Percutaneous nephrolithotomy-a versatile technique for both simple and complex renal stone

Percutaneous Nephrolithotomy is currently the preferred first line treatment for simple & complex renal calculi. The technique also being used increasingly for smaller stones that have failed ESWL. Aim of the study is to share our experience in PCNL in course of time. This study was conducted from January 2009 to December 2012, 131 patient’s with142 renal units of 5-75 yrs of age, PCNL were performed in NIKDU, BSMMU & JBFH. Stone were classified into simple (isolated renal pelvis or isolated calyceal stones) or complex (partial or complete staghorn stones, renal pelvic stone with accompanying calyceal stones). The stone size was 1.5-5cm approximately. We asses our initial puncture technique, need for multi-tract, supra 12 rib access, stone free rate, operative duration, postoperative complication, number of transfusion and hospital stay. Operative durations were 60 min -180 minutes. Puncture technique improved in course of time. 14 patients need multi-puncture and tract, all are supra 12 access. Out of 142 renal units 120 (83%) were stone free after first procedure, another 22 need and auxiliary procedure, (5 2nd look PCNL, 6 URS, 11 ESWL) to become stone free result in a 95% stone free rate. Complications occurred in 17 procedures which dealt accordingly. This study revealed PCNL is an effective, versatile safe and cosmetically acceptable procedure for all age groups in simple and complex renal stone.


Introduction
The advent and continuous evolution of percutaneous nephrolithotomy (PCNL) have led to a revolution in the management of renal stones 1,2 .PCNL is now the preferred treatment for patients with renal calculi and is a safe and successful method used for removal of different types of stones 3 .The technique is also being used increasingly for smaller stones that have failed Extra Corporeal Shockwave lithotripsy (ESWL) or where in the anatomy of the collecting system would likely result in a lesser chance of success with ESWL.The morbidity of PCNL is less than that open surgery with better stone-clearance rates 4,5 .With increasing stone size and complexity, PCNL may require a longer operative time, larger volumes of irrigant fluid, and multiple tracts to achieve complete stone clearance 6 .
The traditional subcostal access is preferred in percutaneous renal surgery to avoid injury to the lungs and pleura 7 .However, in some patients, such as those with upper calyceal stones, impacted upper ureteral stones, staghorn calculi, and in obtaining access to the ureteropelvic junction (UPJ), the supracostal approach may be the most direct means to achieve a satisfactory result.The supracostal approach used to be avoided for fear of potential chest complications.However, knowledge of the pleural and diaphragmatic anatomy and refinement of the surgical technique have reduced these complications to a minimum.Now a days, PCNL should be the first-line treatment for large or multiple kidney stones and stones in the inferior calyx.Furthermore, improvements in instruments (i.e., nephroscopes and ureteroscopes) as well as lithotripsy technology (i.e., ultrasound/pneumatic devices, holmium/ yttrium-aluminum-garnet laser) increased the efficacy of percutaneous stone disintegration yielding stone-free rates of >90% 8, 9 .
PCNL is generally a safe treatment option and associated with a low but specific complication rate 10 .Many complications develop from the initial puncture with injury of surrounding organs (e.g., colon, spleen, liver, pleura, and lung).Other specific complications include postoperative bleeding and fever.
Based on personal experience and an overview of the literature, we present PCNL as a step-by-step approach including the stone clearance, the description of possible complications and their origin and management adequately.

Materials and Methods
From January 2009 to December 2012, 131 patients with142 renal units of 5-75 years of age, male 75 and female 67 ( Stone were classified into simple (isolated renal pelvis or isolated calyceal stones) (Fig. 1A) or complex (partial or complete staghorn stones, renal pelvic stone with accompanying calyceal stones) (Fig. 1B, 1C).The stone size was 1.5-5cm approximately.Simple stone 109, Complex stone 33 and B/L stone 11.

