgery and associated fibrous tissueBalloon cathetersmore expensiveDilation of the tract must be performed under fluoro.
91:Stone RemovalStones up to 1 cm in diameter can be grasped using rigid graspers or stone baskets and extracted intact through the 30-F Amplatz sheath .Stones larger than 1 cm require fragmentation before extraction. Several intracorporeal lithotripsy techniques are available .Rigid nephroscopy is the preferred method for stone removal; however, only the simplest intrarenal collecting systems can be completely inspected with a rigid nephroscope via a single access .
92flexible nephroscopy should be used during every PNL to survey the remainder of the kidney for residual stone fragments.The entire collecting system should be examined systematically, including the proximal ureter
93Injection of contrast through the flexible nephroscope is helpful in maintaining orientation and verifying that each calyx has been examined.Small stone fragments can be removed with a 2.2- to 3-F stone basket through the flexible instrument, and larger stones can be fragmented with Laser or EHL .Alternatively, fragments may be flushed or manipulated into the renal pelvis with a combination of high-pressure irrigant and a floppy-tipped J-wire, where they may be retrieved more easily with rigid instruments .
94Postoperative Considerations Nephrostomy Tubetamponade bleeding emanating from the nephrostomy tract,allow the renal puncture to heal.allow proper drainage of urine.allow access to the collecting system if a secondary PNL is required.Nephrostogram 24 to 48 hours post PNL.If all the stones have been removed and there is free flow of contrast down the ureter without extravasation, the nephrostomy tube can be removed or clamped and then removed.
95Percutaneous Nephrolithotomy in Special Situations Pyelocalyceal DiverticulaCalculi in 9.5% to 50% of calyceal diverticula.Direct puncture into the diverticulum allows use of rigid instruments that provide superior visualization compared with flexible instruments in an indirect approach.The neck of the diverticulum is often difficult to identify owing to its typically small size.Methylene blue injected through the ureteral catheter can facilitate visualization of the ostium.Once a guide wire is passed into the renal pelvis, the neck of the diverticulum can be balloon dilated or incised.
96The best sites for access for PCNL in a horseshoe kidney Upper poles: are posterior and lateralinside posterior axillary line just superior to 12th rib.angle inferiorly.most calyces point dorsomedially or dorsolaterally.All blood vessels enter kidney ventrally and medially.May be associated with retrorenal colon get pre-op CT.
97PCNL in Transplanted Kidney The incidence of calculi 0.5-3%The RF for stones in transplantmetabolic abnormalitiesforeign bodies: sutures, stentsrecurrent UTIpapillary necrosisPuncture into a transplant kidney renal pelvis located medially, so posterior calyces point anteriorlyanterior approach similar to posterior approach to native kidneys.pt in lithotomy.access most safely established into lower pole with skin puncture as caudal as possible.
98COMPLICATIONS cessation of procedure placement of NT Blood Losscessation of procedureplacement of NTclamp NT x 10min to allow for tamponnadenephrostomy tamponnade balloon catheterangiography and embolizationnephrectomy: partial
99COMPLICATIONS Perforation of the collecting system 20-30% The cause of this perforation is usually aggressive tract dilatation or the lithotripsy process.Managed by nephrostomy drainage. Within hours, the, given that the collecting system is adequately drained.
100Injury to the Lungthe lung and the pleura are at greatest risk for injury during percutaneous procedures, especially when an intercostal approach is used .increased if supra-11supra-12pneumothorax 4%pleural effusion 8%A postoperative chest X-RAY is necessary to rule out hydrothorax or pneumothorax.If the clinical findings suggest either of these complications, placement of a chest tube is mandatory.Immediate aspiration is performed, and the tube is removed within 24 hours. If the hemothorax is extensive, a large chest tube is advisable.
