Biofeedback combined with percutaneous electrical pudendal nerve stimulation for the treatment of low anterior rectal resection syndrome: a study protocol for a randomized controlled trial.

BACKGROUND: Low anterior resection syndrome (LARS) is a distressing condition that affects approximately 25-80% of patients following surgery for rectal cancer. LARS is characterized by debilitating bowel dysfunction symptoms, including fecal incontinence, urgent bowel movements, and increased frequency of bowel movements. Although biofeedback therapy has demonstrated effectiveness in improving postoperative rectal control, the research results have not fulfilled expectations. Recent research has highlighted that stimulating the pudendal perineal nerves has a superior impact on enhancing pelvic floor muscle function than biofeedback alone. Hence, this study aims to evaluate the efficacy of a combined approach integrating biofeedback with percutaneous electrical pudendal nerve stimulation (B-PEPNS) in patients with LARS through a randomized controlled trial (RCT). METHODS AND ANALYSIS: In this two-armed multicenter RCT, 242 participants with LARS after rectal surgery will be randomly assigned to undergo B-PEPNS (intervention group) or biofeedback (control group). Over 4 weeks, each participant will undergo 20 treatment sessions. The primary outcome will be the LARS score. The secondary outcomes will be anorectal manometry and pelvic floor muscle electromyography findings and the European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire-Colorectal 29 (EORTC QLQ-CR29) scores. Data will be collected at baseline, post-intervention (1 month), and follow-up (6 months). DISCUSSION: We anticipate that this study will contribute further evidence regarding the efficacy of B-PEPNS in alleviating LARS symptoms and enhancing the quality of life for patients following rectal cancer surgery. TRIAL REGISTRATION: Chinese Clincal Trials Register ChiCTR2300078101. Registered 28 November 2023.

Efficacy of ganglion impar block combined with pudendal nerve pulsed radiofrequency for pudendal neuralgia management-a randomized clinical trial.

BACKGROUND: Pudendal neuralgia is a chronic and debilitating condition. Its prevalence ranges from 5 to 26%. Currently, therapeutic approaches to treat pudendal neuralgia include patient education, medication management, psychological and physical therapy, and procedural interventions, such as nerve block, trigger point injections, and surgery. Drug therapy has a limited effect on pain relief. A pudendal nerve block may cause a significant decrease in pain scores for a short time; however, its efficacy significantly decreases over time. In contrast, pudendal nerve pulsed radiofrequency can provide pain relief for 3 months, and ganglion impar block has been widely used for treating chronic perineal pain and chronic coccygodynia. This study aimed to determine the efficacy and safety of monotherapy (pudendal nerve pulsed radiofrequency) and combination therapy (pudendal nerve pulsed radiofrequency plus ganglion impar block) in patients with pudendal neuralgia. METHODS: This randomized, controlled clinical trial will include 84 patients with pudendal neuralgia who failed to respond to drug or physical therapy. Patients will be randomly assigned into one of the two groups: mono or combined treatment groups. The primary outcome will be a change in pain intensity measured using the visual analog scale. The secondary outcomes will include a Self-Rating Anxiety Scale score, Self-Rating Depression Scale score, the use of oral analgesics, the Medical Outcomes Study Health Survey Short Form-36 Item score, and the occurrence of adverse effects. The study results will be analyzed using intention-to-treat and per-protocol analyses. Primary and secondary outcomes will be evaluated between the mono and combined treatment groups. Subgroup analyses will be conducted based on the initial ailment, age, and baseline pain intensity. The safety of the treatment will be assessed by monitoring adverse events, which will be compared between the two groups. DISCUSSION: This study protocol describes a randomized, controlled clinical trial to determine the efficacy and safety of mono and combination therapies in patients with pudendal neuralgia. The study results will provide valuable information on the potential benefits of this combination therapy and contribute to the development of more effective and safer treatments for patients with pudendal neuralgia. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR2200061800).

