Vol 15 No 03 May-June 2018 31 PEDIATRIC UROLOGY Pudendal Nerve Block Versus Penile Nerve Block in Children Undergoing Circumcision A Cigdem Tutuncu,1* Pinar Kendigelen,1 Gulruh Ashyyeralyeva,1 Fatiş Altıntas,1 Senol Emre,2 Rahsan Ozcan,2 Guner Kaya1 Purpose: Penile nerve block is the most popular nerve block for the circumcision in pediatric patients. This study aimed to compare the analgesic efficiency of penile nerve block and the pudendal nerve block on postoperative pain and additional analgesic requirements in children undergoing circumcision. Material and Methods: This prospective randomized double-blind study enrolled 85 children, aged 1 to10 years, undergoing circumcision. The patients were randomly divided into two groups either receiving dorsal penile block group (PNB-Group) or pudendal nerve block (PDB-Group). In the PNB-Group, 0.3 ml/kg 0.25 % bupivacaine was used; and, in the PDB-Group, 0.3 ml/kg bupivacaine was applied with nerve stimulator at a concentration of 0.25 %. In the postoperative period, the modified CHEOPS pain scale scoring and additional analgesic demand were evaluated at the 5th and 30th minutes and at the 1st and 2nd hours. The subsequent pain evaluations were made by the parents at home, at the postoperative 6th, 12th, 18th and 24th hours. Results: Seven patients were excluded from the study, and seventy eight patients were evaluated for analysis. Patients in PDB-Group had significantly lower postoperative pain intensity and lower mCHEOPS scores (3.83 ± 0.98) when compared to the PNB-Group (6.47 ± 0.91) (P < .01) at all measurement times and none of patients in PDB-Group had additional analgesic requirements up to 24 hours. Patients in the PNB-Group had significantly more analgesic requirements at all measurements times except at the 1st, 2nd, 24th hours. 3.8%, 30.8%, 46.2% and 59% of the patients in the PNB group needed additional analgesia respectively at 5th, 6th, 12th and 18th hours. Conclusion: Pudendal nerve block provided additional analgesic free period and had better analgesic efficiency compared to the penile nerve block lasting until 24 hours after operation. Keywords: analgesia; circumcision; nerve block; pain; pediatric. INTRODUCTION Circumcision is one of the most frequently per-formed penile surgeries, necessitated by cultural, religious and medical reasons. Although a minor same day surgery, circumcision is painful with postoperative pain being one of the significant problems. Topically or intravenously administered agents and caudal or penile nerve blocks constitute the routine modes of analgesia used. The analgesic method employed has to be relia- ble, effective and compatible with fast recovery and low incidence of complication in patients sent home shortly after the intervention. For postoperative analgesia the penile nerve block and caudal block have been using as common techniques.(1) While providing effective post- operative analgesia, the caudal block method can have adverse side effects such as subarachnoid, intraosseous and intravascular puncture, motor block and delayed postoperative micturition.(2). Pudendal nerve block may be an alternative block to other blocks in circumcision. The pudendal nerve is a peripheral nerve with both mo- tor and sensorial innervation of penis.(3) Some recent studies have reported that pudendal block provided bet- ter analgesia than caudal block in hypospadias surgery and also had shorter hospital discharge time which is an important topic for circumcision surgery.(4,5) In this prospective, randomized double blind study, we 1Cerrahpasa Medical Faculty, Department of Anesthesiology and Reanimation, Istanbul, TURKEY. 