Lower urinary system symptoms (LUTS) and benign prostatic obstruction (BPO), which is one of its most important causes, are problems that are very common in men and significantly affect their quality of life [1]. The frequencies of these problems constantly increase with age, and they become more distressing and resistant to treatment [2]. In addition to voiding symptoms, it is known that the incidence of storage symptoms such as urgency, frequency, and nocturia is constantly increasing, and these should be routinely screened and treated [3]. The co-occurrence of voiding and storage symptoms is higher than the occurrence of voiding symptoms alone, and in general, the incidence of storage symptoms in elderly patients exceeds 70% [4]. For this reason, in elderly patients, there is a need for not only removing the obstruction but also developing new treatment approaches for persistent storage symptoms.

In BPO and associated LUTS cases, the first approach involves lifestyle changes and medical treatments, and the most frequently used medical agents towards storage symptoms in this patient group are anticholinergics [5]. Nevertheless, studies have usually reported that anticholinergics and mirabegron fall short in treatments that address BPO-associated storage symptoms [6]. In BPO/LUTS cases that are resistant to medical treatment, more noticeable improvements are seen in storage symptoms after surgical treatments such as the transurethral resection of the prostate (TURP) compared to medical treatment, and the priority in treatment is thus seen as the removal of the obstruction [7]. However, although the improvement in storage symptoms after the removal of the obstruction is more successful than that in medical treatments, the outcomes are still not considered adequate [8].

Transurethral bipolar radiofrequency (RF) thermotherapy is a minimally invasive method that does not require anesthesia and has been prominent in recent years. It is seen as an alternative to TURP, especially for patients who are older or have severe comorbidities [9]. In patients diagnosed with BPO who also have significant storage symptoms, this method is expected to not only allow the removal of the obstruction but also result in improvements in storage symptoms with the denervation it causes [10]. Nevertheless, it was seen that there are not many studies in the recent relevant literature on the examination of the effects of this method on storage symptoms in addition to the removal of the obstruction.

This study is one of the rare examples in the literature in which TURP and RF thermotherapy were compared in terms of storage symptoms. The aim of our study is to compare the results of TURP and RF thermotherapy at 3 months and 6 months in elderly patients requiring surgery for BPO and to discuss the results with the literature.

The results of patients who underwent TURP and RF thermotherapy between December 2019 and December 2022 were prospectively recorded and analyzed retrospectively. The results of the patients included in the study were recorded 3 months and 6 months after the procedure. Patients over the age of 65 who received at least 4 weeks of alpha blocker therapy for BPO and were scheduled for surgical treatment, accompanied by severe storage symptoms in addition to voiding symptoms, and who did not use any anticholinergic treatment for these complaints were included in the study. All surgical procedures were performed under the responsibility and supervision of the same surgeon. The patients’ maximum flow rates (Qmax), prostate volumes (PVs), postvoid residual volumes, International Prostate Symptom Scores (IPSS) and overactive bladder validated 8 scores (OAB-V8) were questioned. The preprocedural values were compared with the 3rd and 6th month values after the procedure.

Surgical treatment was recommended because Qmax values were lower than 15 mL/sec after medical treatment and patients with OAB-V8 scores higher than 11 and PVs between 30–80 mL were included in the study.

The RF thermotherapy procedure was performed with the Tempro Direx ablation system (Direx Medical Systems Ltd., Petah Tikva, Israel). A transurethral catheter with appropriate sensors for the procedure was placed on the patients. Then, mid-model gradient method bipolar RF thermotherapy was applied at 55°C for 1 hour (Fig. 1).

The OAB-V8 form is a question form that scores storage symptoms, including the urge to urinate, nocturia, urge incontinence, and voiding frequency, and their severity. In the study, the OAB-V8 form, which had Turkish linguistic and psychometric validations, was used. In validity and reliability studies, its cutoff value has been determined as 11. Its use as a screening test provides highly successful results.

Patients who had undergone BPO-related surgery, had radiotherapy to the pelvic region, did not have sterile urine and required urodynamic examination were not included in the study and were used as exclusion criteria.

IBM SPSS Statistics ver. 21.0 (IBM Co., Armonk, NY, USA). Kolmogorov-Smirnov test was used for normality analysis. Parametric test methods were used for normal distribution and nonparametric test methods were used for nonnormally distributed data. Normally distributed variables were presented as mean±standard deviation, and nonnormally distributed variables were presented as median (range). For statistical analysis, Mann-Whitney U-test and Wilcoxon-rank test were used as appropriate. The effect size in this study was measured using Cohen (2013) criteria. For the simplest within-group and between-group comparisons, the sample size required for the effect value determined for a statistical power of 0.90 at the α= 0.05 level was obtained using GPower 3.1 software. The statistical level of significance was accepted as α=0.05.

In our study, a total of 212 patients with BPO were treated. Of these patients, 106 were in the RF thermotherapy group and 106 were in the TURP group. The mean age of the patients was 73.2±6.3 (66–79) in patients who received RF thermotherapy and 71.4±7.2 (66–78) in patients who underwent TURP (P= 0.67). While the body mass index value was 25.7±6.2 (19.4–28.7) kg/m² in RF thermotherapy patients, it was found to be 24.8±5.4 (19.1–30.3) kg/m² in patients who underwent TURP (P=0.35). American Society of Anesthesiologists physical status classification grade calculated in both patient groups were similarly 3.0±1.0 (P=0.81).

While the preprocedural OAB-V8 score in the RF thermotherapy group was 25.85, this score decreased to 18.12 at the postprocedural 3rd month and 16.42 at the postprocedural 6th month, showing significant regressions both from the preprocedural measurements to the postprocedural 3rd-month measurements (P<0.001) and from the 3rd-month measurements to the 6th-month measurements (P<0.001). In TURP patients, while the OAB-V8 score was 23.26 before the procedure, it decreased significantly to 20.17 in the 3rd month after the procedure (P<0.001). In contrast to the case in the RF thermotherapy patients, there was no significant difference between the 3rd-month OAB-V8 score of 20.17 and the 6th-month score of 19.84 (P=0.328) (Fig. 2). While the rate of decrease in OAB-V8 scores was 30% in the 3rd month and 36% in the 6th month in the RF thermotherapy group, it was 13% in the 3rd month and 15% in the 6th month in the TURP group. As a result of the 6-month follow-up, which was the primary end point of the study, it was determined that RF thermotherapy was 2.35 more effective than TURP on OAB-V8 scores (P<0.001).

When the storage symptoms were compared within the RF thermotherapy group; in the postprocedural 3rd-month measurements, there were significant decreases in the frequent daytime urination complaints of the patients from 3.64 in the preprocedural measurements to 2.77 and in their complaints of uncomfortable urges to urinate from 3.42 to 2.38 (P<0.001). In the postprocedural 6th-month measurements, the scores of these 2 parameters reached 2.52 (P<0.001) and 2.17 (P=0.003), respectively, indicating significant decreases compared to the postprocedural 3rd-month measurements. In the postprocedural 3rd-month measurements, there was a significant decrease in the complaints of the patients regarding a sudden urge to urinate from 2.86 in the preprocedural measurements to 1.83 (P<0.001), while their postprocedural 6th-month score was found 1.81, but the difference between the 3rd-month and 6th-month measurements was not significant (P=0.724). The accidental loss of urine complaint scores of the patients fell from 2.65 in the preprocedural measurements to 1.83 in the postprocedural 3rd-month measurements (P=0.001) and 1.67 in the postprocedural 6th-month measurements, continued with significant regression compared to 3rd-month (P=0.013). In the postprocedural 3rd-month measurements in comparison to the preprocedural measurements, the nighttime urination complaint scores of the patients and their complaint scores regarding waking up at night to urinate decreased significantly from 3.44 to 2.34 (P<0.001) and from 3.14 to 2.49 (P=0.003), respectively. There was also a significant decrease from the postprocedural 3rd-month measurements to the 6th-month measurements in terms of the patients’ complaints of nighttime urination (P=0.001). The uncontrollable urge to urinate complaint scores of the patients regressed significantly from 3.26 in the preprocedural measurements to 2.21 in the postprocedural 3rd-month measurements (P<0.001), to 1.99 in the postprocedural 6th-month measurements compared to the 3rd-month measurements (P=0.001). There was a significant difference in the patients’ complaints of urine loss associated with a strong desire to urinate between the preprocedural measurements and the postprocedural 3rd-month measurements (p=0.002), but the difference between the postprocedural 3rd-month mean score of 1.80 and the 6th-month mean score of 1.65 was not statistically significant (P=0.100) (Table 1).