Pudendal nerve neurolysis outcomes for urogenital and rectal disorders in patients suffering from pudendal nerve entrapment: A systematic review.

PURPOSE: Pudendal neuropathy is an uncommon condition that exhibits several symptoms depending on the site of nerve entrapment. This study aims to evaluate the efficacy of pudendal nerve neurolysis (PNN) in improving lower urinary tract symptoms, anal and/or urinary incontinence, and sexual dysfunctions. MATERIALS AND METHODS: A systematic literature search was performed on 20 May 2023 using Scopus, PubMed, and Embase. Only English and adult papers were included. Meeting abstracts and preclinical studies were excluded. RESULTS: Twenty-one papers were accepted, revealing significant findings in the field. The study identified four primary sites of pudendal nerve entrapment (PNE), with the most prevalent location likely being at the level of the Alcock canal. Voiding symptoms are commonly exhibited in patients with PNE. PNN improved both urgency and voiding symptoms, and urinary and anal incontinence but is less effective in cases of long-standing entrapment. Regarding sexual function, the recovery of the somatic afferent pathway results in an improvement in erectile function early after neurolysis. Complete relief of persistent genital arousal disorder occurs in women, although bilateral PNN is necessary to achieve the efficacy. PNN is associated with low-grade complications. CONCLUSIONS: PNN emerges as a viable option for addressing urinary symptoms, fecal incontinence, erectile dysfunction, and female sexual arousal in patients suffering from PNE with minimal postoperative morbidity.

Comparison of the effects of ring block and dorsal penile nerve block on parental satisfaction for circumcision operation in children: randomized controlled trial.

PURPOSE: In children, circumcision is a procedure associated with perioperative pain and parental satisfaction is an important parameter in the evaluation of anesthesia procedures. Inadequate dorsal penile nerve block (DPNB) for the ventral shaft of the penis might impact parental satisfaction negatively. To evaluate this hypothesis, we compared the effects of penile ring block (RB) and dorsal penile nerve block (DPNB) on parental satisfaction. Postoperative pain, need for additional analgesia, intraoperative hemodynamic data, recovery status, side effects, and postoperative complications were evaluated as secondary outcomes between the blocks. METHODS: Parental satisfaction and anesthetic effectiveness of RB and DPNB for circumcision in children were compared. 86 patients were randomized 1:1 to Group RB and Group DPNB, which were administered the same dose of anesthesia. Parental satisfaction was evaluated with the Pediatric Anesthesia Parental Satisfaction Questionnaire (PAPS). Postoperative pain evaluations were made with the Face, Legs, Activity, Crying, Consolability Pain Scale (FLACC). RESULTS: In terms of parent satisfaction, no differences were detected between the groups in the pre-anesthesia, pre-anesthesia and post-anesthesia, post-anesthesia, hospital team, and anesthesia team parameters (p > 0.05). The scores of Group DPNB patients were higher only in the "Q11" subparameter in the "anesthesia team" parameter, and this difference was significant (0.024). CONCLUSION: RB and DPNB were compared in circumcision, which is the most common surgical procedure for children. Parental satisfaction, anesthesia, and analgesic effects of both blocks were found to be similar. CLINICAL TRIALS: ACTRN12622001211752.

Accuracy of augmented reality-guided needle placement for pulsed radiofrequency treatment of pudendal neuralgia: a pilot study on a phantom model.

