Benign prostatic hyperplasia (BPH) is one of the most common medical conditions in older men. Prostate enlargement is observed in approximately 40% of men in their 50s, and about 70% in their 60s [1]. Up to 15%-25% of men aged 50-65 years suffer from Lower Urinary Tract Symptoms (LUTS), influencing their quality of life [2]. Treatment options include lifestyle modifications, medical therapies [3], and surgical intervention.

Transurethral resection of prostate (TURP) continues to be considered the gold standard surgical procedure for BPH [4]. In selected patients, TURP is the surgical treatment of choice when medical treatment modalities fail. This procedure, which consists of removal of prostate tissue via transurethral electrocautery, is considered highly effective, but involves absorption of irrigation fluid into the bloodstream during the procedure. Risk of complications such as bleeding, urinary tract infection, TURP syndrome and sepsis are present. Urinary tract infection (UTI) is the most common complication following TURP [5]. The rate of UTI after monopolar or bipolar TURP, ranges from 4.1-6.2% and 2.6-8.4%, respectively [6]. Osman et al., [7] reported some risk factors for persistent bacteriuria following TURP, including older age, previous history of diabetes mellitus (DM), large prostate size, positive preoperative bacterial urine culture, preoperative catheter use, previous urological interventions, large size of sheath, long duration of operation, postoperative catheter events, and postoperative manual wash. Furthermore, not all bacteriuria events following TURP present with fever, and therefore are under-reported. Herein we aimed to evaluate the risk factors predicting fever due to UTI after TURP surgery at our institution.

177 patients with a mean age of 71 ± 8.7 years underwent TURP during the study period. All patients received antibiotic prophylaxis prior to the procedure. 83 patients with negative urine culture were treated empirically with intravenous Amikacin + Ampicillin as per institutional policy. 94 patients with positive urine culture were treated based on their individual antibiotic sensitivity profiles. All procedures were completed without complications. 9/177 (5.1%) patients developed post-operative fever. 1/83 (1.2%) of the negative culture group developed fever, compared to 8/94 (8.5%) in the positive urine culture group (P = 0.0375). 58 patients had DM, of which 4 (6.9%) developed post-operative fever, compared to 5/119 (4.2%) in non-diabetic patients (P = 0.48). 59 patients had permanent urethral catheter prior to the procedure, of which 5 (8.5%) developed post-operative fever, compared to 2 (3.4%) in the remaining patients that were not on a permanent urethral catheter. 12 patients underwent additional cystolithotripsy, of which none developed post-operative fever (Table 2 and Fig. 1). Median prostate size was 44.5 ± 23.9 cm³ (range: 9-150 cm³).

Figure 1.

Percentage of post-operative fever cases when combining all risk factors groups.

Surprisingly, small prostate size increased the risk of fever; median prostate size was 25 cm³ in patients who developed fever (n = 9) compared to 46 cm³ in all other patients (P = 0.016) (Fig. 2). On multivariate logistic regression, smaller prostate size (RR = 1.06, CI-95%, 1.01-1.12,), positive urine culture (RR = 3.85, CI-95%, 1.33-100) and older age (RR = 1.1, CI-95%, 1.01-1.21) were all predictive factors of postoperative fever (P < 0.05).

Figure 2.

Preoperative Prostate size in cm³ measured by transabdominal ultrasound.

