The pudendal syndrome: A photo essay of nerve compression damage visualized at neurolysis in patients with chronic neuropathic pelvic pain.

AIMS: (1) To use intraoperative photographs to visualize and explain pudendal nerve compressions and anatomical variations of compression sites in patients with chronic pelvic pain. (2) To emphasize the diagnostic importance of sensory examination with a safety pin at the six pudendal nerve branches in all patients with chronic pelvic pain; the dorsal nerves (penis or clitoris; the perineal nerves; and the inferior rectal nerves). METHODS: Between 2003 and 2014, "definite" pudendal neuropathy was diagnosed by examination and with two neurophysiologic tests. Neurolysis, via a transgluteal approach, was recommended only after 14 weeks of conservative care failed to adequately improve symptoms and validated symptom scores. Photographs of surgical findings were culled for their educational impact. An illustration of each photo clarifies the surgical anatomy. RESULTS: The transgluteal incision permits access to pudendal anatomy and compression sites from the subpiriformis area through the interligamentary space and the pudendal canal (Alcock canal). Compressions were acquired or congenital and severity varied significantly. Pinprick sensory testing diagnoses pudendal neuropathy in 92% of both genders. Mid-nerve compression occurred commonly between the sacrotuberous and sacrospinous ligaments less frequently in the Alcock canal, but also at aberrant pathways, for example, between layers of the sacrotuberous ligament; a separate inferior rectal nerve passing through the sacrospinous ligament; at an anomalous lateral pathway posterior to the ischial spine. The results of international surgeons are discussed. CONCLUSIONS: Decompression surgery was recommended in approximately 35% of patients in this practice, when pudendal neuropathy (pudendal syndrome), did not respond to two conservative levels of treatment: (1) nerve protection and medications and, (2) a series of three pudendal nerve perineural injections given at 4-week intervals. Significant nerve compression is consistently observed. Pathophysiology includes axonopathy from ischemia and demyelination. Neuropathy is readily diagnosed using a pinprick sensory examination of six pudendal nerve branches. Monitoring with the National Institutes of Health Chronic Prostatitis Symptom Index records cures >13 years.

Surgical approaches for pudendal nerve entrapment: insights from a systematic review and meta-analysis.

BACKGROUND: Pudendal nerve entrapment (PNE) is an underdiagnosed condition affecting a spectrum of pelvic functions, primarily pain, as outlined by Nantes diagnostic criteria. Although numerous surgical decompression techniques are available for its management, consensus on efficacy and safety is lacking. This study conducts a systematic review and meta-analysis to assess the efficacy and complication rates of the main surgical decompression techniques. METHODS: A comprehensive literature search was conducted in PubMed®, Embase®, Web of Science®, and ClinicalTrails.gov® on 19th of April 2023. Initial screening involved title and abstract evaluation, with subsequent retrieval and assessment of abstracts and full-text articles. Studies assessing pain outcomes before and after surgical release of the pudendal nerve were included. Studies without full-text, focusing on diagnostic methods or with outcomes relating solely to LUTS, digestive symptoms, or sexual dysfunction, were excluded. Risk of bias assessement was conducted using the National Institute of Health (NIH) Study Quality Assessment tool. Studies were categorized based on three surgical techniques: perineal, transgluteal, and laparoscopic transperitoneal. Random-effects meta-analysis with subgroup analysis were used. Meta-regression analyses were conducted to investigate the influence of covariates on the observed outcomes. RESULTS: Nineteen studies, comprising 810 patients, were included. The overall significant pain relief rate across all techniques was estimated at 0.67 (95% CI 0.54 to 0.78) with considerable heterogeneity (I2 = 80.4%). Subgroup analysis revealed success rate for different techniques: laparoscopic (0.91, 95% CI 0.64 to 0.98), perineal (0.69, 95% CI 0.52 to 0.82), and transgluteal (0.50, 95% CI 0.37 to 0.63). The laparoscopic technique exhibited a complication rate of 16.0%. Meta-regression indicated that patient age and median follow-up significantly influenced outcomes. CONCLUSION: While comparing surgical techniques is challenging, this meta-analysis highlights important outcome differences. The laparoscopic technique appears most promising for pain improvement. However, the study also emphasizes the need for further robust, long-term research due to significant heterogeneity across studies and prevelent risk of bias. PROSPERO database: CRD42023496564.

