1557Vol. 11 | No. 03 | May - June 2014 |U R O LO G Y J O U R N A L Department of Urology, Isfahan Urology and Renal Transplanta- tion Research Center, Alzahra Hospital, Isfahan University of Medical Sciences, Isfahan, Iran. Mohammadhatef Khorrami, Mazaher Hadi, Mehrdad Mohammadi Sichani, Kia Nourimahdavi, Mohammad Yazdani, Farshid Alizadeh, Mohammad-hosein Izadpanahi, Farhad Tadayyon Percutaneous Nephrolithotomy Success Rate and Complications in Patients with Previous Open Stone Surgery Corresponding Author: Mehrdad Mohammadi Sichani, MD Department of Urology, Isfahan Urology and Renal Transplanta- tion Research Center, Alzahra Hospital, Isfahan University of Medical Sciences, Isfahan, Iran Tel: +98 311 624 9031 Fax: +98 311 669 2174 E-mail: m_mohammadi@med. mui.ac.ir Received October 2012 Accepted April 2014 Purpose: To determine the effect of previous single or multiple open stone surgeries on percu- taneous nephrolithotomy (PCNL) results and complications. Materials and Methods: We reviewed medical records of 1422 patients who had been under- gone PCNL in our institute between 1998 and 2011 by the same surgeon. Patients were divided into 3 groups. The first group included patients with no history of previous ipsilateral open stone surgery (n = 711). Patients in second group had been undergone only one open stone sur- gery before PCNL (n = 405) and patients with more than one previous open stone surgery were placed in third group (n = 306). We compared operation duration, stone free rate (SFR), number of attempts to access the collecting system and intraoperative and postoperative complications between 3 groups. Results: There were no differences in sex, body mass index, stone burden and laterality between 3 groups. Operation time was significantly shorter in the first group (P = .000) while there was no statistically significant differences in operation duration between second and third groups (P > .973). The number of attempts to enter the collecting system was significantly lower in the first group in comparison to other two groups (P = .00). We didn’t find significant differences between 3 groups in hospital stay, SFR, intraoperative and postoperative complications. Conclusion: Our findings demonstrated that PCNL can be performed in patients with one or more open stone surgery history successfully without further complications. Keywords: kidney calculi; surgery; nephrostomy; percutaneous; treatment outcome; lithotrip- sy; retrospective studies. ENDOUROLOGY AND STONE DISEASE 1558 | INTRODUCTION Percutaneous Nephrolithotomy (PCNL) was de-scribed by Fernstrom and johannson in 1976.(1) Im-provements in PCNL technology and instruments after its invention have made it the most useful surgical treatment to large kidney stones.(2) Recently European Asso- ciation of Urology (EAU) has considered PCNL as the first surgical option for large, multiple or inferior calyx kidney stones.(3) Open stone surgery has been replaced by PCNL because of its cost effectiveness, lower morbidity, shorter operative time and lower post-operative complications.(4,5) Some patients with the history of open stone surgery need PCNL because of renal stone recurrences.(6,7) Open stone surgery cause scar tissue and anatomical modifications in kidney that may affect later PCNL. Some studies have re- ported that previous open stone surgery can increase PCNL failure rate(8) while others show that previous open stone surgery does not affect PCNL outcome.(9,10) The aim of our study is to compare PCNL efficiency and complications in patients with and without the history of open stone surgery. MATERIALS AND METHODS We reviewed records of all PCNL procedures (1422 pro- cedures) that had been performed in Alzahra hospital from 1998 till 2011 by the same surgeon. patients categorized into 3 groups based on previous open stone surgery. Group 1 in- cluded patients with no history of open renal stone surgery on the ipsilateral kidney (n = 711). Patients who had been undergone only one previous open stone surgery classified as second group (n = 405). The third group consisted of patients with more than one open surgical history (n = 306). Patients with body mass index (BMI) ≥ 30, patients with abnormal renal anatomy such as ectopic or horse shoe kidneys and a stone burden of more than 700 mm2 were excluded from the study. The renal functions tests, serum electrolytes, hemoglobin, hematocrit, coagulation