Stesura Seveso Archivio Italiano di Urologia e Andrologia 2024; 96(4):12951 1 ORIGINAL PAPER tion (1). Postoperative pain control after IPP surgery can be enhanced by targeting nerve endings and receptors in penile tissues. The dorsal penile nerve, formed by converg- ing nerve fibers, carries signals through the pudendal nerve to the spinal cord (S2-S4), then to the thalamus and sen- sory cortex. Anesthesia can be applied at various points along this pathway, including the dorsal nerve, perineal nerve, pudendal nerve, and S2-S4 nerve roots (2). Several studies explored intraoperative analgesia for postoperative pain control. Raynor et al., for instance, found that the dor- sal penile nerve block (DPNB) reduced early postoperative pain but did not impact postoperative narcotic use (3). Additionally, Xie et al. studied the effectiveness of a combi- nation of penile dorsal nerve and ring blocks, while Hsu et al. investigated the efficacy of a crural block. Both studies noted a decrease in early postoperative pain, although rates of postoperative narcotic use were not reported (4, 5). The opioid fentanyl, possessing lipophilic properties, exhibits rapid onset and demonstrates up to 20 times greater potency when administered via the intrathecal route in comparison to the intravenous route (6). However, the use of intrathecal fentanyl has been linked to an increase in intravenous opioid requirement during the postoperative period, potentially attributable to sub- tle opioid tolerance or opioid-induced hyperalgesia (7). Additionally, it has been noted that intrathecal fentanyl doses exceeding 0.25 µg/kg may reach a "ceiling effect," indicating that higher doses do not enhance intraopera- tive analgesia and may amplify adverse effects (8). Our study compares intrathecal fentanyl and dorsal penile nerve block for controlling postoperative pain in patients undergoing insertion of an inflatable penile pros- thesis. PATIENTS AND METHODS A concurrent cohort study was conducted at the Urology and anesthesia Departments, Faculty of Medicine, Al-Azhar University, Cairo, Egypt. The study spanned from February 2022 to February 2024 and included 80 eligible patients Objectives: To compare the efficacy of intrathecal fentanyl and dorsal penile nerve block for postoperative pain management in patients undergoing inflatable penile prosthesis (IPP). Patients and methods: A prospective single-center study included 80 patients amenable to IPP. Patients were divided equally into two groups. Group I included 40 patients who were managed with spinal anesthesia with intrathecal fentanyl before undergo- ing IPP. Group II comprised 40 patients who received spinal anesthesia with dorsal penile block before IPP. Study groups were compared regarding postoperative VAS (Visual Analog Scale) scores, total narcotics consumption, patient satisfaction levels, and perioperative complications. Results: The study groups were comparable regarding baseline patients’ criteria. The operative time was comparable between the study groups, with group I and group II having respective median times of 64 minutes (interquartile range: 55-78) and 67 minutes (interquartile range: 56-81) (p = 0.65). Additionally, both groups demonstrated similar distributions in IPP implant cylinder and reservoir size (p = 0.9). Postoperative pain was higher in group I, with a statistically significant difference (p < 0.001). Eight patients in group I (20%) called the physi- cian’s office asking for pain medication, compared to two patients in group II (5%) (p = 0.04). 85% of patients in group II were highly satisfied compared to 50 % in group I (p = 0.003). We reported a 5% complication rate in group I compared to 2.5% in group II (p = 0.6). Conclusions: The present study found that the dorsal penile nerve block offers superior postoperative pain control and patient satisfaction compared to intrathecal fentanyl for patients undergoing inflatable penile prosthesis insertion. KEY WORDS: Penile prosthesis; Penile block; Intrathecal fentanyl; Postoperative pain. Submitted 21 August 2024; Accepted 31 August 2024 INTRODUCTION Inflatable penile prosthesis (IPP) represents a gold-standard surgical treatment for medically refractory erectile dysfunc- Comparative study between intrathecal fentanyl and dorsal penile nerve block for controlling postoperative pain after inflatable penile prosthesis implantation Adel Elatreisy 1, 2, Yasser Ahmed 