Procedural technique.
All PCNL procedures were performed in a teaching environment using the same technique under general anesthesia and a few cases under Sub Arachnoid Block (SAB).At first, patient placed in lithotomy position and retrograde access was obtained with ureteric catheter over guide wire.Then ureteral catheter was secured to a Foley catheter.The patient was repositioned prone with adequate padding under the pressure points of the head, chest, knees, and feet.Percutaneous access was obtained at the time of surgery by the operating urologist in all 142 cases, without assistance from interventional radiology guidance.Based on the stone location, size, burden, and pelvicalyceal anatomy, the site of calyceal entry and number of access tracts were chosen at the procedure's commencement.
The architecture of the collecting system was delineated by contrast infused through the ureteral catheter with the patient supine.Two images are captured: One in the anterior-posterior plane and another in 30-degree lateral images.A bull's-eye technique was used to gain access directly into the center of the papilla of the chosen calyx, once the patient was placed in the prone-flexed position.Once intrarenal access is obtained, the tract is sequentially dilated from 6F to 30F, and a safety guide wire is inserted (Fig. -2A).
The tract was dilated to 30Fr under fluoroscopic guidance, and access into the collecting system is confirmed by rigid nephroscopy.Once access was gained, pneumatic and ultrasonic lithotripter was used to fragment the stone.Tri-radiate forceps (Storz) are used to render the patient stone free.All 14 patients with supracostal access underwent fluoroscopy of the chest to exclude hydrothorax.Standrad PCNL (for adult) & mini -PCNL (for children) done.For adult tract size 28-30 Fr & 16/24 Fr tract for children.5Fr/6Fr JJ stent placed in situ after procedure, every calyx was checked at the end of the procedure, residual stones were either within papillae or small and inaccessible via the available tract or tracts, where it was considered unreasonable to insert an additional tract.14/20/26FR Nephrostomy tube kept in situ after procedure (Fig. 2B).Postoperatively, the nephrostomy tube was removed after 24 hour.We asses our initial puncture technique, need for multitract, supra 12 th access, stone free rate, operative duration, postoperative complication, number of transfusion and hospital stay.

Results
In our 142 renal units, the PCNL was on the right side in 85 and on the left side in 57.Renal access was obtained lower posterior calyceal puncture in 101, middle calyceal puncture 27 and above the twelfth rib in 14 (9 preplanned, 5 as 2 nd puncture) procedures (Fig. 3).Operative time ranged between 60-180 minutes, with a mean of 90.83±29.13minutes.

Fig.- 3 :
Fig.-3: Puncture SiteA renal unit was considered stone free when the postoperative radiograph of kidneys, ureters, and bladder (KUB) showed no or clinically insignificant stone fragments (<2mm).116 renal units were rendered free of stone material (82%), as evidenced by intraoperative fluoroscopy and postoperative KUB radiography and/or ultrasonography after 1 st procedure.22 needs auxiliary procedure like five patients need 2 nd look PCNL, six needs Ureoterorenoscopy (URS), & eleven11 needs Extracorporeal Shock Wave Lithotripsy (ESWL) and ultimate stone free result in 93%.

Table I :
Patient's characteristics
12scussionPCNL is established as the main modality for managing large renal calculi since Fernstrom and Johanson first used a nephrostomy tract to extract a stone in 197611.PCNL is presently the most demanding operative technique.The difficulty is solely related to obtaining access to the renal collecting system.PCNL is therefore recommended as the treatment of choice for renal stones measuring >15 mm in diameter12.PCNL has proved to be a less morbid procedure compared to open stone surgery.In the PCNL our target were to improvement of appropriate calyceal puncture, reduce operative time, remove the maximum bulk of the stone burden with the minimum number of punctures and reduce complications.After PCNL our stone-free rates 82% after 1 st procedure.22needsauxiliary and ultimate stone free result in 93%.Desai et al., Mishra et al., Winfield et al., de la Rosette et al.Conclusion: