No Stone Left Unturned: Percutaneous Nephrolithotripsy in the Radiology Department

Transcription

1 No Stone Left Unturned: Percutaneous Nephrolithotripsy in the Radiology Department Poster No.: C-1720 Congress: ECR 2011 Type: Educational Exhibit Authors: H. Stunell, C. Zwirewich, B. H. Chew, R. F. Paterson; Vancouver, BC/CA Keywords: Abdomen, Gastrointestinal tract, Interventional non-vascular DOI: /ecr2011/C-1720 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 95

2 Learning objectives We review the indications for and contraindications to percutaneous nephrolithotripsy (PNL) We discuss the importance of multimodality imaging in planning the operative approach We review the necessary patient preparation, positioning and access site planning using fluoroscopy and ultrasound prior to PNL We describe standard percutaneous access techniques and discuss more advanced techniques employed in complex cases of urolithiasis such as combined calyceal and ureteral calculi, calyceal diverticula and renal anatomical variants such as horseshoe kidneys, duplex collecting systems and uretero-pelvic junction obstruction We discuss post-procedure care and patient management including postprocedure imaging, stent placement and potential complications We highlight the importance of close interaction between the radiologist and urologist in optimizing stone clearance rates in patients undergoing PNL Background Urolithiasis is a commonly encountered clinical problem, accounting for 7-10 hospital admissions per 1000 in the United States with similar figures reported for the United Kingdom. The main aim of treatment is complete stone clearance however the evolution and refinement of minimally invasive techniques has revolutionized the treatment of urinary tract calculi over the last three decades. The technique of Percutaneous Nephrolithotripsy (PNL) was first described in 1976 by Fernstrom and Johansson [1]. The technique has subsequently been refined, rendering it an effective and safe treatment in the management of urinary tract calculi. Despite similar advances in endourologic techniques and extracorporeal shock wave lithotripsy (ESWL), the role of PNL has expanded greatly, due to a combination of technologic advances and patient factors Page 2 of 95

3 and is now considered the treatment modality of choice for stones greater than 2cm in diameter. Indications: These can be broadly divided into two categories: factors relating to the stone and patientrelated factors. 1. Factors relating to the stone Stone Size: Stone size or "burden" is closely related to stone-free rates and is therefore an important determinant of treatment modality Guidelines of the European Association of Urology recommend the use of PNL as the primary treatment modality for all stones greater than 2cm in diameter [2] Staghorn calculi: Page 3 of 95

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5 Fig.: Figure 1: Pre PNL radiograph demonstrating large staghorn calculus forming a cast of the entire renal pelvis and calyceal system on the right. The staghorn calculus was completely cleared with PCNL. Treatment of choice for patients with staghorn calculi American Urological Association (AUA) [3] found Higher stone free rates for PNL compared to open surgery for staghorn calculi (78% v 71%) Higher stone free rates for combined approach PNL & ESWL for staghorn calculi v ESWL alone Lower number of mean procedures necessary for treatment when PNL was used either alone or in combination with ESWL than for ESWL or open surgery alone PNL associated with lower morbidity (16% v 37%) and shorter in-patient hospital stay (4 v 6 days) when compared with open surgery for the treatment of staghorn calculi [4] Stone Location: PNL is the treatment modality of choice for lower pole calyceal stones Stone free rates have been shown to be higher for lower pole calyx stones >1cm treated with PNL v ESWL (85-90% v 50-56%) in a number of retrospective studies [5, 6, 7] Randomized controlled trial has shown that stone free rates dropped as low as 21% for calculi >1cm treated with ESWL [8] Lower pole stones treated with PNL have a lower recurrence rate one year post treatment than those treated with ESWL (4% v 22%) [6] PNL may also be used for large calculi in the proximal ureter with higher reported stone free rates compared to ureteroscopy (95% v 58%) [9] Stone composition: Renal calculi can be rendered highly resistant to fragmentation by their chemical composition Such calculi pose significant difficulty for treatment with ESWL. Examples include either very hard (cystine, calcium monohydrate, brushite) or very soft stones (uric acid and matrix stones) Page 5 of 95