When the storage symptoms were compared within the TURP group; in the postprocedural 3rd-month measurements, there were significant decreases in the frequent daytime urination complaints of the patients from 3.22 in the preprocedural measurements to 2.82 (P<0.001) and in their complaints of uncomfortable urges to urinate from 3.15 to 2.77 (P<0.001). In the postprocedural 6th-month measurements, the values of these 2 parameters did not change significantly in comparison to the 3rd-month values (respectively, P=0.225 and P=0.083). Similarly, in the postprocedural 3rd-month measurements, there was a significant decrease in the complaints of the patients regarding a sudden urge to urinate from 2.93 in the preprocedural measurements to 2.62 (P<0.001), but the value found as 2.66 in the postprocedural 6th-month measurements was not significantly different compared to the 3rd-month measurements (P=0.437). At 3 months and 6 months after the TURP procedure, there was no significant difference in the accidental urine loss complaints of the patients compared to their preprocedural measurements (respectively, P=0.222 and P=0.847). From the preprocedural measurements to the postprocedural 3rd-month measurements, the patients’ complaints of nighttime urination, waking up at night to urinate, uncontrollable urges to urinate, and urine loss associated with a strong desire to urinate decreased significantly. From the postprocedural 3rd-month to 6th-month measurements, there was a significant decrease in only the complaints of the patients regarding an uncontrollable urge to urinate (P=0.009), while there was no significant difference in the other 3 parameters (P=0.058, P=0.847, and P=0.643) (Table 2).

In the RF thermotherapy patients, while the mean Qmax value before the procedure was calculated as 9.7±4.3 mL/sec, it was calculated as 15.6±3.5 mL/sec at 3 months after the procedure (P<0.001) and 14.3±4.2 mL/sec at 6 months after the procedure (P<0.001). In comparison to the preprocedural value, the Qmax values at both the 3rd and 6th months in the postprocedural period were significantly higher. The mean IPSS value of the RF thermotherapy patients that was calculated as 21.2±3.7 before the procedure was found as 13.4±4.1 at 3 months after the procedure (P=0.003) and 13.1±3.5 at 6 months after the procedure (P=0.001). The mean preprocedural, 3rd-month postprocedural, and 6th-month postprocedural PVs of the patients in the RF thermotherapy group were 58.8±24.6 cm³, 51.9±23.4 cm³, 48.3±21.5 cm³, respectively, and there was no statistically significant difference (Table 1). In the TURP group, while the mean Qmax value before the procedure was calculated as 8.2± 3.7 mL/sec, it was calculated as 19.4±5.1 mL/sec at 3 months after the procedure (P<0.001) and 17.9±5.6 mL/sec at 6 months after the procedure (P<0.001). The mean IPSS value of the TURP group that was calculated as 23.8±5.5 before the procedure was found as 14.9±4.2 at 3 months after the procedure (P=0.002) and 12.1±2.7 at 6 months after the procedure (P<0.001). The mean preprocedural, 3rd-month postprocedural, and 6th-month postprocedural PVs of the patients in the TURP patients were 62.9±22.1 cm³, 20.3±18.5 cm³ (P=0.019), and 20.1±16.2 cm³ (P=0.014) (Table 3).

In the study, the effects of RF thermotherapy and TURP on storage symptoms accompanying BPO were compared. In the RF thermotherapy group, the decrease rate in OAB-V8 scores was 30% at 3 months and 36% at 6 months, while in the TURP group it was 13% at 3 months and 15% at 6 months. As a result of the 6-month follow-up, which was the primary endpoint of the study, the effect of RF thermotherapy on OAB-V8 scores was found to be 17% higher at 3 months (P<0.001) and 21% higher at 6 months (P<0.001), due to the estimated more permanent effect. It was determined that RF thermotherapy was 2.35 times more effective than TURP on OAB-V8 scores (P< 0.001). When the effects on scores were compared between the 2 procedures, the difference in effect between preprocedure and 3 months was more significant in RF thermotherapy (P<0.001). Similarly, the difference between the 3rd and 6th months was significantly higher in the RF thermotherapy group (P=0.001) (Fig. 2).