tests and urine culture were assessed before and daily after operation in all patients. If urine culture was positive, appropriate antibiotic prescribed for at least 2 weeks before undergoing PCNL. Intravenous urography was our preferred imaging modality and computed tomography (CT) scan was performed in patients with history of open surgery. Patients with retrorenal colon in CT scan were can- didate for open stone surgery. One patient had incisional her- nia due to previous open renal surgery, so he excluded from the study because of the risk of intestine perforation during PCNL. After general anesthesia, a 5 or 6 French (F) ureteral catheter was inserted and fixed to a Foley catheter. Patients were then turned into a prone position with special care for the pressure points. The desired calyx was punctured under fluoroscopic guidance and a guide wire was inserted. Tract dilation was performed by serial metallic dilators. After Amplatz sheath insertion, nephroscopy was performed and stones were frag- mented by a pneumatic lithotripter (Litho Crack, Sp. Swiss- Germany) and removed. Normal saline was used for continu- ous irrigation. If there was a more than 2 cm residual stone that could not be accessed from the first tract, a second access was established. Residual stones of less than 2 cm in diame- ter were scheduled for extracorporeal shock wave lithotripsy (SWL). No SWL was performed during first few days after surgery. Foley and ureteral catheter were removed 24 h after operation. Nephrostomy tube was clamped 48 h after opera- tion and removed after 24 h if there was no urine leakage, pain or fever. Seven days after surgery plain radiography and abdominal ultrasonography or CT scan (for radiolucent stones) were performed to determine the residual stones. Then we com- pared them to modalities were done before surgery to evalu- ate the stone free rate (SFR). Patients’ age, sex, BMI, stone burden, laterality, operative duration, length of hospital stay, number of attempts before successful entry into collecting system, SFR and complica- tions rate were compared between three groups. Statistical analysis was performed with statistical package for the social science (SPSS Inc, Chicago, Illinois, USA) version 16.0 us- ing the Chi-square and ANOVA tests. A P value < .05 was considered as significant. RESULTS Table 1 illustrates patients’ demographic and renal stones characteristics. Patients’ mean age in group 3 was signifi- cantly higher (50.4 ± 14.5, P = .001) in comparison to other two groups. There were no statistically significant differenc- es in patients’ sex, mean BMI, stone laterality and mean stone Endourology And Stone Disease 1559Vol. 11 | No. 03 | May - June 2014 |U R O LO G Y J O U R N A L PCNL in Patients with Previous Open Surgery | Khorrami et al burden between 3 groups. All patients had pelvis stone; 80, 82 and 83% of patients had concurrent lower or middle cal- yceal stones in first, second and third groups respectively (P = .87). Upper calyceal stone were detected in 15% of group 1, 13% of group 2 and 14% of patients in group 3 (P = .9). Mean Stone burden was the same in all groups. It was 4.76 ± 1.39 mm in group 1, 4.92 ± 1.34 mm in group 2 and 4.83 ± 1.38 mm in group 3 (P = .301). Mean operation duration was 116 ± 24, 128 ± 14 and 128 ± 14 minutes in groups 1, 2 and 3, respectively (P = .00). The mean hospital stay between 3 groups was not statistically different (P = .962) (Table 2). We also didn’t observe any significant differences between three groups in SFR (P = .75). Mean number of attempts to access collecting system was significantly lower in the first group (1.5 ± 0.9 vs. 2.5 ± 0.5 and 2.3 ± 0.4 in groups 2 and 3 respectively) (P = .00). One hundred eighty three patients (12.8%) in group 1, 61 pa- tients (15%) in group 2 and 22 (16.1%) patients in group 3 required a second access tract for additional stone removal (P = .5). As listed in Table 3 there were no differences between 3 groups regarding intraoperative and postoperative complica- tions. Seventy one patients (5%) in group 1, 11 (5.4%) in group 2 and 8 (5.8%) in group 3 received blood transfusion during or after procedures (P = .7). Postoperative fever de- veloped in 170 patients (23.9%) in group 1, 91 (22.4%) in group 2 and 72 (23.5%) in group 3 (P = .9). Auxiliary procedures such a second look PCNL and SWL were performed in 9.7, 