1, Ahmed Elgarhy 3, Mohamed Hindawy 1, Tamer Abouelgreed 1, Ismail Ahmed 3, Abdalla Abdalla 3, Hany Ramadan 3, Mohamed Aboelsuod 3, Khaled Shrief 3, Ayman Mohamed 3, Wael Ibrahim 3, Saeed Abdelhameed 3, Mohammad Alghamdi 2, Mohammed Alzahrani 2, Hamada Youssof 4 1 Urology Department, Faculty of Medicine, Al-Azhar University, Cairo, Egypt; 2 Urology Department, King Fahd Armed Forces Hospital, Jeddah, Saudi Arabia; 3 Anesthesia Department, Faculty of Medicine, Al-Azhar University, Cairo, Egypt; 4 Urology Department, Faculty of Medicine, Fayoum University, Fayoum, Egypt. DOI: 10.4081/aiua.2024.12951 Summary Archivio Italiano di Urologia e Andrologia 2024; 96(4):12951 A. Elatreisy, Y. Ahmed, A. Elgarhy, et al. 2 for elective inflatable penile prosthesis implantation with ASA I, II, and III at the facility. The study protocol received approval from the institutional review board. Informed written consent was obtained from all participants in com- pliance with ethical guidelines and regulations to ensure patient safety and confidentiality. Inclusion criteria IPP was considered for patients with ED after the failure of conservative therapy, including phosphodiesterase inhibitors, alprostadil urethral suppositories, vacuum erection devices, and intracavernosal injections. Exclusion criteria Patients with ASA IV and coagulopathy were excluded from the study. The study cohort was divided into two equally sized groups. The patients were prospectively allocated to treat- ment groups without randomization. The choice between intrathecal fentanyl or DPNB was made through mutual agreement by the patients and physicians. Group I con- sisted of 40 patients who underwent spinal anesthesia with intrathecal fentanyl before undergoing IPP. In com- parison, Group II comprised 40 patients who received spinal anesthesia with DPNB before IPP. Anesthesia technique Upon establishing an Intravenous (IV) line, a pre-load of normal saline was administered before the initiation of spinal anesthesia. Cardiorespiratory monitoring, includ- ing heart rate (HR), peripheral oxygen saturation (SPO2), and blood pressure (BP), was commenced for all patients. In the case of group, I, spinal anesthesia was induced using a 25-gauge BD Quinck spinal needle following the sterilization of the back and identification of the anatom- ical landmark. The needle was then inserted using a para- median approach at the L3-4 intervertebral lumbar space level. Upon successful confirmation of cerebrospinal fluid (CSF) flow, a combination of 15 mg (3 ml) of heavy bupi- vacaine and 0.25 mcg/kg (0.5 ml) of Fentanyl was intrathecally injected. For group II, spinal anesthesia induction involved the use of 3.5 ml (3 ml heavy bupivacaine plus 0.5 ml water for injection), followed by a dorsal penile nerve block per- formed by inserting an 18-gauge needle connected to a 20 CC syringe between the suspensory ligament and the base of the penis. A total volume of 20 bupivacaine was injected at the 2- and 10-o'clock positions (10 ml for each side) for the right and left dorsal penile nerves. All penile implant procedures were conducted by a single surgeon using a penoscrotal approach, employing Coloplast titan and Rigicon prostheses. Postoperative pain assessment was conducted using a visual analog scale (VAS) after the IPP surgeries at 2, 4, 8, 12, 16, 20, 24 and 36 hours. Patient satisfaction was eval- uated using the 5-point Likert scale, ranging from dissat- isfied (1) to completely satisfied (5). Outcome In the comparative analysis of the study groups, the param- eters considered encompassed patients' demographics, postoperative Visual Analog Scale (VAS) scores, total nar- cotics consumption, patient satisfaction levels regarding postoperative pain management, and perioperative compli- cations according to Modified Clavien Classification System (MCCS) (9). Statistical analysis We analyzed the data using the Statistical Package for Social Science (SPSS) software, version 29 (SPSS Inc., Chicago data. The descriptive statistics included percent- ages, frequencies, means, and medians. We compared categorical variables between the two groups using the Fisher exact test. Additionally, for normally and abnor- mally distributed continuous variables, we used the Student’s t-test or the Mann-Whitney U test, respectively. Statistical significance was defined as a two-tailed p-value of less than 0.05. RESULTS Group I included 40 patients who