2Cerrahpasa Medical Faculty, Department of Pediatric Surgery, Istanbul TURKEY. *Correspondence: Cerrahpasa Medical Faculty, Department of Anesthesiology and Reanimation Cerrahpasa Medical Faculty, Ko- camustafapasa, Istanbul, 34280, TURKIYE. Tel: +90 212 414300-2187 GSM: + 90 532 592 0584. Fax: +90 212 41422766. E-mail: actutuncu@gmail.com. Received November 2017 & Accepted December 2017 aimed to compare the postoperative pain intensity and additional analgesic use after the application of dorsal penile nerve block and nerve stimulator guided puden- dal nerve block in children undergoing circumcision. MATERIALS AND METHODS Study population and inclusion criteria The study enrolled 85 children with ASA (American Society of Anesthesiologist Physical Status) I-II and in the age range of 1-10 years, planned to undergo cir- cumcision, after obtaining the hospital ethical commit- tee approval and the informed written consent of the parents. (Ethical approval no: 242893, Clinical trial no: NCT03258255) Exclusion criteria Children with neurological or neuromuscular disorders, a history of hemorrhage or coagulation disorders were not included in the study. After premedication with midazolam, the patients were taken into the operating room, for application of the ap- propriate monitoring and anesthesia induction achieved with propofol (2-3mg/kg), fentanyl (0.5 mcg/kg) and 2% sevoflurane. Laryngeal mask airway of the ap- propriate number was inserted without neuromuscular blocker administration and maintenance of anesthesia was provided with 2% sevoflurane. The patients’ randomization was performed with sealed enveloped techniques (based on computer-generated random numbers), and they were randomly divided into two groups, as the penile nerve block group (PNB- Group) or the nerve stimulator guided pudendal nerve block group (PDB-Group). Procedure In penile nerve block group (PNB group), dorsal pe- nile block was achieved by two surgeons in the supine position, after skin sterilization, by palpating the sym- physis pubis and perforating the Scarpa’s fascia with a pop feeling by 25 G needle and injecting 0.25 % bu- pivacaine mixture of 0.3 ml/kg volume on the midline into the dorsal base of penis, between the pubis and the penis under Scarpa’s fascia. In pudendal nerve block group (PDB group ) Pudendal nerve block was performed by same two anesthesiolo- gists a in the lithotomy position, after the appropriate skin sterilization. The nerve stimulator was adjusted to 3mA and 2Hz, and the stimulator needle (22-24 G Stimuplex A, 50-100mm, B. Braun, Melsungen, Ger- many) was inserted from the inferomedial of ischial tuberosities while palpating the tuberosities located at position of 3 and 9 o’clock of the anus (Figure 1). Bu- pivacaine administered as a 0.25 % mixture at 0.3 ml/ kg volume. Injection was performed bilaterally after the perineal muscle contraction and the up-down penile movements. Dorsal penile nerve blocks were performed by two experienced pediatric surgeons and the puden- dal nerve blocks were performed by two experienced anesthetists. Pain Evaluation The primary outcome was the assessment of postopera- tive pain intensity and analgesic usage in the postopera- tive period. All patients were evaluated in the pediatric recovery room by two different anesthesiologists who did not know which technique was performed for anal- gesia during the surgery. The secondary outcome was to evaluate the hemodynamic response of the blocks during surgery. Surgical incision was made minimally 15 minutes after the block. Before and after the block, the heart rate and the noninvasive arterial blood pressure were recorded first 5th minutes then every ten minutes during the sur- gery by anesthetists who performed the block and cared the patient during surgery. If any increase over 20% was seen, remifentanil infusion (0.1 mcg/kg/min) was started and the dose was increased if necessitated. In the postoperative period, after the patient was transferred to the recovery unit, the modified Children Hospital of Eastern Ontario Pain Scale (m CHEOPS) was used. The modified CHEOPS is an observational scale including five parameters of pain behavior which is