6 Soft stones, in addition to being resistant to fragmentation due to their puttylike consistency, are radioloucent and thus difficult to target fluoroscopically at ESWL Struvite calculi result from chronic urinary tract infection (UTI) with ureasplitting organisms e.g. Proteus and Klebsiella, and due to the presence of foreign bodies in the urinary tract which become encrusted and act as a nidus for stone formation In such cases, PNL provides the best treatment option for complete eradication of stone burden Stones in patients with anomalies of the renal tract (congenital or acquired) A number of congenital anomalies of the urinary tract are associated with impaired drainage and therefore a low probability of successful passage of stone fragments following ESWL Horseshoe kidneys Calyceal diverticula Page 6 of 95

7 Fig.: Figure 2: Control radiograph obtained during PNL demonstrates right retrograde ureteral catheter in situ. A 1.5cm cluster of tiny calculi is visualised overlying the upper pole of the right kidney, within a calyceal diverticulum. Page 7 of 95

8 Fig.: Figure 3: Opacification of the stone-bearing calyceal diverticulum and its communicating infundibulum (arrow) is achieved following injection of dilute contrast via the ureteral catheter. The diverticulum is then punctured under fluoroscopic guidance using an 18 Gauge Chiba needle. Page 8 of 95

9 Ectopic kidneys Fused kidneys Transplant kidneys Fig.: Figure 4: Control radiograph from PNL demonstrating surgical clips overlying the right iliac fossa from prior renal transplant. A 1.5cm radiopaque calculus is present within a lower pole calyx. Page 9 of 95

10 Fig.: Figure 5: Successful puncture of the lower pole of the right iliac fossa transplant was achieved using an 18G Chiba needle. Dilute contrast was then injected to opacify the ureter and bladder. Stones in obstructed systems requiring simultaneous correction e.g. pelviureteric obstruction (PUJO) Page 10 of 95

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12 Fig.: Figure 6: Retrograde catheter in situ which has been used to opacify the collecting system, demonstrating typical PUJ obstruction configuration. Multiple small calculi are identified in the lower pole and interpolar calyces. 2. Factors relating to the patient Urinary diversion: Approximately 10% of ileal conduits are associated with the development of calculi Retrograde access is typically challenging for the urologist and stone clearance rates of up to 100% are reported for this patient subgroup when treated with PNL [10] Page 12 of 95

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14 Fig.: Figure 7: Spot fluoroscopic image from a PNL procedure demonstrating tip of 30 French sheath (small arrow) in the renal pelvis with an internal/external ureteral stent in situ with its distal tip in the ileal conduit (large arrow). Skeletal malformations: May be a suitable alternative in patients with severe scoliosis, contractures or spina bifida in whom treatment with ESWL is not feasible due to limitations posed by ineffective coupling with the shockwave head Obesity: Increasing trends towards patient obesity in Western populations imposes significant limitations on the use of ESWL e.g. imaging resolution, weight limit for fluoroscopy table. In addition, increased "skin to stone" distance limits the effectiveness of ESWL with success rates as low as 57% reported [11] Surprisingly, many studies have shown that BMI does not affect PNL in terms of duration of hospital stay and complications with similar stone free rates reported as with non-obese populations [12] Occupation: The diagnosis of renal tract calculi in some professions such as commercial and military pilots, even if asymptomatic, results in immediate cessation of flight duties until treated Several centres have found PNL to minimize the work-time lost and result in the highest rates of stone clearance [13] Contraindications: Few absolute contraindications to PNL exist. These include: Untreated coagulopathy Hydatid cyst Relative contraindications include: Pregnancy Concurrent urosepsis Non-functioning kidney Page 14 of 95

15 Anaesthetic co-morbidity Lack of safe percutaneous access e.g. overlying colon Principles of PNL access: Aims: The aim of PNL is to produce complete stone clearance If complete clearance is not technically feasible Clear the renal pelvis to improve drainage Clear the stone burden from the lower pole calyces preferentially, as these are less likely to respond to ESWL Calculi remaining in the upper or interpolar calyces can later be treated with ESWL Access: Anterior calyces can be accessed via a posterior calyx puncture Anterior calyceal entry makes intrarenal navigation more difficult Upper pole access while associated with a higher rate of vascular and pleural injury, allows access to the pelvi-ureteric juction and upper ureter The fornix is the ideal puncture site for PNL access. The risk of vessel dilation associated with 30 Fr dilation is [14]: <8% venous injury, 0% arterial injury for fornix 33% for renal pelvis 38% for interpolar infundibulum 68% for both the upper and lower infundibulum Interpolar access This requires greater torque forces to reach the upper and lower poles and is associated with 3.5 times the rate of complications Should be used selectively for specific indications e.g. stone-bearing calyceal diverticula & staghorn calculi Supracostal access Use ultrasound to mark the lung, liver/spleen prior to puncture Avoid the paraspinal muscle Reduce the tidal volume to move the aerated lung out of the access field Page 15 of 95

