Factors affecting complications according to the modified Clavien classification in complete supine percutaneous nephrolithotomy

Abstract

Cite as: Can Urol Assoc J 2015;9(1-2):e83-92. http://dx.doi.org/10.5489/cuaj.2248 Published online February 9, 2015. AbstractIntroduction: An increase in percutaneous nephrolithotomy (PCNL) has been accompanied by an increase in complications. We identified the parameters affecting the severity of complications using the modified Clavien classification (MCC). Methods: From 2008 to 2013, 330 patients underwent complete supine PCNL using subcostal access, one-shot dilation, rigid nephroscopy, and pneumatic lithotripsy. We assessed the impact of the following factors on complication severity based on the MCC: age, gender, body mass index, hypertension, diabetes, previous stone surgery and extracorporeal shock wave lithotripsy, preoperative hemoglobin, renal dysfunction (creatinine >1.4 mg/dL), preoperative urinary tract infection, anatomic upper urinary tract abnormality (AUUTA), significant (moderate-severe) hydronephrosis, stonerelated parameters (opacity, number, burden, location, staghorn, complex stones), anesthesia type, kidney side, imaging and calyx for access, tract number, tubeless approach, operative time, postoperative hemoglobin, and hemoglobin drop and stone-free results. Results: The complication rate was 19.7% (MCC: 0=80.3%, I=6.4%, II=11.2%, ≥III=2.1%). On univariate analyses, only the following factors affected MCC: gender, preoperative hemoglobin, AUUTA, significant hydronephrosis, imaging for access, calyx for access, tract number, postoperative hemoglobin, hemoglobin drop and stone-free result. Renal dysfunction was accompanied by higher complications, yet the results were not statistically significant. Multivariate logistic regression analysis demonstrated renal dysfunction, absence of significant hydronephrosis, AUUTA, multiple tracts, lower postoperative hemoglobin, and higher postoperative hemoglobin drop as the significant parameters which affected MCC and predicted higher grades. The paper's limitations include a low number of cases in the higher Clavien grades and some subgroups of variables, and not applying some techniques due to surgeon preference. Interpretation: Many of the complete supine PCNL complications were in the lower Clavien grades and major complications were uncommon. Renal dysfunction, AUUTA, significant hydronephrosis, tract number, postoperative hemoglobin, and hemoglobin drop were the only factors affecting MCC. IntroductionPresently, percutaneous nephrolithotomy (PCNL) is preferred as a safe and effective way to remove large or multiple upper urinary tract calculi. [1][2][3][4][5][6][7] An increase in PCNL has been accompanied by variations in positions, techniques, and instruments, and these may have led to increased complications.1,2,4,5 Following PCNL, 79.5% of patients may experience an uncomplicated postoperative period, 5,8 although there are reports of an early complication rate of 50.8%. 4PCNL complications may occur during puncturing, access, or stone removal. 4 A standardized classification allow us to compare complications among different instruments, te...

Tubeless versus standard percutaneous nephrolithotomy in pediatric patients: a systematic review and meta-analysis

“…The difference was not significantly different, although this may be because of highly heterogeneity between the studies. Also, in adults, Falahatkar et al (17) showed renal dysfunction, upper urinary tract abnormality, significant hydronephrosis, multiple tracts, post-operative hemoglobin and hemoglobin drop predicted complications and as a consequence, the length of hospital stay. Some of these predicted complications were similar between the two groups.…”

Single lower calyceal percutaneous tract combined with flexible nephroscopy: A valuable treatment paradigm for staghorn stones

“…2 Nevertheless, lower calyceal access and single-tract accesses are associated with a lower complication rate and shorter hospital stay. 3,4 Thus, combining the safety of a single lower calyceal tract with high SFRs would be an optimal scenario. The aim of the present study is to evaluate the effectiveness and safety of single lower calyceal tract combined with flexible nephroscopy for the management of staghorn renal stones by PCNL.…”

Safety and efficacy of percutaneous nephrolithotomy in the Galdakao - Modified Supine Valdivia position: A prospective analysis

“…Positive preoperative urine culture or preexisting UTI were reported by several authors as a significant parameter predicting complications (8-10): according to other studies (11,12) we have not founded this correlation with complications. Few studies investigated the correlation between normal or impaired renal function and onset of complications with discordant results: Yaycioglu (13) reported no difference, while Sairam and Falahatkar (14,15) showed a significantly increased complication rates associated to chronic kidney disease. In our study, only four patients were affected by impaired renal function pre PCNL, and with a postoperative progress in line with other patients.…”

“…In the study leaded by Shin stone' s size and staghorn or complex stone had a significant influence only in minor complications, such as UTI or pain (20). Some studies (9,15), one of the most recent was published on February 2015 by Falahatkar et al (15) reported the PCNL complications according to the modified Clavien system (MCC), a scale that allows to classify complications basing on life-treating condition, interventions required, and disability. Nevertheless the MCC cannot predict, as said by the same authors, the occurrence of a specific complication and cannot reveal its reason.…”