scaling cry- ing, facial expression, verbal response and body posture to assess the pain intensity of children aged between 1- 5-year-old, (mCHEOPS: 0 = no pain; 10 = severe pain) In this study the pain score which needs treatment was described as mCHEOPS 5 or higher score (Figure 2). The pain evaluation was performed at the postoper- ative 5th and the 30th minutes and the first and second hours. When mCHEOPS score was above 5, tramadol (1 mg/kg) was used. The postoperative pain evaluation and the analgesic applications were carried out by the recovery unit anaesthetists who were blinded to the type of nerve block technique. All patients were sent home after an average of 2 hours after the operation, when the control of pain, consciousness, nausea, vom- iting and surgical complications were completed and the first nourishment had been provided. At home, pain evaluations were made at the postoperative 6th, 12th, 18th and the 24th hours by the patients’ families using the Faces Pain Scale. The families, blind to the type of nerve block performed on the patient, were previously instructed on the postoperative pain evaluation which was made easy by the selective use of the Faces Pain Scale forms illustrated with faces expressing different degrees of pain. Use of ibuprofen (10mg/kg-orally) was recommended when the pain score of the patient was above 4. Sample size The sample size was estimated on the basis of the num- ber of patients per group. It has been suggested to be 35 with at least 40 % difference in pain scores between two groups with a power of 95 % at the 5 % significance level. Statistical analysis The statistical analyses were carried out using the SPSS 15.0 package program for Windows. For the numerical data, descriptive analyses with the mean, the standard deviation and the median were employed. Percentages were used for the categorical data. The Student t-test was used for the normally distributed numerical vari- ables in two independent groups. When normal distri- Table 1. Demographic data. Pudendal Block (n=39) Penile Block (n=39) Mean ± SD Min-Max Mean ± SD Min-Max p-value Age (month) 44.1 ± 23.9 6-96 46.2 ± 32.7 9-120 .714 Weight (kg) 17.0 ± 7.6 6.5-39 17.7 ± 7.5 8-35 .779 Pudendal Block (n=39) Penile Block (n=39) Mean ± SD Median Mean ± SD Median Mean Difference p-value mCHEOPS 5.min 3.79 ± 0.80 4 (3-4) 8.95 ± 2.24 10 (6-11) -5.16 < 0.001 30.min 3.69 ± 0.77 4 (3-4) 5.74 ± 1.02 6 (5-6) -2.05 < 0.001 1.h 3.62 ± 0.92 4 (3-4) 5.23 ± 0.43 5 (5-5) -1.61 < 0.001 2.h 3.84 ± 1.12 4 (3-5) 5.21 ± 0.41 5 (5-5) -1.37 < 0.001 6.h 3.65 ± 1.01 4 (3-4) 5.85 ± 1.16 6 (5-6) -2.20 < 0.001 12.h 3.81 ± 1.05 4 (3,5-4) 6.59 ± 0.99 6 (6-8) -2.78 < 0.001 18.h 3.81 ± 0.97 4 (4-4) 7.13 ± 0.73 7 (7-8) -3.32 < 0.001 24.h 4.46 ± 1.24 5 (4-5) 7.10 ± 0.31 7 (7-7) -2.64 < 0.001 Table 2. Comparison of mCHEOPS scores between Pudendal block and Penile block. Pudendal vs penile nerve block in circumcision- Tutuncu et al. Pediatric Urology 32 Vol 15 No 03 May-June 2018 33 bution was not observed, the Mann-Whitney U test was employed. Ratio comparisons between the data on the two groups of patients were carried out by the Chi-Square analysis, the alpha significance level was rated by the P < .05 value. RESULTS Although 85 children were included the study, seven- ty-eight children were eligible for analysis, thirty-nine patients were evaluated for each group; accurately sev- en patients had to be excluded from the study; at begin- ning of the study, one of them had a neurological disor- der, two of patients had hematological disease, and four of patients had incomplete pain evaluation expected to be made at home (Figure 3). There were not signifi- cant differences between groups with respect to age and body weight (Table 1). For the primary outcome, the postoperative pain eval- uation by mCHEOPS scores were significantly high- er in the PNB-Group than in the PDB-Group at each measurement time (Table 2). Statistically significant differences in the mCHEOPS levels of the patient groups were determined in follow up (P < .001, for both groups). In the PDB-Group, significant change did not occur in the mCHEOPS level until the postopera- tive 18th hour. The increase at the 24th hour was sig- nificant as compared to the levels at the postoperative 5th minute and the 18th hour (P < .001 and P = .001, respectively). In the PNB-Group significant falls were observed at the postoperative 30th minute vs the 5th minute and at the postoperative 1st hour vs the level at the 30th minute; with a significant elevation at the postoperative 6th hour vs the 2nd hour (P = .003). At the postoperative 24th hour the mean mCHEOPS score was significantly lower than that at the postoperative 5th minute (P < .001) (Table 3). At the postoperative 5th minute a 38.4% additional anal- gesia requirement was observed in the PNB-Group. At follow up, the needs for additional analgesia were 0%, 7.7%, 30.8%, 46.2%, 59% and 59% at, respectively, the postoperative 30th minute, 1st, 2nd, 6th,12th, 18th and 24th hours. In the PDB-Group none of the patients needed additional analgesia until the postoperative 24th hour, when 75.7% of the patients had to receive addi- tional analgesia. The requirement for extra analgesia at the postoperative 24th hour of the two groups did not differ significantly (P = .121) (Table 4). In the perioperative period only two patients of the PDB-Group required remifentanil use during the first 10 minutes, while 18 patients in the PNB-Group re- quired remifentanil use (Table 5). The initial mean sys- tolic blood pressure (SBP) of the two groups did not dif- fer significantly (P = .871). The mean SBP levels of the PDB-Group were significantly lower as compared to those of the PNB-Group between the 5th minute and the 20th minute after the incision (respectively, P < .001, P = .037, P = .018, P < .001, P = .001, and P < .001). However, the mean SBP of the groups did not differ significantly at the 20th minute (P = .058). Intragroup SBP levels of both groups did not differ significantly (P < .001, for both groups) (Table 6). The initial mean diastolic blood pressure (DBP) of the two groups did not differ significantly (P = .308). The 5th minute mean DPB of the PDB-Group was signif- icantly lower as compared to that of the PNB-Group (P = .006). The mean DBP of the two groups did not differ significantly at the 10th minute and before the incision (P = .100 and P = .308). After the incision, the mean DBP of the PDB-Group was statistically lower than those of the PNB-Group. While significant fall in the DBP as compared to the initial levels was observed in the PDB-Group (P < .001), in the PNB-Group sig- nificant fall was observed at all timings except at the perioperative 20th minute (P < .001). The initial mean heart rate (HR) of the two groups did not differ significantly (P =.197). At the 5th minute af- ter incision, the mean HR of the PDB-Group was sig- nificantly lower than that of the PNB-Group (P < .001). However, statistically significant intergroup differences were not observed in the mean HR at other timings. No surgical complications were detected in the studied patients. DISCUSSION Circumcision is one the most painful surgical proce- Table 3. Comparison of mCHEOPS scores within groups Pudendal Block Penile Block p value p value CHEOPS 30.min - CHEOPS 5.min .285 < 0.001 CHEOPS 1.h - CHEOPS 30.min .564 .002 CHEOPS 2.h - CHEOPS 1.h .088 .564 CHEOPS 6.h - CHEOPS 2.h .200 .003 CHEOPS 12.h - CHEOPS 6.h .201 .009 CHEOPS 18.h - CHEOPS 12.h 1.000 .026 CHEOPS 24.h - CHEOPS 18.h < .001 .835 CHEOPS 24 h - CHEOPS 5.min .001 < 0.001 Pudendal Block Penile Block n % n % P Additional analgesic 5.min 0 0.0 15 38.4 < 0.001 30.min 0 0.0 0 0.0 - 1.h 0 0.0 3 7.7 .241 2.h 0 0.0 3 7.7 .241 6.h 0 0.0 12 30.8 < 0.001 12.h 0 0.0 18 46.2 < 0.001 18.h 0 0.0 23 59.0 < 0.001 24.h 28 75.7 23 59.0 .121 Table 4. Comparison of additional analgesic requirements Pudendal vs penile nerve block in circumcision- Tutuncu et al. dures performed on the pediatric patient. It is obliga- tory to reduce postoperative pain of this outpatient sur- gery. Application of different anaesthetic and analgesic methods have been reported in the literature.