10.2 and 11% of patients in groups 1, 2 and 3, respectively (P = .9). Delayed hematuria (more than 14 days after surgery) was seen in 16 patients in group 1, 3 in group 2 and 1 in group 3. One of 16 patients in group 1 required arteriography and angioembolization of an arterio- venous fistula. All other cases were managed conservatively. Colon perforation was occurred in 2 patients (both in group 1) that managed conservatively. Table 1. Demographic and clinical characteristics of study groups. Variables No. (%) Mean (SD) P P** Male/Female Group 1 1052/370 (74) --- --- Group 2 150/55 (73) .669a Group 3 98/38 (72) Right/Left side Group 1 892/520 (62.7) --- --- Group 2 121/84 (59) .370a Group 3 87/49 (64) Age (years) Group 1‡# 42.5 ± 12.25 .000# Group 2‡* --- 45.7 ± 17.27 .000b .003* Group 3# * 50.4 ± 14.5 .003‡ Body mass index (kg/m2) Group 1 27.44 ± 2.5 --- Group 2 --- 27.50 ± 2.6 .88b Group 3 267.9 ± 1.7 Stone burden (cm) Group 1 4.76 ± 1.39 --- Group 2 --- 4.92 ± 1.34 .301b Group 3 4.83 ± 1.38 a: Chi-square test; b: One-way ANOVA test. ** P value between study groups. 1560 | DISCUSSION Our findings showed that previous open stone surgery doesn’t affect subsequent PCNL results and complications. Conversely some studies demonstrated that anatomical changes that happen after open stone surgery such as infun- dibulum stenosis, perinephric fibrosis, bowel displacement and incisional hernia may decrease PCNL success rate and increase its complications.(11,12) Same as our study a num- ber of studies showed that PCNL can perform successfully without higher risk of complications in patients with a his- tory pf open surgery history.(12-14) The number of patients in our study is not comparable to others. We reviewed PCNL records of 1422 patients which was extremely higher than sample size in similar studies. On the other hand we didn’t find any study which compared patients with single and mul- tiple stone surgery history with ones without such a history separately as we did. Based on our findings history of single or multiple ipsilateral open renal stone surgeries does not af- Table 2. Percutaneous nephrolithotomy results and complications in study groups. Variables No. (%) Mean (SD) CI 95% P P** Hospital stay (day) --- Group 1 3.93 ± 1.47 Group 2 3.90 ± 1.47 .962a Group 3 3.92 ± 1.45 Operation time (min) Group 1 # * 116 ± 24 114-117 .000# Group 2 #‡ --- 128 ± 14 126-130 .000a .000* Group 3 ‡* 128 ± 14 125-130 .973‡ Access attempts (n) Group 1 ‡# 2.5 ± 0.9 .00# Group 2 ‡* --- 1.5 ± 0.5 .00a .122* Group 3 # * 1.3 ± 0.4 .00‡ Transfusion rate, no. (%) Group 1 #‡ 71 (5) Group 2 ‡* 11(5.4 ) .7b --- Group 3 *# 8 (5.8) Auxiliary procedures, no. (%) --- --- Group 1 138 (9.7) Group 2 21 (10.2) Group 3 15 (11) .9 Fever, no. (%) Group 1 341 (24) --- --- --- Group 2 46 (22.5) .9b Group 3 31 (23.7) Secondary tract, no. (%) Group 1 183 (12.8) Group 2 61 (15.0) --- --- .5b --- Group 3 22 (16.1) Stone free rate (%) Group 1 90.60 ± 5.96 --- .75a Group 2 90.45 ± 5.92 --- Group 3 89.63 ± 5.91 a: One-way ANOVA test; b: Chi-square test. ** P value between groups. Endourology And Stone Disease 1561Vol. 11 | No. 03 | May - June 2014 |U R O LO G Y J O U R N A L fect PCNL success rate. The mean operation time in the present study was signifi- cantly higher in groups with single or multiple previous stone surgeries in compare to first group while there was not any difference between patients categorized in second and third group. Two other studies also have expressed that operative time is longer in patients with a history of open nephroli- thotomy.(12,13) Factors that may cause prolonged PCNL in patients after open surgery are difficulties in tract dilation in scarred collecting system and perinephric spaces, difficulties in stone fragments removal by grasping forceps and rigid ne- phroscopy in scarred kidneys and cautious fixation of kidney in the retroperitoneum. The rate of auxiliary procedures like second-look PCNL or SWL was the same in all groups. Some other studies have reported the same result.(7,10,13,14) Only two studies have reported different results about auxiliary procedures need. (12,15) Margel and colleagues compared PNCL efficiency and morbidity in patients with previous nephrolithotomy with primary patients.(12) Based on their findings secondary pro- cedures was higher in patients with nephrolithotomy history. Gupta and colleagues also found that relook PCNL is higher in patients with previous open surgery (18.2% vs. 7.8%).