16 Dilation: Dilation should be performed only as far as the fornix Page 16 of 95

17 Fig.: Figure 8: Spot fluoroscopic image demonstrating balloon dilatation being performed beyond the fornix. Fig.: Figure 9: Balloon dilatation is optimal in this case, being performed just as far as the fornix. Page 17 of 95

18 Care should be taken not to over-advance the sheath and advancement should therefore be performed under fluoroscopic guidance There should be a low threshold for insertion of a second tract if the first is sub-optimal Imaging findings OR Procedure details Multimodality Imaging: ABDOMINAL RADIOGRAPHS majority of urinary tract calculi are calcium-containing and should therefore be visible on plain radiographs Page 18 of 95

19 Fig.: Figure 10: Pre PNL radiograph demonstrates bilateral internal ureteral stents. The proximal left ureter contains an ovoid 2.6 X 0.9cm stone at the UPJ, with three additional smaller calculi in the lower pole measuring up to 5mm. On the right, there is a 2.1 X 1.5cm stone in the renal pelvis as well as multiple additional smaller stones measuring up to 9mm in the lower pole. The patient subsequently underwent bilateral PNL. Page 19 of 95

20 bowel gas, faecal material in overlying colon, patient obesity and extra-renal calcifications limit detection overall low sensitivity in recent studies for detection of calculi, ranging from 45-58% [15] Nonetheless, plain radiographs retain a central role in monitoring known radiopaque calculi and in planning fluoroscopically-guided therapeutic procedures such as PNL and ESWL ABDOMINAL CT Over 99% of stones will be visualized on non-contrast stone protocol CT (CT KUB) [16] Unrivalled diagnostic accuracy, visualizing the site and allowing accurate measurement of size of the calculus, however cranio-caudal size may be overestimated by spiral CT Visualizes calculi that are radiolucent on plain radiographs with the exception of indinavir and pure matrix stones Page 20 of 95

21 Fig.: Figure 11: Plain abdominal radiograph demonstrates right double J ureteral stent. No radiopaque urinary tract calculus is visualized. Page 21 of 95

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24 Fig.: Figure 12: CT KUB image in the same patient demonstrating 1cm ovoid calculus in the right renal pelvis (arrow) which was radiolucent on the preceeding plain radiograph Assesses for the presence and severity of obstruction Fig.: Figure 13: CT KUB demonstrates bilateral hydronephrosis in a horseshoe kidney secondary to obstructing calculi in both lower poles Allows measurements of "stone density", which has been used as a predictor of stone response to ESWL [17] Multiplanar reformations (MPR) and volumetric 3D reconstructed images provide additional anatomical information to assist in planning the optimal percutaneous approach Page 24 of 95

25 CT ANGIOGRAPHY May be necessary in certain situations when PNL is being planned for patients with congenital anomalies such as horseshoe, ectopic, crossed fused ectopia and PUJ obstruction to evaluate for the presence of aberrant arterial supply and in the case of PUJ obstruction, to exclude the presence of a crossing vessel Page 25 of 95

26 Fig.: Figure 14: Coronal reformatted image from a CT renal angiogram in a patient with congenital PUJ obstruction being evaluated for PNL. This demonstrates the Page 26 of 95

27 proximal end of an internal ureteral stent beyond the UPJ stricture in the grossly dilated renal pelvis. Two stones are identified, one in an upper pole calyx and the larger stone in the renal pelvis measuring 2cm in diameter. Page 27 of 95

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29 Fig.: Figure 15: Reformatted image from a CT renal angiogram in the same patient shows that no crossing vessel is present in this case. Page 29 of 95

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31 Fig.: Figure 16: Reformatted image from CT renal angiogram in a patient with PUJ obstruction illustrating the presence of anterior impingement caused by an accessory renal artery. Page 31 of 95

32 Fig.: Figure 17: Reformatted image from a CT renal angiogram in the same patient demonstrates the presence of an accessory renal artery (arrow) causing anterior Page 32 of 95