(6) The most frequently reported methods are topical analgesia, and caudal and penile nerve blocks with each method resulting in different requirements of analgesia and in- cidences of side effects. In caudal nerve block, complications specific to cen- tral block can be seen. Penile nerve block is simpler to perform than the caudal block and does not involve complications such as delayed mobilization and uri- nary retention which delay discharge from hospital. (7) However, complications including hematoma and edema development and anesthetic toxicity have been reported with penile nerve block which can be applied by differing approaches such as the dorsal penile nerve block or subcutaneous ring infiltration.(8) In this study, we have used the dorsal penile nerve block method. The dorsal penile nerve is a branch of the pudendal nerve and innervates the penile shaft, the urethra and the glans penis.(9) The results of this study have indicated an achievement of better analgesic effect with puden- dal nerve block as compared to the dorsal penile nerve block which also resulted in reduced postoperative an- algesic use. Less effective analgesia was observed after dorsal penile nerve block. Faraoini et al. performed penile nerve block guided by ultrasonography (USG) or by using anatomical land- marks for circumcision of 40 children. Although there were no differences in the block failure in the two ap- proaches, the USG-guided approach was observed to provide more effective analgesia and less use of analge- sics. They reported that visualization of the dorsal pe- nile nerve and the spread of the local anaesthetic during the application of the block increased the effectiveness of the penile nerve block.(10) Sademan et al., using a similar approach with the as- sistance of USG or by use of anatomical indicators for penile nerve block, also reported that the use of periop- erative opioids were reduced and better analgesia was provided by the USG-guided procedure. They reported that the one sided spread of the local anaesthic visual- ized by the USG aided nerve block, reduced the effec- tiveness of the nerve block.(11) It has been reported in the literature that the mean failure incidence of penile nerve block is 3-10% and that 30% of the patients require pe- rioperative and postoperative additional analgesia.(11,12) In our study, as high as 38.4% of the patients operated with dorsal penile nerve block have required extra anal- gesic administration, and the possibility of not having blocked the scrotal branch of the pudendal nerve as well as the penile nerve may be considered to have contrib- uted to this result. Studies on circumcisions performed by blocking the scrotal nerve and the dorsal penile nerve, which is not the routine method of penile block for circumcision, have reported increased analgesic ef- fectiveness. In this respect, the routine pudendal nerve block is a better choice of analgesia as compared to the routine approach of penile nerve block.(13,14) Pudendal nerve originates from the sacral nerve roots 2, 3 and 4; passes between the sacrospinous and sac- rotuberous ligaments in the pelvis, passes through the pudendal canal and supplies the dorsal penile nerve, the inferior anal nerve and the scrotal skin innervation. (15) The ischial tuberosity, that the sacrotuberous liga- ment is attached to, is used as an anatomical indicator for determining the location of the pudendal nerve in our study.