(15) The mean number of attempts to enter the collecting system was significantly lower in group 1. Similar to our results Margel found that access attempts is higher in patients with open surgery history.(12) We didn’t find any other study which had reported significant differences between two groups in access attempts. Probably this difference is because of dis- torted calyceal anatomy due to previous open surgeries and subsequent scarring. Same as other studies our study showed that there are no dif- ferences between primary patients and patients with open surgery history in SFR and hospitalization time.(7,10,14) We also didn’t find any differences in PCNL complications in- cluding fever and transfusion rate between three groups. In small group of patients, distortion of pyelocalyceal system due to previous surgery or recurrent stone formation may decrease stone free rate.(11,12) Performing intravenous urog- raphy or CT-urography may helpful to identify such circum- stances before operation. Although our findings have demonstrated that PCNL can be performed successfully in patients with one or more open stone surgery history without further complications, some important items should be considered. Each endourologist encounters some cases with difficult rod insertion and tract dilation. Sometimes balloon or one shot dilation must be re- placed by tract dilation with metallic dilators. It seems that per- inephric fibrosis has an essential role in such cases. Perinephric scar tissue formation depends on some factors including long standing calculus pyelonephritis, previous surgery complica- tions (prolonged urine leakage), previous surgery type (neph- rolithotomy, pyeloplasty, pyelolithotomy and etc) and severity of endogenous patients' reaction to operation. Urinary tract infection usually leads wide adhesion resulted from serious inflammatory reaction around renal parenchyma. It has been shown that tract dilation is especially difficult in patients with cystinuria. It may be related to parenchymal fibrosis in such patients.(16) It seems that in this conditions stone free rate and complications may be different. So it is so important to con- sider above mentioned situations before PCNL of previous op- erated kidneys and prepare yourselves to encounter such dif- ficult conditions. So it is so useful to review previous surgery files, search about post operation infections and urine leakage, determine previous surgery type and get sure about metallic dilators accessibility in operating room. A complete imaging evaluation is also necessary to collect more information about such challenging cases. Some authors prefer a supracostal approach(11) while a lower calyceal puncture preferred by others.(9) Scarring after open nephrolithotomy is usually subcostal so the best approach which helps to avoid colonic injury is supracostal.(17) A sur- geon should avoid scar tissue when select the access site, but scar tissue alone is not an indication for upper-pole access as advocated by Margel and associates.(12) The calyx that pro- vides access to maximum stone burden is chosen as a primary calyx of entry regardless of its relation to scar tissue or ribs. CONCLUSION Based on our findings it doesn’t seem that previous open sur- gical procedures affect PCNL efficiency. PCNL complica- tions are also the same in patients with or without the history of open stone surgery. CONFLICT OF INTEREST None declared. PCNL in Patients with Previous Open Surgery | Khorrami et al 1562 | REFERENCES 1. Fernström I, Johansson B. Percutaneous pyelolithotomy. A new ex- traction technique. Scand J Urol Nephrol. 1976;10:257-9. 2. Preminger GM, Assimos DG, Lingeman JE, Nakada SY, Pearle MS, Wolf JS. Chapter1: AUA guideline on management of stag- horn calculi: diagnosis and treatment recommendations. J Urol. 2005;173:1991-2000. 3. Turk C, Knoll T, Petrik A, et al. Guidelines on urolithiasis. Chapter 6.4: selection of procedure for active removal of kidney stones. Presented at: 26th European Association of Urology Congress; March18–22, 2011; Vienna, Austria. 4. Al-kohlany KM, Shokeir AA, Mosbah A, et al. A treatment of com- plete staghorn stones: a prospective randomized comparison of open surgery versus percutaneous nephrolithotomy. J Urol. 2005;173:469-73. 5. 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