33 impingement at the PUJ. It is crucial that the presence of a crossing vessel (even though uncommon) is appreciated prior to tract planning in cases of PUJ obstruction and a CT renal angiogram should be considered mandatory in patients with PUJ obstruction who are being evaluated for possible PNL. CT UROGRAPHY Fig.: Figure 18: Axial image from the delayed phase of a CT Urography study demonstrates multiple filling defects within the dilated collecting system of a horseshoe kidney (arrows). Reconstructed images from the delayed phase of a multislice CT urographic study elegantly depict the collecting system anatomy [18] May prove invaluable in pre-treatment planning of a number of complex anatomical variants e.g. calyceal diverticula, horseshoe kidneys Page 33 of 95

34 Fig.: Figure 19: 3D reformatted image from a 5 minute delayed phase of a CT urography study in a patient with a horsehoe kidney (same patient as above axial CT image). This elegantly depicts the stone distribution and calyceal anatomy and aids in planning percutaneous access. Page 34 of 95

35 Fig.: Figure 20: Tract planning and ultimately, complete stone clearance in this patient with complex bilateral stone burden in a horsehoe kidney was facilitated by preoperative CT urography with 3D reformatted images. ULTRASOUND Page 35 of 95

36 Fig.: Figure 21: Sagittal ultrasound image of the right moiety of a horseshoe kidney demonstrates large calculi (arrows) at the lower pole causing upper pole hydronephrosis. Ultrasound is widely used by the interventional radiologist both prior to and during percutaneous tract access Its value lies in its ability to provide real-time information regarding position of liver, spleen and colon and in its utility in assessing the lowermost extent of the aerated lung when planning upper tract punctures Can be utilized in conjunction with fluoroscopy to establish access into the desired calyx Procedure Details: Preview of PNL imaging Assess the adequacy of current imaging i.e. is it really a stone? Page 36 of 95

37 Fig.: Figure 22: Plain abdominal radiograph in a patient referred for PNL due to a presumed right renal calculus which was resistant to ESWL. Page 37 of 95

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39 Fig.: Figure 23: CT KUB in the above patient demonstrating that the presumed right renal calculus actually represents a calcified gallstone within the gallbladder lumen. Fig.: Figure 24: Axial CT image from a stone protocol CT demonstrates the left collecting system has been entirely replaced by high attenuation material, thought originally to have represented a large staghorn calculus. The patient was referred to our institution for PNL. Page 39 of 95

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41 Fig.: Figure 25: Coronal reformatted image demonstrating lower attenuation material centrally within the collecting system without any residual demonstrable renal cortex. The features are suggestive of end-stage TB kidney or "putty kidney". The patient instead underwent a left nephrectomy. The operative specimen is shown below. Fig.: Figure 26: Operative nephrectomy specimen bivalved to demonstrate the entire collecting system replaced by soft, putty like material producing the so-called "TB autonephrectomy". Assess safety of access Page 41 of 95

42 Fig.: Figure 27: Plain abdominal radiograph demonstrates a large calculus in the left renal pelvis. Significant bowel gas overlies both flanks. Page 42 of 95

43 Fig.: Figure 28: CT confirms significant colonic interposition. No safe access was available and PNL of the large calculus in the left renal pelvis was not technically feasible. Obtain additional imaging as required e.g. CT urography desirable in ectopic and horseshoe kidneys Review renal anatomy and stone distribution Page 43 of 95

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45 Fig.: Figure 29: Ampullary type system containing large stone burden. The fornices and infundibula are large, making these systems more amenable to PNL. Page 45 of 95

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47 Fig.: Figure 30: Dendritic system with an associated lower pole calyceal diverticulum. These systems are technically difficult for PNL as their fornices are narrow with long and slender infundibula. Page 47 of 95

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49 Fig.: Figure 31: Transitional system has features of both the ampullary and dendritic systems as seen above. Plan access i.e. single or multiple, upper, lower or interpolar Fig.: Figure 32: Multiple bilateral calculi in a patient with medullary nephrocalcinosis referred for PNL. Page 49 of 95

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51 Fig.: Figure 33: Right retrograde pyelogram in the above patient demonstrates multiple calculi in a bifid dendritic system. An upper pole access had initially been planned however multiple tracts were ultimately required intraoperatively in order to achieve maximum stone clearance (see below). Fig.: Figure 34: Spot fluoroscopic image in the above patient demonstrating three PNL tracts in each kidney. Assess whether anatomic modifiers make placement of a retrograde catheter necessary e.g. lucent stone, obese patient, calyceal diverticulum or PUJ obstruction Ideally, the approach should be discussed with the Urologist prior to commencing tract access to maximise stone clearance rates Patient preparation & positioning Page 51 of 95