Background: Pudendal neuralgia (PN) is a chronic neuropathy that causes pain, numbness, and dysfunction in the pelvic region. The current state-of-the-art treatment is pulsed radiofrequency (PRF) in which a needle is supposed to be placed close to the pudendal nerve for neuromodulation. Given the effective range of PRF of 5 mm, the accuracy of needle placement is important. This study aimed to investigate the potential of augmented reality guidance for improving the accuracy of needle placement in pulsed radiofrequency treatment for pudendal neuralgia. Methods: In this pilot study, eight subjects performed needle placements onto an in-house developed phantom model of the pelvis using AR guidance. AR guidance is provided using an in-house developed application on the HoloLens 2. The accuracy of needle placement was calculated based on the virtual 3D models of the needle and targeted phantom nerve, derived from CBCT scans. Results: The median Euclidean distance between the tip of the needle and the target is found to be 4.37 (IQR 5.16) mm, the median lateral distance is 3.25 (IQR 4.62) mm and the median depth distance is 1.94 (IQR 7.07) mm. Conclusion: In this study, the first method is described in which the accuracy of patient-specific needle placement using AR guidance is determined. This method could potentially improve the accuracy of PRF needle placement for pudendal neuralgia, resulting in improved treatment outcomes.

Short-Term Dorsal Genital Nerve Stimulation Increases Subjective Arousal in Women With and Without Spinal Cord Injury: A Preliminary Investigation.

OBJECTIVES: Female sexual dysfunction (FSD) affects an estimated 40% of women. Unfortunately, FSD is understudied, leading to limited treatment options for FSD. Neuromodulation has shown some success in alleviating FSD symptoms. We developed a pilot study to investigate the short-term effect of electrical stimulation of the dorsal genital nerve and tibial nerve on sexual arousal in healthy women, women with FSD, and women with spinal cord injury (SCI) and FSD. MATERIALS AND METHODS: This study comprises a randomized crossover design in three groups: women with SCI, women with non-neurogenic FSD, and women without FSD or SCI. The primary outcome measure was change in vaginal pulse amplitude (VPA) from baseline. Secondary outcome measures were changes in subjective arousal, heart rate, and mean arterial pressure from baseline. Participants attended one or two study sessions where they received either transcutaneous dorsal genital nerve stimulation (DGNS) or tibial nerve stimulation (TNS). At each session, a vaginal photoplethysmography sensor was used to measure VPA. Participants also rated their level of subjective arousal and were asked to report any pelvic sensations. RESULTS: We found that subjective arousal increased significantly from before to after stimulation in DGNS study sessions across all women. TNS had no effect on subjective arousal. There were significant differences in VPA between baseline and stimulation, baseline and recovery, and stimulation and recovery periods among participants, but there were no trends across groups or stimulation type. Two participants with complete SCIs experienced genital sensations. CONCLUSIONS: To our knowledge, this is the first study to measure sexual arousal in response to short-term neuromodulation in women. This study indicates that short-term DGNS but not TNS can increase subjective arousal, but the effect of stimulation on genital arousal is inconclusive. This study provides further support for DGNS as a treatment for FSD.

Nerve transfer for restoration of lower motor neuron-lesioned bladder, urethral and anal sphincter function. Part 4: Effectiveness of the motor reinnervation.

In pilot work, we showed that somatic nerve transfers can restore motor function in long-term decentralized dogs. We continue to explore the effectiveness of motor reinnervation in 30 female dogs. After anesthesia, 12 underwent bilateral transection of coccygeal and sacral (S) spinal roots, dorsal roots of lumbar (L)7, and hypogastric nerves. Twelve months postdecentralization, eight underwent transfer of obturator nerve branches to pelvic nerve vesical branches, and sciatic nerve branches to pudendal nerves, followed by 10 mo recovery (ObNT-ScNT Reinn). The remaining four were euthanized 18 mo postdecentralization (Decentralized). Results were compared with 18 Controls. Squat-and-void postures were tracked during awake cystometry. None showed squat-and-void postures during the decentralization phase. Seven of eight ObNT-ScNT Reinn began showing such postures by 6 mo postreinnervation; one showed a return of defecation postures. Retrograde dyes were injected into the bladder and urethra 3 wk before euthanasia, at which point, roots and transferred nerves were electrically stimulated to evaluate motor function. Upon L2-L6 root stimulation, five of eight ObNT-ScNT Reinn showed elevated detrusor pressure and four showed elevated urethral pressure, compared with L7-S3 root stimulation. After stimulation of sciatic-to-pudendal transferred nerves, three of eight ObNT-ScNT Reinn showed elevated urethral pressure; all showed elevated anal sphincter pressure. Retrogradely labeled neurons were observed in L2-L6 ventral horns (in laminae VI, VIII, and IX) of ObNT-ScNT Reinn versus Controls in which labeled neurons were observed in L7-S3 ventral horns (in lamina VII). This data supports the use of nerve transfer techniques for the restoration of bladder function.NEW & NOTEWORTHY This data supports the use of nerve transfer techniques for the restoration of bladder function.