TURP is the most common surgical intervention for benign prostate enlargement. The procedure includes transurethral resection and removal of prostate tissue while irrigating with 5% glycine solution or saline. UTI is the most common post-operative complication [5]. Most, but not all UTI's, will present with post-operative fever. Patient-related and surgical procedure-related risk factors are well defined. Post-operative fever following TURP is associated with prolonged hospitalization, additional antibiotic treatment, and subsequently increases cost and morbidity [8]. Better characterization of patients at risk of post-operative fever may improve practice and management of these patients. In our current study, 5.1% of patients of the entire cohort developed fever during the first week after the TURP procedure. Remarkably, a similar outcome (6.1%) was reported by Wagenlehner et al., [9] who conducted a multicenter study in Germany with 376 patients; consistently, Schneidewind et al., who also undertook a large multicenter study with 400 patients in Germany, also reported a similar outcome of 4.9% of patients developing fever [10]. No patient developed sepsis. Pre-operative positive bacterial urine culture was identified as a risk factor for developing post-operative fever (8.5% vs. 1.2%, RR = 3.85 range 1.33-100, P < 0.05). DM, indwelling urethral catheter and TURP combined with cystolithotripsy were reported by Osman et al., [7] as independent risk factors for bacteriuria, but did not increase the risk for post-operative fever in our cohort. This was ostensibly due to the strict following of pre-operative antibiotic coverage in our practice, preventing bacteriuria from becoming bacteremia. Higher complication rates were also previously described for longer TURP procedures. Due to our concern regarding record bias in accessing length of procedure, based on operation room registration in our cohort, we used prostate size as an indirect way of accessing operative time. Osman et al., reported prostate size larger > 60 cm³ as a risk factor for UTI post-operatively [7]. In contrast, we found that smaller prostate size slightly increased the risk for post-operative fever with an RR of 1.06. We assumed that operation time was not associated with risk of UTI in our cohort, however, patients with a smaller prostate size had increased incidence of pre-operative urinary retention and were more likely to carry indwelling catheter prior to TURP, subsequently having more bacteriuria and fever. Nevertheless, no statistically significant correlation was observed between prostate size and indwelling catheter (P = 0.21) or positive urine culture (P = 0.25), probably due to the relatively small size of the cohort.

In our patient cohort, we faced a high rate of positive urine culture prior to TURP (53.1%) and positive urine culture among patients with indwelling catheter (92%). Our practice is to treat with prophylactic intravenous antibiotic on the same day of the surgery and not postpone the procedure when facing a pre-operative positive culture, since it is difficult to achieve sterile urine in patients with indwelling catheter. While this practice might not eliminate the risk of UTI, we found an acceptable rate of post-operative UTI (8.5%), without additional risk of uro-sepsis.

Previous studies suggested that DM is a risk factor for post-operative UTI [7,11]. Our current data showed that 6.9% of the diabetic patients developed fever, compared to 4.2% of the non-diabetic patients (P = 0.48). Most patients in our cohort were treated properly, as recorded by preoperative hemoglobin A1C blood level (data not shown), therefore eliminating this risk factor. None of the 12 patients who had cystolithotripsy with TURP developed post-operative fever, suggesting that our practice of preoperative antibiotic prophylaxis was sufficient and effective for this group of patients as well.

Our current study has several limitations; the present cohort included TURP conducted by several surgeons. Additionally, no post-operative urine culture samples were collected routinely regardless of fever workup, reducing our ability to diagnose bacteriuria. A relatively low number of fever events influences the ability to identify additional risk factors as well. However, our findings represent a real-life practice of preventing post TURP fever in a tertiary hospital. Despite several known risk factors, our data show that adhering to perioperative urine culture collection practice, proper antibiotic treatment, and noticing urinary obstruction prior to surgery, markedly reduces the risk of fever due to UTI and sepsis. Additional trials to establish the optimal pre- and peri-operative antibiotic therapy and preoperative indwelling catheter management to prevent post-operative bacteriuria are warranted.

Kamil Malshy - Protocol and project development, data collection and manuscript writing; Omri Nativ - Data analysis and manuscript edition; Omer Sade - Data collection; Tareq Aro - Data collection; Alexander Kastin - Procedure surgeon; Alexander Kravtsov - Procedure Surgeon; Gilad E. Amiel - Manuscript editing; Michael Mullerad - Manuscript editing, protocol Development; Azik Hoffman - Data analysis and manuscript editing.

We want to thank Mrs. Tatiana Mashiach [Department of Epidemiology, Rambam] for statistical assistance, Prof. Michal Paul [Director, Infectious Diseases Institute Rambam] for helpful comments.

The authors declare that they have no conflict of interest.