Introduction: Obesity increases both the incidence of nephrolithiasis and the technical challenges of percutaneous nephrolithotomy (PCNL). Evidence comparing supine and prone PCNL in obese patients remains scarce, with only one prior study worldwide. We compared perioperative outcomes of the two positions in the largest Asian obesespecific cohort to date. Methods: We retrospectively reviewed all adults with body mass index > 30 kg/m2 who underwent unilateral PCNL at Sarawak General Hospital and Sarawak Heart Centre between May 2020 and April 2023. Patients who had bilateral PCNL or concomitant procedures were excluded. Pre-operative non-contrast CT defined stone burden and Guy Stone Score; operative variables, outcomes and complications were extracted from the records and analysed. Results: A total of 124 patients were analysed (supine n = 79; prone n = 45). Baseline age, sex, BMI and ASA classification were similar, but the prone group harboured larger stones (mean surface area 11.04 vs 5.68 cm2, p < 0.001) and more Guy stone score 4 cases. Mean operative time was significantly shorter in the supine position (96.9 ± 46.7 min) than in the prone position (159.6 ± 66.7 min; p < 0.001), the difference was most pronounced in Guy stone score 2 and 3 cases. This represents an approximate 63-minute operative time reduction with the supine approach. Stonefree rates (67.1% supine vs 68.9% prone; p = 0.837), overall treatment success (81% vs 73.3%; p = 0.319), transfusion (2.6% vs 8.9%; p = 0.113), complications (p = 0.134) and hospital stay (2.3 ± 1.6 vs 2.6 ± 1.9 days; p = 0.378) were similar. In Guy stone score 4 cases, the prone group showed a non-significant trend toward higher clearance. Conclusion: In obese patients, supine and prone PCNL provide equivalent safety and stoneclearance outcomes. Supine positioning offers a substantial operativetime advantage for low to moderate complexity stones, whereas the prone approach remains a viable option for very large or staghorn calculi when multiple tract access is anticipated.
References
[1]
Carron, M., Safaee Fakhr, B., Ieppariello, G. and Foletto, M. (2020) Perioperative Care of the Obese Patient. BritishJournalofSurgery, 107, e39-e55. https://doi.org/10.1002/bjs.11447
[2]
Chong, C.T., Lai, W.K., Zainuddin, A.A., Pardi, M., Mohd Sallehuddin, S. and Ganapathy, S.S. (2022) Prevalence of Obesity and Its Associated Factors among Malaysian Adults: Finding from the National Health and Morbidity Survey 2019. AsiaPacificJournalofPublicHealth, 34, 786-792. https://doi.org/10.1177/10105395221129113
[3]
Shavit, L., Ferraro, P.M., Johri, N., Robertson, W., Walsh, S.B., Moochhala, S., et al. (2014) Effect of Being Overweight on Urinary Metabolic Risk Factors for Kidney Stone Formation. NephrologyDialysisTransplantation, 30, 607-613. https://doi.org/10.1093/ndt/gfu350
[4]
Trinchieri, A., Croppi, E. and Montanari, E. (2016) Obesity and Urolithiasis: Evidence of Regional Influences. Urolithiasis, 45, 271-278. https://doi.org/10.1007/s00240-016-0908-3
[5]
Anwar, A., Uz Zaman, H., Haseeb, S.A., Ahmad, H., Awalrehman, and Khan, I. (2024) Association between Obesity and Risk of Kidney Stones: Exploring the Rule of Life Style Factors. InnovativeResearchinApplied, BiologicalandChemicalSciences, 2, 91-95. https://doi.org/10.62497/irabcs.2024.43
[6]
Crivelli, J.J., Redden, D.T., Johnson, R.D., Juarez, L.D., Maalouf, N.M., Hughes, A.E., et al. (2022) Associations of Obesity and Neighborhood Factors with Urinary Stone Parameters. AmericanJournalofPreventiveMedicine, 63, S93-S102. https://doi.org/10.1016/j.amepre.2022.01.033
[7]