Contribution of pudendal nerve injury to stress urinary incontinence in a male rat model.

Urinary incontinence is a common complication following radical prostatectomy, as the surgery disturbs critical anatomical structures. This study explored how pudendal nerve (PN) injury affects urinary continence in male rats. In an acute study, leak point pressure (LPP) and external urethral sphincter electromyography (EMG) were performed on six male rats with an intact urethra, the urethra exposed (UE), the PN exposed (NE), and after PN transection (PNT). In a chronic study, LPP and EMG were tested in 67 rats 4 days, 3 weeks, or 6 weeks after sham PN injury, PN crush (PNC), or PNT. Urethras were assessed histologically. Acute PNT caused a significant decrease in LPP and EMG amplitude and firing rate compared to other groups. PNC resulted in a significant reduction in LPP and EMG firing rate 4 days, 3 weeks, and 6 weeks later. EMG amplitude was also significantly reduced 4 days and 6 weeks after PNC. Neuromuscular junctions were less organized and less innervated after PNC or PNT at all timepoints compared to sham injured animals. Collagen infiltration was significantly increased after PNC and PNT compared to sham at all timepoints. This rat model could facilitate preclinical testing of neuroregenerative therapies for post-prostatectomy incontinence.

Pudendal nerve blockade for persistent genital arousal disorder (PGAD): A clinical review and case report.

BACKGROUND: Persistent genital arousal disorder (PGAD) is a condition characterized by unwanted and potentially painful genital sensations or spontaneous orgasms without stimulation. We present a case of a 55-year-old woman with refractory genital arousal disorder that was treated with serial pudendal nerve blocks. CASE: RW is a 55-year-old woman with chronic pelvic pain, pudendal neuralgia, MDD, SI, GAD, CRPS, and persistent genital arousal disorder for 11 years. Her PGAD was refractory to conservative management, physical therapy, and bilateral clitoral artery embolization. We performed bilateral pudendal nerve blocks with Kenalog and Bupivacaine, which provided almost complete relief for 2-3 months. We performed a bilateral pudendal nerve radiofrequency ablation; however, there was minimal benefit. RW continues to have significant relief with serial pudendal nerve blocks. SUMMARY AND CONCLUSION: Persistent genital arousal disorder is often refractory to medication and physical therapy requiring significant intervention such as entrapment surgery or artery embolization. Our case demonstrates pudendal nerve blocks as a potential treatment modality with minimal side effects.

Can nerve monitoring during radical prostatectomy improve functional outcomes? A randomised trial.