52 Anticoagulation status is reviewed Fig.: Figure 35: Guidelines for stopping anticoagulation medications in patients undergoing PNL. References: SIR JVIR 2009; 20:S240-S249 Procedure performed under general anaesthetic Reviewed by anaesthetist prior to procedure Routine haematological and coagulation parameters including full blood count and coagulation parameters including INR Patient intubated and turned prone Perioperative antibiotic prophylaxis is administered Access site planning Localizing ultrasound performed to identify: lung in cases of upper pole puncture colon liver/spleen Page 52 of 95

53 Fig.: Figure 36: The liver, spleen and pleura are marked pre-operatively. Standard tract access With the patient prone on the C-arm fluoroscopy table, fluoroscopic triangulation technique is employed to access the desired calyx Page 53 of 95

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55 Fig.: Figure 37: Fluoroscopic image demonstrating large staghorn calculus with retrograde ureteral catheter in situ and planned upper pole calyceal access marked by forceps. With the C-arm directed parallel to the needle, adjustments are made in the medial and lateral directions only while the C-arm is rotated in a cranial and caudal direction. The depth of the needle is adjusted while the C-arm is rotated obliquely in the sagittal plane This technique requires that the needle orientation should be maintained constant in one plane while adjustments are made in the other plane In cases where difficult access is anticipated, initial access into the collecting system can be attempted using a 22 G needle to opacify the system with contrast Definitive access is then achieved using an 18 G needle. Alternatively, in more straightforward cases, direct access can be attempted using the 18 G needle A 5Fr angle-tipped catheter is used to manipulate a guidewire down the ureter and into the bladder The needle is then removed and an 8 French sheath is positioned so that its distal tip lies within the proximal ureter and through this sheath a second safety wire is inserted The 8 French sheath is removed and balloon dilatation of the tract up to 30 French is performed, thus forming the PNL access tract Page 55 of 95

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57 Fig.: Figure 38: Spot fluoroscopic image demonstrating successful upper pole calyceal access with "safety" and "working" wires which have been negotiated successfully beyond the large staghorn calculus, down the ureter and into the bladder. Balloon dilatation of the tract over the "working" wire up to 30F is illustrated. Over the inflated balloon, a 30 French access sheath is positioned within the calyx and the balloon is removed, following fixation of the guidewires in situ Page 57 of 95

58 Fig.: Figure 39: Spot fluoroscopic image demonstrating two guidewires and 30F sheath in situ. A flexible nephroscope (arrow) has been advanced via the sheath into the tract, allowing direct endoscopic assessment of the calyces. Under direct nephroscopic visualization, as illustrated above, the stone burden is removed using fluoroscopic guidance Fig.: Figure 40: Final image demonstrating 30F sheath and safety wires in situ with complete clearance of the large staghorn calculus achieved. Page 58 of 95

59 Catheter options: If patient is stone-free post procedure and there is no excessive bleeding, a 5 Fr DAV "safety" catheter plus either 8-10 Fr nephrostomy or 12 Fr silastic Foley catheter If patient is stone-free post procedure with moderate bleeding, an 8 Fr internal/external stent plus 20 Fr Council Foley + 5 Fr DAV If patient is stone-free and there is either urosepsis or a urine leak, an 8 Fr internal/external stent is left in situ If access is supracostal, internal ureteric stent plus 5 Fr DAV or 8-10 Fr nephrostomy If gross residual stone or pyonephrosis, 5 Fr DAV "safety" catheter plus 20 Fr Council Foley or 20 Fr Malecot catheter Page 59 of 95

60 Fig.: Figure 41: Post PNL demonstrating 8.5 F pigtail nephrostomy tube in situ (arrow). Page 60 of 95

61 Special access situations Obesity: Page 61 of 95

62 Fig.: Figure 42: Scout image from pre-pnl CT in a morbidly obese patient. Fig.: Figure 43: Axial non-contrast CT in a morbidly obese patient who weighed 445 pounds who underwent successful PNL for treatment of multiple large calculi in the right renal pelvis and lower pole calyces. Morbidly obese patients may exceed the weight limit for ESWL Upper pole access is often preferred due to shorter skin to stone distance A retrograde catheter may prove invaluable in facilitating opacification of the collecting system and calculus and thus aiding percutaneous access Page 62 of 95

