Comparison of Scoring Systems in Predicting Success of Percutaneous Nephrolithotomy

Background: Scoring systems are useful to inform the patients about the success and complication rates of the operation prior the surgery. Aims: To determine the applicability of the popular scoring systems (Guy's, stone size, tract length, obstruction, number of involved calices, and essence/stone density and Clinical Research Office of the Endourological Society) by means of examining preoperative data of patients treated with percutaneous nephrolithotomy. Study Design: Cross sectional study. Methods: We retrospectively reviewed files of the patients who had undergone percutaneous nephrolithotomy in our center between 2011 and 2015. Excluded from the study were patients aged <18 years, and those who were not assessed preoperatively with computed tomography. Preoperative computed tomography images of all patients were assessed by a single observer, and patients were graded based on three scoring system. Demographic data were analyzed along with perioperative data (operation, fluoroscopy, length of hospital stay, changes in hematocrit values, location, and number of access sites, stone-free and complication rates). Results: A total of 298 patients who had been treated with 300 procedures were enrolled into the study. Mean age, stone burden, number of stones, and density were 48.1±12.9 years, 663.5±442.8 mm2, 1.8±1.1 and 888.3±273 HU respectively. Scores of the cases based on Guy's, stone size, tract length, obstruction, number of involved calices, and essence/stone density, and Clinical Research Office of the Endourological Society scoring system were calculated as 2, 7.6, and 222.1 points respectively. 81.6% of the patients were stone-free. Complications were detected in 30 (9.9%) patients. Based on receiver operating characteristic curve analysis a positive correlation was detected between success rate and scoring systems, i.e., Guy's (p=<0.001, r=-0.309), stone size, tract length, obstruction, number of involved calices, and essence/stone density (p=<0.001, r=-0.295), and Clinical Research Office of the Endourological Society (p=<0.001, r=0.426). The Clinical Research Office of the Endourological Society scoring system had the highest predictive value. The sensitivity rates rates for Guy's, Clinical Research Office of the Endourological Society and Stone scoring system were as 78.78%, 80% and 82.34% respectively. Conclusion: All of scoring systems predicted correctly the success of the percutaneous nephrolithotomy procedures. The Clinical Research Office of the Endourological Society scoring system had the highest predictive value.

Percutaneous nephrolithotomy for isolated calyceal stones: How important is the stone location?

OBJECTIVE: To evaluate the effect of percutaneous access site on the success and complication rates of isolated calyceal stones. MATERIAL AND METHODS: We retrospectively evaluated 2700 patients who underwent percutaneous nephrolithotomy (PNL) in our clinic between October 2002 and August 2014. We selected only the patients with isolated lower, middle or upper calyceal stones and we grouped the patients according to the location of their stones. Successful operation was defined as complete stone clearence or retention of stone fragments smaller than 4 mm which do not lead to infection, obstruction or pain requiring treatment. Intraoperative and postoperative complications were also recorded. RESULTS: Totally 360 patients underwent PNL for their isolated upper, middle and lower calyceal stones. Access sites for those patients were selected based on stone location. The stones were localized in the lower (n=304), middle (n=14), and upper (n=42) calices. There was no statistically significant difference between the groups with respect to operation and scopy times. Hemoglobin drop was seen more frequently in the upper calyceal access group, without any significant intergroup difference. Thoracic complications including hemothorax, pneumothorax and pleural effusion were more common in the upper calyceal access group (11.9%; p<0.001). Complete stone clerance was accomplished in 81.9%, 92.9% and 78.6% of the patients with lower, middle and upper calyceal stones respectively without any significant intergroup difference (p=0.537). CONCLUSION: PNL is an effective and safe treatment modality for isolated calyceal kidney stones and upper calyceal access causes thoracic complications more than other access sites.

A comparative study of percutaneous nephrolithotomy in supine position and endoscopic combined intrarenal surgery with flexible instrument.

OBJECTIVE: To compare the results obtained in percutaneous nephrolithotomy after introduction of flexible ureteroscopy/nephroscopy (endoscopic combined intrarenal surgery - ECIRS) with nephrolitomies with only rigid nephroscopy (standard percutaneous nephrolithotomy; sPCNL). MATERIAL AND METHOD: A retrospective study of 171 sPCNL in Galdakao position performed between January 2005 and December 2011 was conducted. We compared the results obtained in those procedures in which endoscopic combined intrarenal surgery (ECIRS) was performed with those in which only the rigid nephroscopy (sPCNL) was used. Specific and global success, percentage of lithiasic load eliminated, days of hospital stay and complications derived were calculated. We defined success by complete absence of lithiasis or residual presence of<5mm. We differentiated specific success, that only achieved with percutaneous surgery, from global success, or that achieved after a second line of treatment. RESULTS: In 73 procedures (42.4%) ECIRS was performed with flexible endoscopy while in 98 (57.6%) it was done with sPCNL. Both groups were comparable in regards to demographic parameters and characteristics of the lithiasis. The success rates in the first procedure and global success were superior for the ECIRS group (75.3% vs 40.8% and 93.1% vs 74.5%), the differences being statistically significant (P<.05). No statistically significant differences were found in regards to the complications (28.8% vs 28.3% P=.86) or days of hospital stay (4.5 vs 5.0 P=.18). CONCLUSIONS: Use of the flexible ureteroscopy/nephroscopy in sPCNL (ECIRS) improves the success rates and elimination of lithiasic load, making it possible to perform the surgery with a single access in most of the cases.