(3) This involves a more lateral entry point as compared to the method of Naja(14) comparing the pu- Table 5. Comparison of remifentanil (RF) usage percentage and dosage in perioperative period Pudendal Block Penile Block n % n % p RF (%) Beginning 0 0.0 1 2.6 1.000 1.min 0 0.0 0 0.0 - 5.min 0 0.0 0 0.0 - 10.min 0 0.0 0 0.0 - Before incision 0 0.0 1 2.6 1.000 Incision 1. min 0 0.0 26 66.7 <0.001 ncision 5. min 2 5.1 23 84.6 <0.001 ncision 10.min 2 5.1 23 84.6 < 0.001 ncision 20.min 0 0.0 33 84.6 < 0.001 Pudendal Block Penile Block Mean ± SD Median Mean± SD Median p* RF mcg/kg/min Before incision 0.05 Incision 1. Min 0.13 ± 0.06 0.1 Incision 5. min 0.05 ± 0.00 0.05 0.16 ± 0.05 0.2 - Incision 10. Min 0.05 ± 0.00 0.05 0.17 ± 0.05 0.2 - Incision 20. Min 0.14 ± 0.05 0.1 *sample size was not sufficient enough to create a p value Figure 1. Pudendal block application area. Pudendal vs penile nerve block in circumcision- Tutuncu et al. Pediatric Urology 34 Vol 15 No 03 May-June 2018 35 dendal and penile nerve block methods in circumcision. Schmidt, on the other hand, has argued for the use of the ischial tuberosity for determining the ischial spine as the most suitable point for perineal approach to pu- dendal innervation.(16) In our study, 0.3 ml/kg, 0.25% bupivacaine was used for both the penile and the pu- dendal nerve blocks. Sfez et al. used 0.25 and 0.5 mg/ kg bupivacaine for penile nerve block, achieving equiv- alent analgesic effectiveness with both doses, without differences in the time for peaking although the serum bupivacaine concentration was higher with the 0.5 mg/ kg dosage but remained below the 4 mcg/ml limit of toxicity. In our study 0.75 mg/kg bupivacaine was used but the serum concentration was not determined. How- ever, indications of local anaesthetic toxicity were not observed.(17) In another study on comparison of penile nerve and pudendal nerve block for circumcision,(14) lidocaine, fentanyl and clonidine were used. In this study, the time of discharge from hospital was given to vary between 2 and 6 hours. There were no differences in the arterial blood pressure and heart rate data in the two procedures. The better analgesia and less analgesic use achieved by this study in comparison to the out- comes in our PNB-group is attributed to the addition- al use of opioids and clonidine. In our routine surgery procedure, the mean time of discharge is 2 hours in the absence of complications which was achieved with all patients of our study. Also, in our study the mean sys- tolic blood pressure of the PDB-Group of patients was significantly lower in comparison to the PNB-Group of patients and this was attributed to the effective and pro- found analgesia provided by the pudendal nerve block method. One of the limitations of ours study is not recording the exact time of the initial use of rescue analgesics. Anoth- er limitation is having relied on parents to evaluate the postoperative pain severity. The single disadvantage of the pudendal nerve block is placing the patient in the lithotomy position and the pro- longing of the preoperative procedures by the prepara- tive and application procedures of the pudendal nerve block. These details, however, have been overlooked in Penile Block Pudendal Block Mean ±SD Median Mean ± SD Median p value Systolic BP Beginning 96.3 ± 22.3 98 96.9 ± 10.1 96 .871 5.min 81.3 ± 9.1 79 91.7 ± 13.5 92 <0 .001 10.min 84.5 ± 9.5 85 89.7 ± 12.2 90 .037 Before incision 82.8 ± 10.1 83 88.9 ± 11.9 90 .018 Incision 5.min 83.4 ± 8.3 82 93.0 ± 16.8 89 .001 Incision 10.min 80.5 ± 8.4 79 91.7 ± 15.1 88 < 0.001 Incision 20.min 80.7 ± 9.6 79 86.3 ± 14.9 84 .058 Penile Block Pudendal Block Mean.±SD Median Mean.