63 Retained foreign body: Stent fragments, guidewires and threads from percutaneous nephrostomy tubes can occasionally be encountered in urological practice These act as a nidus for stone formation and frequently present with recurrent UTI Page 63 of 95

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65 Fig.: Figure 44: Coronal reformatted image demonstrating retained basket device that has become wrapped around a calculus in a lower pole calyx. This could not be retrieved at ureteroscopy. A retrograde catheter is recommended cases of retained foreign bodies to facilitate opacification of the collecting system Fig.: Figure 45: Retrograde pyelogram in the same patient illustrates retrograde catheter in situ (small arrow) which has been used to opacify the collecting system with contrast. The retained basket and wire are also seen (large arrow). Page 65 of 95

66 If the foreign body is situated in the renal pelvis, a lower pole puncture is recommended If it is located in a peripheral calyx, the specific calyx is targeted Fig.: Figure 47: Spot fluoroscopic image from the same case demonstrating selective access using an 18 G needle into the lower pole calyx containing the retained basket and stone. Page 66 of 95

67 Fig.: Figure 48: The tract has been balloon dilated up to 30 Fr and a 30 Fr sheath has been left in situ. Page 67 of 95

68 Fig.: Figure 49: Endoscopic view inside the collecting system demonstrating retained basket and wire which was successfully retrieved during PNL. A "mini PNL" with a Fr sheath may be adequate for foreign body retrieval Calyceal diverticula: PNL is the ideal treatment for patients with stone-bearing calyceal diverticula as it allows stone removal and ablation of the diverticular cavity [14]. Page 68 of 95

69 PNL is associated with high stone clearance rates (93-100%) and successful obliteration of the diverticular cavity (76-100%) with a single procedure [19]. CT is the preferred modality for planning PNL and a retrograde catheter should be placed at the time of PNL to allow retrograde filling of the calyceal diverticulum and opacification of its connecting infundibulum Fig.: Figure 50: Spot fluoroscopic image demonstrates successful access into the stone-bearing lower pole calyceal diverticulum using an 18G needle. Through the needle, a hydrophilic guidewire was negotiated across the connecting infundibulum and positioned within the renal pelvis Page 69 of 95

70 Fig.: Figure 51: Spot fluoroscopic image demonstrating 5 Fr DAV catheter advanced into the diverticulum, across the infundibulum and into the renal pelvis. Page 70 of 95

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72 Fig.: Figure 52: Following positioning of a standard J wire into the renal pelvis, down the ureter and into the bladder, an 8 Fr sheath was positioned with its distal tip in the proximal ureter and a second "safety wire" was advanced into the urinary bladder. Tract dilation up to 30 Fr was performed as shown and a 30 Fr sheath was left in situ. The communicating neck of the diverticulum was successfully marsupialized following percutaneous stone clearance. In cases in which the "communicating" neck or infundibulum can be successfully crossed, this can be marsupialized If the neck cannot be demonstrated or is demonstrated but cannot be crossed, it is considered a "non-communicating" diverticulum and thermal ablation is performed PUJ obstruction with calculi: 20% of patients with PUJ obstruction develop calculi In carefully selected patients with PUJ obstruction, PNL combined with endopyelotomy can have success rates of up to 90%, facilitating stone clearance and correction of the obstructed drainage at a single procedure A CT renal angiogram should always be performed prior to PNL A retrograde catheter should be placed prior to the procedure to facilitate filling of the renal pelvis and calyceal system with contrast Upper pole access is optimal Page 72 of 95

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74 Fig.: Figure 53: A retrograde catheter is placed prior to PNL. Fig.: Figure 54: The renal pelvis has been successfully opacified with contrast via the retrograde cathter demonstrating a typical PUJO configuration. Page 74 of 95

75 A retrograde guidewire is advanced beyond the the PUJ into the renal pelvis and snared prom the percutaneous access point Page 75 of 95

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77 Fig.: Figure 55: A guidewire has been advanced retrogradely into the renal pelvis and is being snared via the percutaneous access tract. Page 77 of 95