Perumal, K.R., Chua, R.H.B., Teh, G.C. and Lei, C.C.M. (2022) Prevalence of Urolithiasis in Sarawak and Associated Risk Factors: An Ultrasonagraphy-Based Cross‐sectional Study. BJUICompass, 4, 74-80. https://doi.org/10.1002/bco2.152
[8]
Müller, M.J. (2013) From BMI to Functional Body Composition. EuropeanJournalofClinicalNutrition, 67, 1119-1121. https://doi.org/10.1038/ejcn.2013.174
[9]
Assimos, D., Krambeck, A., Miller, N.L., Monga, M., Murad, M.H., Nelson, C.P., et al. (2016) Surgical Management of Stones: American Urological Association/endourological Society Guideline, PART II. JournalofUrology, 196, 1161-1169. https://doi.org/10.1016/j.juro.2016.05.091
[10]
Türk, C., Petřík, A., Sarica, K., Seitz, C., Skolarikos, A., Straub, M., et al. (2016) EAU Guidelines on Interventional Treatment for Urolithiasis. EuropeanUrology, 69, 475-482. https://doi.org/10.1016/j.eururo.2015.07.041
[11]
Hassan, M., El-Nahas, A.R., Sheir, K.Z., El-Tabey, N.A., El-Assmy, A.M., Elshal, A.M., et al. (2015) Percutaneous Nephrolithotomy vs. Extracorporeal Shockwave Lithotripsy for Treating a 20-30 mm Single Renal Pelvic Stone. ArabJournalofUrology, 13, 212-216. https://doi.org/10.1016/j.aju.2015.04.002
[12]
Bryniarski, P., Paradysz, A., Zyczkowski, M., Kupilas, A., Nowakowski, K. and Bogacki, R. (2012) A Randomized Controlled Study to Analyze the Safety and Efficacy of Percutaneous Nephrolithotripsy and Retrograde Intrarenal Surgery in the Management of Renal Stones More than 2 cm in Diameter. JournalofEndourology, 26, 52-57. https://doi.org/10.1089/end.2011.0235
[13]
De, S., Autorino, R., Kim, F.J., Zargar, H., Laydner, H., Balsamo, R., et al. (2015) Percutaneous Nephrolithotomy versus Retrograde Intrarenal Surgery: A Systematic Review and Meta-Analysis. EuropeanUrology, 67, 125-137. https://doi.org/10.1016/j.eururo.2014.07.003
[14]
Zhou, X., Sun, X., Chen, X., Gong, X., Yang, Y., Chen, C., et al. (2017) Effect of Obesity on Outcomes of Percutaneous Nephrolithotomy in Renal Stone Management: A Systematic Review and Meta-Analysis. UrologiaInternationalis, 98, 382-390. https://doi.org/10.1159/000455162
[15]
Mak, D.K., Smith, Y., Buchholz, N. and El-Husseiny, T. (2016) What Is Better in Percutaneous Nephrolithotomy—Prone or Supine? A Systematic Review. ArabJournalofUrology, 14, 101-107. https://doi.org/10.1016/j.aju.2016.01.005
[16]
Li, J., Gao, L., Li, Q., Zhang, Y. and Jiang, Q. (2019) Supine versus Prone Position for Percutaneous Nephrolithotripsy: A Meta-Analysis of Randomized Controlled Trials. InternationalJournalofSurgery, 66, 62-71. https://doi.org/10.1016/j.ijsu.2019.04.016
[17]
Zhao, Z., Fan, J., Liu, Y., de la Rosette, J. and Zeng, G. (2017) Percutaneous Nephrolithotomy: Position, Position, Position! Urolithiasis, 46, 79-86. https://doi.org/10.1007/s00240-017-1019-5
[18]
Mazzucchi, E., Vicentini, F.C., Marchini, G.S., Danilovic, A., Brito, A.H. and Srougi, M. (2012) Percutaneous Nephrolithotomy in Obese Patients: Comparison between the Prone and Total Supine Position. JournalofEndourology, 26, 1437-1442. https://doi.org/10.1089/end.2012.0257
[19]
Thomas, K., Smith, N.C., Hegarty, N. and Glass, J.M. (2011) The Guy’s Stone Score—Grading the Complexity of Percutaneous Nephrolithotomy Procedures. Urology, 78, 277-281. https://doi.org/10.1016/j.urology.2010.12.026
[20]
de la Rosette, J.J.M.C.H., Zuazu, J.R., Tsakiris, P., Elsakka, A.M., Zudaire, J.J., Laguna, M.P., et al. (2008) Prognostic Factors and Percutaneous Nephrolithotomy Morbidity: A Multivariate Analysis of a Contemporary Series Using the Clavien Classification. JournalofUrology, 180, 2489-2493. https://doi.org/10.1016/j.juro.2008.08.025