underwent spinal anesthesia with intrathecal fentanyl before undergoing IPP, while Group II included 40 patients who received spinal anesthesia with dorsal penile block before IPP. The study groups were comparable regarding baseline patients’ criteria, as depicted in Table 1. The smoking sta- tus and prevalence of prior prostatectomy, pelvic radia- tion therapy, Peyronie’s disease, diabetes, and hyperten- sion were similar across the study groups (p = 0.87). The operative time was comparable between the study groups, with group I and group II having respective median times of 64 minutes (interquartile range: 55-78) and 67 minutes (interquartile range: 56-81); the between-group difference was not statistically significant (p = 0.65). Additionally, both groups demonstrated sim- ilar distributions in implant cylinder size and reservoir size (p = 0.9), as shown in Table 1. As measured with the VAS score, post-operative pain was higher in group I, with a statistically significant difference Table 1. Comparison between the study groups regarding baseline patients’ criteria. Parameter Group I Group II P-value (n = 40) (n = 40) Age, median (IQR) 59 (51-72) 59 (52-70) 0.72 BMI, median (IQR) 29 (24-32) 29 (23-33) 0.62 Etiology/comorbidities, N (%) 0.87 DM 33 (82.5%) 35 (87.5%) HTN 21 (52.5%) 20 (50%) Smoking 18 (45%) 19 (47.5%) Peyronie’s disease 6 (15%) 5 (12.5%) Prostatectomy 1 (2.5%) 1 (2.5%) Radiotherapy 1 (2.5%) 0 Implant Cylinder size (cm), N (%) 0.93 < 18 4 (10%) 5 (12.5%) 18-19 13 (32.5%) 11 (27.5%) 20-21 15 (37.5%) 17 (42.5%) ≥ 22 8 (20%) 7 (17.5%) Reservoir Size ≥ 100cc 13 14 0.91 Operative time (minutes), median (IQR) 61 (45-80) 63 (45-76) 0.65 Archivio Italiano di Urologia e Andrologia 2024; 96(4):12951 3 Comparative study between intrathecal fentanyl and dorsal penile nerve block... (p < 0.001), as shown in Table 2. Eight patients in group I (20%) called the physician’s office asking for pain med- ication, compared to two patients in group II (5%) with a statistically significant difference (p = 0.04). Regarding patients’ satisfaction with post-surgery pain control, 85% of patients in group II were highly satisfied compared to 50 % in group I. On the other hand, 25% of group I reported low satisfaction on the 5-point Likert scale compared to 5% in group II, with a significant p-value (p = 0.003) (Table 2). The 90-day perioperative complication rates were com- parable between the study groups, as shown in Table 2. We reported a 5% complication rate in group I compared to 2.5% in group II (p = 0.6). DISCUSSION Pain control after IPP surgery has been well studied and includes a multimodal analgesic approach that utilizes combinations of different non-opioid analgesics (10). Given the significant impact of the opioid epidemic, there is a growing emphasis on reducing narcotic use in post- operative care. Consequently, nerve blocks are increas- ingly employed in urological procedures as an essential strategy for achieving this goal (11). There are multiple studies about the intra-operative use of local anesthesia to improve pain control during penile prosthesis surgery. Nagao and colleagues studied the uti- lization of dorsal penile nerve block with 10 mL of bupi- vacaine as a single pain control approach during non- inflatable prosthesis insertion in 20 patients at a mean fol- low-up of 3.4 years; they did not report any patient with chronic penile pain (12). Ghanem and Fouad reported a series of 159 patients who received a dorsal penile nerve block for anesthesia during implantation of a penile prosthesis; additional general anesthesia was reported in 1.8%, and 5% of their cohort required additional local anesthesia (13). However, they did not report postoperative pain control. Raynor and colleagues investigated the efficacy of dorsal penile block in pain control compared to placebo after 30 penile prosthesis implants; they found that VAS scores were significantly lower in patients with penile block (14). In their study, Gürkan and colleagues compared an ultra- sound-guided penile nerve block administered to patients undergoing implantation under spinal anesthesia and a control group who did not receive local anesthesia. The results indicated that patients who received the penile nerve block exhibited lower VAS scores and reduced opi- oid consumption during all observed time intervals up to 24 hours (15). Numerous studies have indicated that the use of intrathe- cal