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79 Fig.: Figure 56: The guidewire is snared and brought back into the percutaneous access tract. Fig.: Figure 57: The tract is then laid in the usual fashion over the guidewire following balloon dilation up to 30 Fr. All patients in our unit undergo a routine non-contrast CT on the first post-operative day to assess for stone clearance Complications: Page 79 of 95

80 COMPLICATION % of all cases done All minor complications 15.3% Pleural effusion 9.3 Emergency room visit post-op 7.0 UTI 6.9 Collecting system perforation 3.1 Pneumonia 1.6 Pneumothorax (no chest tube) 0.5 Urosepsis without ICU admission 0.5 Hydrothorax 0.4 Haemothorax 0.3 Pulmonary embolism 0.3 Renopleural fistula VGH Minor Complications 0.3 COMPLICATION % of all cases done All major complications 8.3 Bleeding requiring transfusion 3.4 Angioembolization 0.9 Large pleural effusion/empyema requiring 0.8 chest tube Urosepsis with ICU admission 0.7 Pleural decortication 0.4 MI, DVT, exploratory laparotomy VGH Major Complications 0.4 Page 80 of 95

81 Fig.: Figure 58: Post PNL CT demonstrates extravasation of contrast from the anteromedial wall of the renal pelvis following an intraoperative perforation. References: H. Stunell; Radiology, University of British Columbia and Vancouver Page 81 of 95

82 Fig.: Figure 59: Antegrade nephrostogram demonstrates almost complete resolution of urine leak 24 hours following percutaneous nephrostomy drainage. Page 82 of 95

83 Fig.: Figure 60: Selective right renal artery angiogram in a patient undergoing elective PNL. Following balloon dilation of the tract up to 30 Fr, significant bleeding occurred via the sheath. This failed to tamponade on re-inflation of the balloon and the patient proceeded to angiography. 5 Fr catheter is present within the main renal artery (small arrow). There is active extravasation of contrast from a lower pole branch of the renal artery which is seen refluxing along the inflated balloon (large arrow) and out the tract. Successful selective embolization of the bleeding vessel was performed. Page 83 of 95

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85 Fig.: Figure 61: Bifid system with upper and lower pole calculi requiring upper and lower pole access tracts. Fig.: Figure 62: Upper and lower pole access was performed. On fluoroscopic imaging, the upper pole access was thought to be supra-11th rib. Page 85 of 95

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87 Fig.: Figure 63: Reformatted image from post-procedure CT demonstrates that the upper pole access was in fact supra-10th and transgressed the spleen. The patient was asymptomatic. Fig.: Figure 64: All tubes and catheters were left in situ for one week. The patient was brought to the Interventional Radiology suite for tube removal following catheterization of the splenic artery in the event emergency embolization was necessary. Page 87 of 95

88 Fig.: Figure 65: Splenic artery angiogram showed no evidence of extravasation and the nephrostomy was removed uneventfully. Page 88 of 95

89 Fig.: Figure 66: Upper and lower pole access was obtained for PNL of a large stone burden in the right kidney. Page 89 of 95

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91 Fig.: Figure 67: During the procedure, the patient became progressively difficult to ventilate. The chest was screened with fluoroscopy demonstrating a large right hydrothorax. Fig.: Figure 68: An 8 Fr pigtail catheter (arrow) was inserted under ultrasound guidance to drain the large right effusion. Supracostal puncture is associated with a 15% risk of hydrothorax compared with 1.4% when a subcostal approach is used. On table fluoroscopy of the thorax provides quick assessment in cases where the patient suffers compromised respiratory status during PNL, particularly in upper pole punctures. Page 91 of 95

92 Conclusion Fig.: Stone Centre Since the opening of a dedicated the Stone Centre at Vancouver General Hospital, significant improvements in rates of major complications, including transfusion rates and pulmonary complications as well as improvements in stone free status have been achieved Page 92 of 95