OBJECTIVE: To explore how the use of the ProPep® Nerve Monitoring System (ProPep Surgical, Austin, TX, USA) for intraoperative specific sparing of the pudendal nerve fibres influences postoperative functional outcomes after unilateral nerve-sparing (UNS) or non-nerve-sparing (NNS) robot-assisted radical prostatectomy (RARP). PATIENTS AND METHODS: We randomised 100 men undergoing UNS or NNS RARP to ProPep nerve monitoring during RARP (intervention) or standard of care RARP (control). Functional outcomes were assessed at 3, 6, and 12 months using the International Consultation on Incontinence Questionnaire Short Form (ICIQ-SF), the International Prostate Symptom Score, the Danish Prostate Symptom Score, the International Index of Erectile Function, the Erection Hardness Scale, and 24-h pad tests. The primary outcome was the difference in ICIQ-SF score between the groups at 12 months. Secondary outcomes included differences in the remaining outcome measures and continence rates at all time points. Continence was defined as the use of no pads and the answer 'Never' to the question: 'How often do you experience urinary incontinence?' or a urine loss of <8 g on the 24-h pad test. RESULTS: A total of 82 patients were included in the per-protocol analysis at 12 months with 41 in each group. At 12 months the mean ICIQ-SF scores were 5.37 (95% confidence interval [CI] 3.71-7.03) and 5.66 (95% CI 4.05-7.27) for the intervention and control groups, respectively (P = 0.8). There were no statistically significant differences in any of the remaining outcomes. However, the continence rate was higher in the intervention group at 6 months (63% vs 44%, P = 0.09). CONCLUSIONS: Intraoperative nerve monitoring did not result in better functional outcomes following UNS or NNS RARP. Larger studies are needed to explore if ProPep can reduce the time to continence after RARP.

Use of pudendal nerve blocks in rubber band ligation of haemorrhoids: an Australia-wide cross-sectional analysis.

BACKGROUND: Surgeons vary in their approach to preventing pain post rubber band ligation (RBL) of haemorrhoids, with pudendal nerve blocks (PNB) being one analgesic strategy. No data exists on how commonly PNBs are used in RBL in Australia, and whether use varies by year and patient and hospital characteristics. METHODS: Aggregate data from the National Hospital Morbidity Database was obtained for all admissions for RBL in Australia from 2012 to 2021, with and without a PNB, overall and in relation to sex, age group, hospital remoteness, hospital sector, and year of procedure. Adjusted relative risks (adj. RR) of PNB were estimated using Poisson regression, mutually adjusting for all variables. RESULTS: Of the 346 542 admissions for RBL, 14013 (4.04%) involved a PNB. The proportion of patients receiving a PNB increased between 2012-2013 and 2020-2021, from 1.62% to 6.63% (adj. RR 3.99, CI 3.64-4.36). Patients most likely to receive a PNB were female (adj. RR 1.10; CI 1.07-1.14) aged 25-34 years (adj. RR 1.13; CI 1.01-1.26); in major-city (adj. RR 1.25 CI 1.20-1.30) and private hospitals (adj. RR 3.28 CI 3.13-3.45). CONCLUSION: This is the first published analysis of the use of PNB in RBL. Pudendal nerve block use has increased over time, with substantial variation in practice. Blocks were more than three times as likely to be used in private compared to public hospitals. If evidence supporting PNB use is established, equitable access to the procedure should be pursued.

Anatomical Relationships of the Sciatic Nerve and Pudendal Nerve to the Ischial Spine as They Exit the Greater Sciatic Foramen.

OBJECTIVE: Deep gluteal syndrome is a clinical condition in which discomfort may arise due to the pathoanatomy of the subgluteal space. We conducted an anatomical exploration to categorize the relationship of the piriformis muscle, sciatic nerve (SN), and pudendal nerve (PN) to the ischial spine (IS) and sacrospinous ligament. METHODS: We analyzed 22 cadavers. The piriformis muscle, SN, and PN were exposed through either a transgluteal approach or a gluteal flap. The relationship of the neural structures to the IS, sacrospinous ligament, and ischial bone as they exit the greater sciatic foramen was observed, and the exit zones were classified as zone A, medial to the IS (entirely on sacrospinous ligament); zone B, on the IS; and zone C, lateral to the IS (entirely on ischial bone). RESULTS: The SN was observed either in zone B or zone C in all specimens. The PN was found to be in either zone A or zone B in 97.6% of specimens. The most common combinations were SN in zone B and PN in zone A (type I), and SN in zone C and PN in zone B (type II). CONCLUSIONS: The results from this study show clear anatomical differences in the SN-PN relationship, which may play a role in pain seen in deep gluteal syndrome. Moreover, classification of the SN-IS and PN-IS relationships described in this article will help describe different pathologies affecting the deep gluteal area.