Analysis of the factors affecting blood loss in percutaneous nephrolithotomy: a registry of the Spanish Association of Urology in the supine position.

OBJECTIVE: Percutaneous nephrolithotomy (PCNL) is the minimally invasive procedure of choice for removing renal stones larger than 2 cm. This study has aimed to identify the different variables that might influence decrease of hemoglobin during the surgery performed in supine position. MATERIAL AND METHODS: A prospective, multicenter, observational study of supine PCNL, based on the Spanish Association of Urology database, was analyzed. The different preoperative and postoperative factors that might affect the decrease of hemoglobin were assessed: demographics and anthropometric data, comorbidities, size and location of the stones, anatomical variants and technical aspects of the procedure. RESULTS: From September 2008 to December 2012, 397 supine PCNL procedures performed in 15 Spanish centers were registered. Mean hemoglobin decrease was 2.3±1.5 g/dl and overall blood transfusion rate was 5.5%. No statistically significant differences were found between genders, body mass index (BMI) and age in terms of blood loss. There were also no differences between patients with cardiovascular, hypertensive, diabetic and anticoagulant treatment background. Blood loss was not significantly influenced by stone size and location. Technical aspects of the procedure as operative time (> 120 min ≤), access to the pelvi-caliceal system (ultrasound, fluoroscopy), percutaneous tract dilation technique (Alken, balloon or Amplatz) or placement of nephrostomy (tube versus tubeless) were not associated with differences in pre-op/post-op hemoglobin. Only multiple percutaneous tracts (≥2) and middle calix access were statistically significantly (P=.03 and P=.01) related with less blood loss. CONCLUSIONS: PCNL in supine position is a minimally invasive procedure for removal of large (≥2 cm) and multiple renal stones, with a low incidence of blood loss and minimal transfusion rate. Multiple percutaneous tracts and middle calix puncture were the only statistically significant variables associated with decrease in hemoglobin levels.

The comparison of standard and tubeless percutaneous nephrolithotomy procedures

To compare totally tubeless and standard percutaneous nephrolitotomy procedures on many parameters.

Percutaneous nephrolitotomy was performed on 195 patients between June 2009 and May 2012. The data of those patients were evaluated retrospectively. Totally tubeless cases were enrolled to Group 1, and Group 2 consisted of non-tubeless cases (re-entry or Foley catheter).

Group 1 included 85 cases and group 2 a total of 110 patients. Paper tracing values for the kidney stones were 321.25 ± 102.4 mm2 and 324.10 ± 169.5 mm2 respectively. Mean fluoroscopy time was 4.9 ± 1.9 min and 5.08 ± 2.7 min, mean operation time was 78.8 ± 27.9 min and 81.9 ± 28.77 min and mean decrease in hematocrit was 2.6 ± 1.6 and 3.74 ± 1.9 respectively. All these comparisons were statistically significant. Length of hospitalization was 1.6 ± 1.1 and 3.5 ± 1.5 days for Groups 1 and 2 respectively. Mean superficial pain score was 5.8 ± 1.6 and 6.7 ± 1.2 respectively for both groups after 1 hour. At 6 hours, the scores changed to 3.87 ± 1.22 and 4.84 ± 1.3 respectively. The analgesic dose was 1.00 ± 0.7 and 1.53 ± 0.6 for the groups respectively at 6 hours. All the statistical differences were significant for these three parameters.

We believe that, because of their post operative patient comfort and decreased length of hospital stay, totally tubeless procedures should be considered as an alternative to standard percutaneous nephrolitotomy. .

Nefrolitotomía percutánea en pacientes con cirugía bariátrica: ¿mayor riesgo de complicación? / Percutaneous nephrolitotomy in bariatric surgery patients. Is there an increased risk of complications

Introduction: To report a patient with a history of bariatric surgery and staghorn calculi of the left kidney, who had a colonic perforation after percutaneous renal surgery. Material and Methods: A 38 years old male patient, with a history of gastric bypass, underwent a left percutaneous nephrolithotomy due to staghorn renal calculi. In the procedure, the colon was incidentally perforated during the percutaneous access. Results: The patient developed a sepsis and fecal material appeared surrounding the nephrostomy tube. A transverse colostomy was performed, with improvement of the sepsis and a spontaneous resolution of the nephro-colonic fistula. Conclusion: Is known that bariatric surgery is associated with the novo urinary lithiasis. Besides, there are anatomical changes in between intraabdominal viscera. Radiological studies and a adequate surgical strategy are fundamental to avoid severe surgical complications in kidney stone disease.

Objetivo: Presentar el caso de un paciente con antecedente de cirugía bariátrica y litiasis renal coraliforme, el cual presentó una perforación colónica luego de una nefrolitectomía percutánea. Material y Métodos: Paciente hombre de 38 años de edad con antecedente de bypass gástrico. Fue sometido a una nefrolitectomía percutánea por litiasis renal izquierda coraliforme, complicada de una perforación colónica no reconocida en forma precoz. Resultados: El paciente evolucionó con cuadro séptico y presencia de material fecaloídeo en la zona de la nefrostomía, por lo que requirió colostomía transversa, con resolución de la complicación séptica y resolución de la fístula nefrocólica. Conclusión: Es sabido que la cirugía bariátrica se asocia a litogénesis urinaria y cambios anatómicos de las relaciones de los órganos abdominales. El estudio radiológico y la adecuada estrategia quirúrgica evitará complicaciones graves en la cirugía de la litiasis renal.