93 Percutaneous Nephrolithotripsy is a safe and effective treatment for large calculi and those refractory to other treatment modalities A co-operative, integrated relationship between the radiologist and urologist optimizes patient care and stone-free rates Complications can be minimized by strict adherence to basic anatomic priciples Recommended in the Guidelines of the European Association of Urology for treatment of the following: large stones >2cm in size or >1.5cm for stones in a lower pole calyx staghorn calculi stones resistant to fragmentation by ESWL due to their composition e.g. cystine, calcium oxalate monohydrate stones that have proven refractory to ESWL or ureteroscopy congenital malformations with low probability of successful passage of stone fragments following ESWL e.g. horseshoe kidney, ectopic kidney, calyceal diverticula patient obesity stones in obstructed systems that require simultaneous correction. This includes cases of ureteropelvic junction obstruction with associated calculi, where the patient can be rendered stone-free and undergo endopyelotomy with ureteric stenting as a single stage procedure with PNL Personal Information References Fernstrom I, Johansson B. Percutaneous pyelolithotomy. A new extraction technique. Scand J Urol Nephrol 1976;10: Tiselius HG, Alken P, Buck C, Gallucci M, Knoll T, Sarica K, Turk C. Guidelines on urolithiasis. European Urological Association, 2008 Preminger GM, Assimos DG, Lingeman JE, Nakada SY, Pearle MS, Wolf JS Jr. AUA Nephrolithiasis Guideline Panel. Chapter 1: AUA guideline on management of staghorn calculi: Diagnosis and Treatment Recommendations. J Urol 2005; 173: Page 93 of 95

94 Al-Kohlany KM, Shokeir AA, Mosbah A, Mohsen T, Shoma AM, Eraky I, El-Kenawy M, El-Keppany HA. Treatment of complete staghorn stones: A prospective randomized comparison of open surgery versus percutaneous nephrolithotomy. J Urol 2005; 173: Lingeman JE, Siegel YI, Steele B, Nyhuis AW, Woods JR. Management of lower pole nephrolithiasis: A critical analysis. J Urol 1994; 151: Carr LK, D'A Honey J, Jewett MA, Ibanez D, Ryan M, Bombardier C. New stone formation: A comparison of extracorporeal shock wave lithotripsy and percutaneous nephrolithotomy. J Urol 1996; 155: Chen RN, Streem SB. Extracorporeal shock wave lithotripsy for lower pole calculi: long term radiographic and clinical outcome. J Urol 1996; 156: Albala DM, Assimos DG, Clayman RV et al. Lower pole I: A prospective randomized trial of extracorporeal shock wave lithotripsy and percutaneous nephrostolithotomy for lower pole nephrolithiasis - initial results. J Urol 2001; 166: Juan YS, Shen JT, Li CC, Wang CJ, Chuang SM, Huang CH, Wu WJ. Comparison of percutaneous nephrolithotomy and ureteroscopic lithotripsy in the management of impacted, large, proximal ureteral stones. Kaohsiung J Med Sci 2008;24: Cohen TD, Streem SB, Lammert GK. Selective minimally invasive management of calculi in patients with urinary diversions. J Urol 1994; 152: Perks AE, Schuler TD, Lee J, Ghiculete D, Chung DG, D'A Honey RJ, Pace KT. Stone-attenuation and skin-to-stone distance on computed tomography predicts for stone fragmentation by shock wave lithotripsy. Urology 2008; 72: Bagrodia A, Gupta A, Raman JD, Bensalah K, Pearle MS, Lotan Y. Impact of body mass index on cost and clinical outcomes after percutaneous nephrolithotripsy. J Urol 2008; 72: Zheng W, Beiko DT, Segura JW, Preminger GM, Albala DM, Denstedt JD. Urinary calculi in aviation pilots: What is the best therapeutic approach? J Urol 2002; 168: Miller NL, Matlaga BR, Lingeman JE. Techniques for fluoroscopic renal access. Journal of Urology 2007; 178: Sandhu C, Anson KM, Patel U. Urinary tract stones - Part I: Role of Radiological Imaging in Diagnosis and Treatment Planning. Clin Rad 2003; 58: Smith RC, Coll DM. Helical computed tomography in the diagnosis of ureteric colic. BJU Int 2000; 86:33-41 Page 94 of 95

95 17. Joseph P, Mandal AK, Singh SK et al. Computerized tomography attenuation value of renal calculus: can it predict successful fragmentation of the calculus by extracorporeal shockwave lithotripsy? A preliminary study. J Urol 2002; 167: Patel U, Walkden RM, Ghani KR, Anson K. Three-dimensional CT pyelography for planning of percutaneous nephrostolithotomy: accuracy of stone measurement, stone depiction and pelvicalyceal reconstruction. Eur Radiol 2009; 19(5): Monga M, Smith R, Ferral H, Thomas R. Percutaneous ablation of calyceal diverticulum: long-term follow up. J Urol 2000; 163:28 Page 95 of 95