Swine Pudendal Nerve as a Model for Neuromodulation Studies to Restore Lower Urinary Tract Dysfunction.

Lower urinary tract dysfunction, such as incontinence or urinary retention, is one of the leading consequences of neurological diseases. This significantly impacts the quality of life for those affected, with implications extending not only to humans but also to clinical veterinary care. Having motor and sensory fibers, the pudendal nerve is an optimal candidate for neuromodulation therapies using bidirectional intraneural prostheses, paving the way towards the restoration of a more physiological urination cycle: bladder state can be detected from recorded neural signals, then an electrical current can be injected to the nerve based on the real-time need of the bladder. To develop such prostheses and investigate this novel approach, animal studies are still required since the morphology of the target nerve is fundamental to optimizing the prosthesis design. This study aims to describe the porcine pudendal nerve as a model for neuromodulation studies aiming at restoring lower urinary tract dysfunction. Five male farm pigs were involved in the study. First, a surgical procedure to access the porcine pudendal nerve without muscle resection was developed. Then, an intraneural interface was implanted to confirm the presence of fibers innervating the external urethral sphincter by measuring its electromyographic activity. Finally, the morphophysiology of the porcine pudendal nerve at the level of surgical exposure was described by using histological and immunohistochemical characterization. This analysis confirmed the fasciculate nature of the nerve and the presence of mixed fibers with a spatial and functional organization. These achievements pave the way for further pudendal neuromodulation studies by using a clinically relevant animal model with the potential for translating the findings into clinical applications.

Anatomy of the pudendal nerve in clinically important areas: a pictorial essay and narrative review.

PURPOSE: The pudendal nerve is an anatomical structure arising from the ventral branches of the spinal roots S2-S4. Its complex course may be affected by surrounding structures. This may result in irritation or entrapment of the nerve with subsequent clinical symptoms. Aim of this study is to review the anatomy of the pudendal nerve and to provide detailed photographic documentation of the areas with most frequent clinical impact which are essential for surgical approach. METHODS: Major medical databases were searched to identify all anatomical studies investigating pudendal nerve and its variability, and possible clinical outcome of these variants. Extracted data consisted of morphometric parameters, arrangement of the pudendal nerve at the level of roots, formation of pudendal nerve, position according to sacrospinal and sacrotuberal ligaments and its terminal branches. One female cadaver hemipelvis was dissected with common variability of separate course of inferior rectal nerve. During dissection photodocumentation was made to record course of pudendal nerve with focus on areas with recorded pathologies and areas exposed to iatrogenic damage during surgical procedures. RESULTS: Narrative review was done to provide background for photodocumentation. Unique photos of course of the pudendal nerve was made in areas with great clinical significance. CONCLUSION: Knowledge of anatomical variations and course of the pudendal nerve is important for examinations and surgical interventions. Surgically exposed areas may become a site for iatrogenic damage of pudendal nerve; therefore, unique picture was made to clarify topographic relations.

Pudendal Nerve Block With Liposomal Bupivacaine for Sacrospinous Ligament Suspension.