101colon perforation rare: 0.6% retrorenal colo intraoperative hematocheziaperitonitissepsisgas/feces drainage from NTcontrast seen in colon during post-op nephrostogramplace ureteral catheter or stentwithdraw NT to colon: colostomy tubeleave colostomy tube x 7d, remove after nephrostogram
102Injury to the Spleen and Liver Injury of the spleen and liver are an uncommon finding, especially when the dimensions of the organs are within the normal range.conservative tx after recognitionMonitor with vital signs and serial HgbIf there is persistent bleeding, explore the abdomen
103Extravasation of stones into perinephric space Doudenal injuryTPN,NGT, Gastrograffine swallowExtravasation of stones into perinephric spaceDo nothingAcute loss of the nephrostomy tract: This usually can be avoided by the use of a safety wire.If it occurs, the tract may be probed with a guide wire either in an antegrade or in a retrograde fashion; however, a repeat puncture may be required.
104SepsisSepsis (<1%): Higher rates are noted in those with an infected stone burden.Parenteral antibiotics and nephrostomy drainage are required. Usually, a penicillin- derivative antibiotic and an aminoglycoside are used in combination for initial broad-spectrum coverage.
105OPEN STONE SURGERYThe indications for open removal of ureteral/renal calculistone burden too complete for PCNLsalvage procedure.planned abdominal operation with symptomatic ureteral stone episode.associated anatomic abnormality requiring open repairUPJOinfundibular stenosisureteric abnormality
106OPEN STONE SURGERY Renal Calculi The overall stone-free rate was similar (97% and 96% for PNL and OSS, respectively).PNL offered a shorter hospital staya lower narcotic requirement.a shorter recovery period.PNL was not associated with complications typical for OSS such as wound infection, flank bulge, or prolonged pain and discomfort.Need for perioperative blood transfusion was comparable in both groups
107The AUA committee stated that neither ESWL monotherapy nor OSS should be used as first- line treatment for staghorn stones in most standard patients. As a guideline, PNL, followed by ESWL and/or repeat PNL procedures as warranted, should be used for most standard patients with staghorn calculi .
108Renal Tolerance to Warm Ischemia renal response to warm ischaemiakidney very susceptible to warm ischaemiaimmediately after renal artery occlusion, energy-rich ATP within the kidney breaks down into AMP to provide energy for maintenance of structural and functional cellular integritywarm ischemia up to 30 minutes is toleratedFor periods of warm ischemia beyond 30 minutes, there is generally significant, immediate functional loss, and late recovery of renal function is either incomplete or absent. Histologically, renal ischemia is most damaging to the proximal tubular cellssolitary kidney more resistant
109Prevention of Ischemic Renal Damage When the anticipated period of intraoperative renal ischemia is longer than 30 minutes, additional specific protective measures are indicated to prevent permanent damage to the kidney.Local hypothermia is the most effective and commonly employed method for protecting the kidney from ischemic damage.Lowering renal temperature reduces energy-dependent metabolic activity of the cortical cells, with a resultant decrease in both the consumption of oxygen and the breakdown of adenosine triphosphate
110Prevention of Ischemic Renal Damage Most urologists prefer ice-slush cooling for surface renal hypothermia because of its relative ease and simplicity.An important caveat with this method is to keep the entire kidney covered with ice for 10 to 15 minutes immediately after occluding the renal artery and before commencing the renal operation.
111Ureteral stones ureterolithotomy open or laparoscopic meta-analysis undertaken by the AUA committee revealed median stone-free rates of 87% and 90% for stones in the distal ureter treated by OSS and ureteroscopy, respectively.In the proximal ureter, the stone-free rate for ureterolithotomy was 97%, compared with 83% and 72% for ESWL and ureteroscopy, respectively.OSS for ureteral stones is now indicated only as a salvage procedure, when a planned abdominal operation coincides with a symptomatic ureteral stone episode, or when another ureteral abnormality requires open surgical repair.
112Bladder Stones management The role of ESWL in treating bladder stonespts who are unfit for surgerypts that refuse surgeryusually have retained fragments that require other procedures.
113Bladder Stones management Currently, 3 different surgical approaches to this problem exist. Unlike renal and most ureteral calculi, ESWL has shown little efficacy in most centers.The first approach in adults is transurethral cystolitholapaxy.The second approach in adults (and primary approach in the pediatric population) is percutaneous suprapubic cystolitholapaxyThe third approach, open suprapubic cystostomy to remove the stone(s) intact can be employed with larger and harder stones and when open prostatectomy and/or bladder diverticulectomy are indicated.