fentanyl in combination with bupivacaine results in reduced requirements for intraoperative supplemental analgesia, a decreased incidence of intraoperative nau- sea/vomiting, and an extended duration until the first analgesic request (30). The aggregated data from 14 studies revealed an 8% inci- dence of pruritus in patients administered intrathecal fen- tanyl, in contrast to 0.6% in the placebo cohort (30). In the present study, we conducted a comparative analy- sis of the effectiveness of dorsal penile block and intrathe- cal fentanyl in managing postoperative pain among patients undergoing inflatable penile prosthesis insertion. Our findings indicate that DPNB demonstrated superior efficacy in pain reduction, accompanied by a significant decrease in postoperative narcotic usage and greater over- all patient satisfaction. There were no adverse events with intrathecal fentanyl, and the incidence of perioperative morbidities was comparable to DPNB. Limitations of the study The current study introduces a novel prospective com- parison between dorsal penile block and intrathecal fen- tanyl. However, it is essential to note that the study has certain limitations, such as the absence of randomization and a relatively small sample size. CONCLUSIONS Our research illustrates that the dorsal penile block offers superior postoperative pain management and patient sat- isfaction compared to intrathecal fentanyl for patients undergoing inflatable penile prosthesis insertion. Ethical approval All procedures conducted in this study complied with the Institution and National Research Committee's ethical standards, the 1964 Declaration of Helsinki, and its sub- sequent amendments or equivalent ethical standards. The institutional review board approved the protocol for the current study of the Anesthesia Department at the Faculty of Medicine, Al-Azhar University Hospital. Informed written consent was obtained from all partici- pating patients. Table 2. Comparison between the study groups regarding postoperative outcomes. Parameter Group I Group II P-value (n = 40) (n = 40) VAS score, mean ± SD 2 hours 1.8 ± 0.52 1.73 ± 0.59 0.55 4 hours 3.7 ± 0.76 1.85 ± 0.62 < 0.001 8 hours 4 ± 0.72 3 ± 0.64 < 0.001 12 hours 5.3 ± 1.6 3.6 ± 1 < 0.001 16 hours 6.2 ± 1.8 2.8 ± 1 < 0.001 20 hours 7.5 ± 1 3.9 ± 0.6 < 0.001 24 hours 7.5 ± 0.9 4 ± 0.7 < 0.001 36 hours 6.4 ± 1 3.8 ± 0.5 < 0.001 Post operative calls for pain meds, N (%) 8 (20%) 2 (5%) 0.04 Hospital stay in hours, median (IQR) 35 (34-39) 35 (33-38) 0.82 Patients satisfaction with 5-point Likert scale, N (%) 0.003 Low satisfaction (1-2) 10 (25%) 2 (5%) Intermediate satisfaction (3) 10 (25%) 4 (10%) High satisfaction 20 (50%) 34 (85%) 90-days complications according to MCCS, N (%) 0.6 Total 2 (5%) 1 (2.5%) Wound seroma (IIIb) 1 (2.5%) 0 Device Infection (IIIb) 1 (2.5%) 1 (2.5%) MCCS: Modified Clavien Classification System. Archivio Italiano di Urologia e Andrologia 2024; 96(4):12951 A. Elatreisy, Y. Ahmed, A. Elgarhy, et al. 4 REFERENCES 1. 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Correspondence Adel Elatreisy, MD, MSc, PhD (Urol), FRCS (Urol) (Corresponding Author) dr_adelelatreisy@yahoo.com Adel.elatreisy@azhar.edu.eg Urology Department, Faculty of Medicine, Al-Azhar University, Cairo, Egypt Urology Department, King Fahd Armed Forces Hospital, Jeddah, Saudi Arabia Flat 1, 3245 Manazil Aleuzama’ Street, Ar Ruwais Dist, Jeddah, Saudi Arabia Postal code: 23211 Yasser Ahmed dryasserbadran@gmail.com Mohamed Hindawy hindawy78@gmail.com Tamer Abouelgreed dr_tamer_ali@yahoo.com Urology Department, Faculty of Medicine, Al-Azhar University, Cairo, Egypt Ahmed Elgarhy elgarhy_79@yahoo.com Ismail Ahmed ismailabdelgawad.623@azhar.edu.eg Abdalla Abdalla abdalla201@yahoo.com Hany Ramadan hanysaid.icu@gmail.com Mohamed Aboelsuod abosoad.mohamed2017@gmail.com Khaled Shrief khaledshrief2@gmail.com Ayman Mohamed ayman_icu@yahoo.com Wael Ibrahim waelelmahdy@gmail.com Saeed Abdelhameed dr_said_mostafaa@yahoo.com dr_said_mostafaa@yahoo.com Anesthesia Department, Faculty of Medicine, Al-Azhar University, Cairo, Egypt Mohammad Alghamdi mmss.19903@hotmail.com Mohammed Alzahrani mohdsaleh9@hotmail.com Urology Department, King Fahd Armed Forces Hospital, Jeddah, Saudi Arabia Hamada Youssof hay02@fayoum.edu.eg Urology Department, Faculty of Medicine, Fayoum University, Fayoum, Egypt Conflict of interest: The authors declare no potential conflict of interest.