IMPORTANCE: Pudendal nerve block has been frequently used as a pain management modality for vaginal prolapse surgery. However, studies investigating its efficacy and the type of anesthetic used have had conflicting results. OBJECTIVE: This study aimed to evaluate the effect of intraoperative pudendal nerve block with liposomal bupivacaine on postoperative pain after sacrospinous ligament suspension surgery. STUDY DESIGN: In this single-blinded randomized controlled trial, 83 women undergoing sacrospinous ligament suspension were randomized to receive either intraoperative pudendal nerve block with liposomal bupivacaine or no block. Participants recorded their pain level on postoperative days (PODs) 1-3 and 7, the number of pain medication pills consumed, and the quality of their recovery using a validated questionnaire. RESULTS: There were no significant differences in pain scores between the groups on POD 1 and POD 3: 5 (2-6.25) versus 5.5 (4-8; P = 0.058) and 4 (1-6) versus 5 (2-7; P = 0.146), respectively. On POD 2, the overall pain score was statistically different between the groups, with the block group having lower interquartile ranges. This difference, however, was not clinically significant: 5 (1.75-5) versus 5 (3.25-7.75; P = 0.023). In the subset of participants who underwent a concomitant midurethral sling procedure, POD 2 and POD3 pain scores were significantly lower in those who received the block: 3 (1-5) versus 6 (5-8; P = 0.006) for POD 2 and 3 (1-5) versus 5 (3.250-7; P = 0.042) for POD 3. There were no significant differences in pain medication consumption or the quality of recovery scores. CONCLUSION: Pudendal nerve block with liposomal bupivacaine did not result in significant differences in postoperative pain after sacrospinous ligament suspension, except in those participants who underwent a concomitant midurethral sling procedure.

Intravenous dexamethasone does not prolong the duration of pudendal nerve block in infants and children undergoing hypospadias surgery: A randomized clinical trial.

BACKGROUND: The administration of intravenous dexamethasone increases the duration of neuraxial block and improves the quality of analgesia. However, little is known about these effects of dexamethasone on peripheral nerve blocks in children. AIMS: In this study, we aimed to investigate the benefit of intravenous dexamethasone for enhancing the effect of pudendal block on postoperative analgesia in children who underwent hypospadias surgery. METHODS: In total, 46 children aged 6-36 months who underwent hypospadias surgery were randomly allocated to either a control group (normal saline, group C) or dexamethasone group (0.5 mg/kg, group D). Pudendal block was performed before the surgery using 0.3 mL/kg of 0.225% ropivacaine on both sides. Parents were instructed to press the patient-controlled analgesia bolus button when their children's pain score was >4 points. The primary outcome measure was the time at which the first patient-controlled analgesia by proxy bolus dose was administered. The secondary outcome measures were pain score, number of patient-controlled analgesia administration by proxy bolus attempts, number of rescue analgesics required, total amount of fentanyl administered, and overall parental satisfaction. RESULTS: The time of first patient-controlled analgesia bolus administration by proxy was not different between the control and dexamethasone groups (5.6 [5.2, 8.8] h versus 6.5 [5.4, 8.1] h, hazard ratio 0.8, 95% confidence intervals 0.43 to 1.47, p = .46). There were no statistically significant differences among the secondary outcomes. CONCLUSIONS: Administration of intravenous dexamethasone did not enhance the duration of pudendal nerve block in infants and children aged 6-36 months who underwent hypospadias surgery.

Low-dose caudal versus dorsal penile nerve block for postoperative analgesia after circumcision: a randomized comparative study.

INTRODUCTION: Paediatric male circumcision is a painful surgical procedure, which is usually carried out under general anaesthesia. Regional analgesic techniques, including dorsal penile nerve block (DPNB) and caudal nerve block (CNB), are superior to opioid and non-opioid systemic analgesia for postoperative pain control after circumcision. MATERIAL AND METHODS: The purpose of our study was to compare the efficacy, duration of postoperative analgesia, and complications of DPNB, CNB, and the combination of 2 blocks. Eighty-one male patients aged from 3 to 12 years scheduled for circumcision were distributed into 3 groups, each consisting of 27 patients; group 1 (DPNB group), group 2 (CNB group), and group 3 for combined blockade. This study compared the 3 groups in terms of intraoperative vital signs: heart rate and blood pressure, postoperative Wong-Baker score, and complications (nausea, vomiting, pruritus, urinary retention, and constipation). RESULTS: The intraoperative haemodynamics did not differ between the 3 groups of the study. There is significant difference in the Wong-Baker scale postoperatively at 1, 3, and 24 hours, being significantly less in the CNB group and combined blockade group than in the DPNB group, but there was no significant difference between the CNB group and the combined blockade group. The incidence of complications showed no significant intergroup difference, except for urinary retention being lower with DPNB. CONCLUSIONS: Both caudal and combined blockade were superior to DPNB for intraoperative and postoperative analgesia after circumcision. CNB and combined blockade was associated with significantly higher incidence of urinary retention compared to DPNB. Also, there was no additional benefit to the analgesic efficacy from combining both blocks.

