Hypothesis / aims of study
Acute urine retention (AUR) is a common postoperative complication in various surgeries. The incidence of AUR after inguinal herniorrhaphy was previously reported to range from 0.37% to 22.2%. AUR may require urethral catheterization which causes significant discomfort, as well as increases the risk of catheter-related infection, risk for urethral trauma, and healthcare costs. Our study sought to determine the incidence of AUR and identify the risk factors for AUR following either open or laparoscopic herniorrhaphy.
Study design, materials and methods
Data for 426 male patients from a single center including baseline characteristics, comorbidities, and operative information were collected and reviewed retrospectively from the period of March 2018 to February 2019. AUR was defined as voiding difficulty after the surgery requiring catheter for bladder decompression. Statistical analysis was conducted for patient’s characteristics, medical histories, anesthesia notes and postoperative notes to identify any risk factors that may lead to AUR. Variables tested against the dependent variable (AUR) were selected using chi-square tests for categorical variables and t tests for continuous variables. Risk factors for the development of urinary retention in patients undergoing inguinal hernia repairs were deemed significant at P <0 .05. Multivariate logistic regression analysis was performed to examine the independent risk factors for AUR following inguinal herniorrhaphy.
A total of 426 patients were initially identified. 15 patients were excluded due to unstable vital signs at initial presentation ( n=9 ), acceptance of local anesthesia (n=3), and other concurrent urolithiasis surgery ( n=3 ). Among 411 male patients who underwent inguinal repair (laparoscopic: 279; open: 132), 31 patients experienced AUR after the operation, which came to an incidence of 7.5%. Old age, acceptance of open herniorrhaphy, spinal anesthesia, history of diabetes mellitus (DM), benign prostate hyperplasia (BPH) and usage of postoperative analgesics injection were statistically significant (P < 0.05) upon univariate analyses. On multivariable analysis, only DM (OR = 2.64, 95% CI = 1.02-6.81, P = 0.045), BPH history (OR = 2.37, 95% CI = 1.02-5.48, P = 0.044), acceptance of spinal anesthesia (OR = 2.31, 95% CI = 1.05-5.09, P = 0.038), and postoperative analgesics injection use (OR = 3.66, 95% CI = 1.66-8.11, P = 0.001) were identified as independent risk factors for postoperative urine retention.
Interpretation of results
AUR occurs frequently after inguinal hernia repair and significantly causes patient discomfort and may delay patients discharge. Predicting those who will develop AUR after the inguinal hernia repair can remind health care teams in the timely management of this complication and to help in prevention of this complication. In our study, 31 patients experienced AUR following either open or laparoscopic herniorrhaphy retrospectively, with an incidence of 7.5%. Elderly patients are indeed at risk for developing AUR in most of the previous studies. However, old age failed to show significance on our multivariable analysis. We identified history of DM and BPH, acceptance of spinal anesthesia and postoperative analgesics injection use as four independent risk factors for AUR following inguinal hernia repair. The etiopathogenesis of AUR as an inconvenient and uncomfortable event in the natural history of BPH was well established before. Diabetic bladder dysfunction presents in a broad spectrum of clinical symptoms ranging from overactive bladder to impaired bladder contractility. Our study is the first study to show DM as an independent risk factor for developing AUR after inguinal hernia repair. Acceptance of spinal anesthesia and postoperative analgesic injection, mostly narcotic agents are known to increase patients’ risk for urinary retention by reducing parasympathetic bladder tone, detrusor tone, and causing detrusor-sphincter dysfunction.