Bladder outlet obstruction is the most common cause of storage symptoms in elderly men, followed by changes in the detrusor muscle [11]. The first changes that occur in the detrusor muscle as a response to obstruction are increased collagen synthesis with hypertrophy and mucosal hypertrophy [12]. With the continuation of this obstruction, these hypertrophic changes are followed by fibrosis and disorganization [13]. Similar changes are also observed in neural structures, and in addition to hyperplasia in the mucosal structure, hypertrophy in afferent and efferent nerves and acetylcholine hypersensitivity in muscarinic receptors develop [14]. Due to this disorganization in the tissue, new reflex spinal pathways are formed through C fibers, and significant changes occur in the distributions of purinergic and muscarinic receptors [15]. Because of these changes that occur not only in the muscle tissue but also in the neural structure, storage symptoms become permanent conditions that severely disrupt the life comfort of BPO patients [16]. Therefore, the removal of the obstruction alone does not show the desired effect on storage symptoms [17]. The most frequently preferred medical agents against storage symptoms in BPO patients are anticholinergics and mirabegron. On the other hand, it is known that anticholinergics do not create sufficient clinical response in this patient group [18]. Surgical treatments such as TURP produce more effective improvements in storage symptoms in BPO patients in comparison to anticholinergics, but their effects are still not at the desired level [19]. For these reasons, patients who did not receive medical treatment before the procedure were included in our study to evaluate the procedure results more objectively. Patients were observed for 6 months due to potential changes in urothelial tissue after removal of the obstruction.

RF thermotherapy shows its effect on the prostate tissue by creating rapid vascular thrombosis and coagulative necrosis [20]. Due to the heat generated during the procedure, in addition to coagulative necrosis, this method also leads to denervation and axon loss in the neural tissue [21] (Fig. 3). The protein denaturation and angiopathy induced during the procedure becomes irreversible, especially at temperatures higher than 48°C, and it is known that this damage is more severe in the neural tissue compared to the smooth muscles [22]. Therefore, as opposed to the case in the TURP group, there were significant improvements in the Qmax values of the RF thermotherapy group without significant change in PVs. Due to these effects of RF thermotherapy, significant increases were observed in patients’ Qmax values, although there was no significant difference in PV.

When the 3rd month results of both methods were examined, significant improvements were found in OAB-V8 scores. In TURP patients, no significant change was observed in accidental urine loss at 3 months (P=0.222). As a result of the 3rd month evaluations after the procedure, it was determined that RF thermotherapy was more advantageous than TURP in preventing storage symptoms (P=0.11). The main difference between the 2 procedures was in their effects on storage symptoms in the postprocedural 6th-month measurements. The significant improvement in the OAB-V8 scores of the RF thermotherapy group was maintained not only from the preprocedural values to the postprocedural 3rd-month values but also from the postprocedural 3rd-month to the 6th-month values (P<0.001). However, it was observed that the improvement in the 3rd month did not continue in the 6th month in TURP patients and it did not contribute to the storage symptoms as much as the RF thermotherapy (P=0.328). Significant increases were observed in the Qmax values after both procedures, and it was expected that the removal of the obstruction would be effective on storage symptoms. However, it is thought that the RF thermotherapy method was highly effective on storage symptoms due to its denervation effects on the prostatic loge, urethral tissue, and regions close to the trigone induced by the additional irreversible nerve damage it created [23]. Its induction of afferent and efferent neuron damage in addition to its effects on the muscle tissue can explain the difference between the 2 groups in the postprocedural 6th-month measurements. Therefore, although the RF thermotherapy procedure did not show a significant reduction in PVs or a higher increase in Qmax values in comparison to the TURP procedure, it was determined to show long-term and effective benefits regarding storage symptoms.

RF thermotherapy is a minimally invasive procedure that does not require anesthesia and can be performed under outpatient clinic conditions. Thus, it is shown as an alternative to pharmacological and surgical treatments in older patients [24]. In our study, in the RF thermotherapy group, 8 patients experienced pain in the infrapubic region during the procedure, while 19 patients experienced pain and discomfort caused by the probe inserted during the procedure. No life-threatening complications were observed in any patient. In the TURP group, endoscopic interventions were made to 2 patients due to persistent hematuria causing retention, 8 patients had complaints of clinically significant fever after the procedure, and 2 patients developed urethral stricture. It was seen that RF thermotherapy was a suitable procedure for the group of patients over the age of 65, and it was easily applicable [25].

The limitations of the study are that it is conducted by a single center and only 6-month follow-up results are presented. In order to reveal the effects of RF thermotherapy more objectively, there is a need for multicenter, prospective studies with expanded patient numbers, which are added to urodynamic and pathological studies.

In elderly patients diagnosed with BPO, storage symptoms are pathologies that disrupt the quality of life of these patients, and they should be questioned. Because of the increased prevalence and severity of these symptoms by age, minimally invasive techniques that are safe in terms of adverse effects are needed. RF thermotherapy had a significant effect on the Qmax value, it was more effective on storage symptoms than TURP, and its effect continued at 6 months after the procedure. With its minimal profile of adverse effects, RF thermotherapy treatment can be offered to BPO patients with storage symptoms as a suitable option.