±SD Median p value Diastolic KB Beginning 61.2 ± 16.1 60 57.3 ± 8.7 56 .308 5.min 48.9 ± 9.0 45 53.9 ± 10.9 52 .006 10.min 47.8 ± 8.8 46 52.3 ± 9.0 52 .100 Before incision 48.8 ± 9.2 46 51.2 ± 8.6 52 .308 Incision 5.min 48.1 ± 8.6 45 55.3 ± 10.8 53 < 0.001 Incision 10.min 46.9 ± 6.7 45 55.7 ± 14.8 52 < 0.001 Incision 20.min 46.5 ± 7.4 45 57.6 ± 18.1 52 < 0.001 Penile Block Pudendal Block Mean ±SD Median Mean ± SD Median p value HR Beginning 112.4±30.3 114 121.6±20.9 122 .197 5.min 109.2±15.5 104 115.3±20.5 120 .086 10.min 104.8±16.0 98 111.8±19.6 114 .057 Before incision 104.6±15.1 104 110.3±18.4 110 .068 Incision 5. min 103.9±14.2 102 117.4±18.0 121 < 0.001 Incision 10. min 100.7±13.2 99 107.9±15.0 110 .060 Incision 20. min 98.0±9.9 96 96.7±15.0 96 .657 Table 6. Comparison of hemodynamic parameters between groups Figure 2. Modified Cheops Score. Pudendal vs penile nerve block in circumcision- Tutuncu et al. view of the better analgesic effectiveness and patient comfort achieved by pudendal nerve block approach. CONCLUSIONS In conclusion, we observed that the pudendal nerve block has provided a better analgesic effect and less use of postoperative analgesics as compared the dorsal penile nerve block. Pudendal block provided very com- fortable and painless postoperative period in circumci- sion surgery, and seems to be a more favorable option relative to penile block. CONFLICT OF INTEREST Authors declare that they have no conflict of interest. REFERENCES 1. Cyna AM, Middleton P. Caudal epidural block versus other methods of postoperative pain relief for circumcision in boys. Cochrane Database Syst Rev. 2008; 8: 2-6. 2. Dalens B, Vanneuville G, Dechelotte P Penile block via the subpubic space in 100 children. Anesth Analg. 1989; 1: 41-5. 3. Reitz A, Gobeaux N, Mozer P, Delmas V, Richard F, Chartier-Kastler E. Topographic anatomy of a new posterior approach to the pudendal nerve for stimulation. Eur Urol. 2007; 5 : 1350-5. 4. Kendigelen P, Tutuncu AC Emre S, Altindas F, Kaya G. Pudendal versus caudal block in children undergoing hypospadias surgery: A randomized controlled study Reg Anesth Pain Med. 2016; 5: 610-5. 5. Hecht S, Piñeda J, Bayne A. Ultrasound- guided pudendal block is a viable alternative to caudal block for hypospadias surgery: a single surgeon pilot study. Urology 2017; S0090-4295: 31197-4. 6. Bellieni CV, Alagna MG, Buonocore G. Analgesia for infants' circumcision Ital J Pediatr. 2013; 39: 1-7. 7. Allan CY, Jacqueline PA, Shubhda JH. Caudal epidural block versus other methods of postoperative pain relief for circumcision in boys. Cochrane Database Syst Rev. 2003; 2: 2-8. 8. Soh CR1, Ng SB, Lim SL. Dorsal penile nerve block. Paediatr Anaesth. 2003; 4: 329-33. 9. Yang CC, Bradley WE. Neuroanatomy of the penile portion of the human dorsal nerve of the penis. B J Urol. 1998; 82: 109-113. 10. Faraoni D, Gilbeau A, Lingier P, Barvais L, Engelman E, Hennart D. Does ultrasound guidance improve the efficacy of dorsal penile nerve block in children? Paediatr Anaesth. 2010; 10: 931-6. 11. Sandeman DJ1, Dilley AV. Ultrasound guided dorsal penile nerve block in children. Anaesth Intensive Care. 2007; 2: 266-9. 12. Brown TCK, Weidner NJ, Bouwmeester J. Dorsal nerve of the penis block-anatomical and radiological studies. Anaesth Intensive Care. 1989; 17: 34-8. 13. Serour F, Mori J, Barr J. Optimal regional anesthesia for circumcision. Anesth Analg. 1994; 79: 129-31. 14. Naja Z, Al-Tannir MA, Faysal W, Daoud N, Ziade F, El-Rajab M. A comparison of pudendal block vs dorsal penile nerve block for circumcision in children: a randomized controlled trial. Anesthesia. 2011; 9: 802-7. Figure 3. Flowchart of Consort diagram of patients’ selection Pudendal vs penile nerve block in circumcision- Tutuncu et al. Pediatric Urology 36 Vol 15 No 03 May-June 2018 37 15. Hruby S, Ebmer J, Dellon AL, Aszmann OC. Anatomy of pudendal nerve at urogenital diaphragm--new critical site for nerve entrapment. Urology. 2005; 5: 949-52. 16. Schmidt RA. Technique of pudendal nerve localization for block or stimulation. J Urol. 1989; 6: 1528-31. 17. Sfez M, Le Mapihan Y, Mazoit X, Dreux- Boucard H. Local anesthetic serum concentrations after penile nerve block in children. Anesth Analg. 1990; 4: 423-6. Pudendal vs penile nerve block in circumcision- Tutuncu et al.