Bloqueos Nerviosos. Bases Anatómicas del Dolor Somático Abdomino-Pélvico / Nerve Blocks. Anatomy of the Somatic Innervation of the Abdomino-Pelvic Cavity

El dolor abdominal es una de las sintomatologías que afectan con frecuencia la cavidad abdomino-pélvica. Dicha cavidad posee una inervación somática en la que intervienen del séptimo a doceavo nervios intercostales, ramos colaterales y terminales del plexo lumbar y el nervio pudendo; siendo objetivo de este trabajo la descripción anatómica del dolor abdominopélvico a través del plexo lumbar, nervios intercostales y nervio pudendo, sus diferentes patrones y variaciones de conformación, y las implicancias de éstas últimas en las distintas maniobras clínico-quirúrgicas. Se realizó un estudio descriptivo, observacional y morfométrico de la inervación somática de la cavidad abdomino-pélvica, en 50 preparaciones cadavéricas, fijadas en solución de formaldehído, de la Tercera Cátedra de Anatomía, Facultad de Medicina, Universidad de Buenos Aires, entre Agosto/2017-Diciembre/2019. La descripción clásica del plexo lumbar se encontró en 35 casos; la presencia del nervio femoral accesorio en ningún caso; así como también la ausencia del nervio iliohipogástrico en ningún caso; el nervio obturador accesorio se halló en 2 casos; el nervio genitofemoral dividiéndose dentro de la masa muscular del psoas mayor en 6 casos; el nervio cutáneo femoral lateral emergiendo únicamente de la segunda raíz lumbar en 6 casos y por último se encontró la presencia de un ramo del nervio obturador uniéndose al tronco lumbosacro en un caso. Los nervios intercostales y el nervio pudendo presentaron una disposición clásica en todos los casos analizados. Es esencial un adecuado conocimiento y descripción del plexo lumbar, nervios intercostales y nervio pudendo para un adecuado abordaje de la cavidad abdomino-pélvica en los bloqueos nerviosos.

SUMMARY: Abdominal pain is one of the symptoms that affect the abdominal-pelvic cavity. The abdominal-pelvic cavity has a somatic innervation involving the seventh to twelfth intercostal nerves, collateral and terminal branches of the lumbar plexus and the pudendal nerve. The objective of this work is the description of the lumbar plexus, intercostal nerves and pudendal nerve, its different patterns and structure variations, as well as its implications during pain management in patients. A descriptive, observational, and morphometric study of patterns and structure variations of the lumbar plexus, intercostal nerves and pudendal nerve was conducted in 50 formalin-fixed cadaveric dissections of the Third Chair of Anatomy at the School of Medicine in the Universidad de Buenos Aires from August 2017 to December/2019. The standard description of the lumbar plexus was found in 35 cases; accessory femoral nerve was not present in any of the cases; absence of the iliohipogastric nerve was also not found in any case, while the accessory obturating nerve was found in 2 cases; genitofemoral nerve dividing within the muscle mass of psoas in 6 cases; lateral femoral cutaneous nerve emerging only from the second lumbar root in 6 cases and finally, presence of a branch of the obturating nerve was found joining the lumbosacral trunk in one case. The pudendal and intercostal nerve patterns presented a typical pathway in all cases. Adequate knowledge and description of the lumbar plexus, intercostal nerves and pudendal nerve is essential for an adequate approach of the abdominal-pelvic cavity in nerve blocks.