Cadaveric Insights into Pudendal Nerve Variations for Sacrospinous Ligament Fixation: A Case Series.

INTRODUCTION AND HYPOTHESIS: The proximity of the pudendal nerve to the sacrospinous ligaments (SSLs) can lead to serious complications during sacrospinous ligament fixation (SSLF). This case series is aimed at providing an overview of the anatomy of the pudendal nerve, including insights from cadaver dissections and discussions on rare variations observed during these dissections. METHODS: Dissections were conducted on five female cadavers using a posterior gluteal approach on both sides. The course, morphometric features and variations in the branches of the pudendal nerve were assessed at the level of the SSL and within the pudendal canal. RESULTS: The number of pudendal trunks cranial to the SSL ranged from one to three, with double trunks being the most common (70%). In 2 out of 10 (20%) sides inferior rectal nerves (IRNs) pierced through the SSL. In Case 1, IRNs pierced the SSL bilaterally before entering the pudendal canal and exiting at distances of 23.81 mm and 41.18 mm from the ischial spine on the right and left sides respectively. In Case 2, nerves with a width of 2.12 mm and 2.49 mm pierced the SSL and joined the IRN, piercing the SSL at 13.38 mm and 12.55 medial to the ischial spine and 16.80 mm and 19.32 mm lateral to the sacrum, on the left and right sides respectively. In 60% of cases, the IRN entered the pudendal canal, exiting at a median distance of 21.25 mm from the ischial spine. CONCLUSIONS: We identified significant variations in the number of trunks and branching patterns of the pudendal nerve around the SSL and the course of the IRN caudal to the SSL. We documented IRNs or nerves joining the IRNs piercing the SSL. Identifying these variations is crucial for surgeons to minimize the risk of pudendal nerve injury during SSLF.

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.

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 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.

Pathways and parameters of sacral neuromodulation in rats.

The stimulation paradigm for sacral neuromodulation has remained largely unchanged since its inception. We sought to determine, in rats, whether stimulation-induced increases in bladder capacity correlated with the proportion of sensory pudendal (PudS) neurons at each stimulated location (L6, S1). If supported, this finding could guide the choice of stimulation side (left/right) and level (S2, S3, S4) in humans. Unexpectedly, we observed that acute stimulation at clinically relevant (low) amplitudes [1-1.5 × motor threshold (Tm)], did not increase bladder capacity, regardless of stimulus location (L6 or S1). More importantly for the ability to test our hypothesis, there was little anatomic variation, and S1 infrequently contributed nerve fibers to the PudS nerve. During mapping studies we noticed that large increases in PudS nerve activation occurred at amplitudes exceeding 2Tm. Thus, additional cystometric studies were conducted, this time with stimulation of the L6-S1 trunk, to examine further the relationship between stimulation amplitude and cystometric parameters. Stimulation at 1Tm to 6Tm evoked increases in bladder capacity and decreases in voiding efficiency that mirrored those produced by PudS nerve stimulation. Many animal studies involving electrical stimulation of nerves of the lower urinary tract use stimulation amplitudes that exceed those used clinically (∼1Tm). Our results confirm that high amplitudes generate immediate changes in cystometric parameters; however, the relationship to low-amplitude chronic stimulation in humans remains unclear. Additional studies are needed to understand changes that occur with chronic stimulation, how these changes relate to therapeutic outcomes, and the contribution of specific nerve fibers to these changes.NEW & NOTEWORTHY Acute low-amplitude electrical stimulation of sacral nerve (sacral neuromodulation) did not increase bladder capacity in anesthetized CD, obese-prone, or obese-resistant rats. Increasing stimulation amplitude correlated with increases in bladder capacity and pudendal sensory nerve recruitment. It is unclear how the high-amplitude acute stimulation that is commonly used in animal experiments to generate immediate effects compares mechanistically to the chronic low-amplitude stimulation used clinically.

Characterizing the innervation of the vulvar vestibule and the immunohistochemical features of neuroproliferative vestibulodynia.

BACKGROUND: Provoked vestibulodynia (PVD) is a chronic pain condition characterized by allodynia localized to the vulvar vestibule. The finding of increased densities of nerve fibers in the vestibular mucosa of patients with PVD has led to the identification of a neuroproliferative subtype. The etiology of PVD, including neuroproliferative vestibulodynia (NPV), is not fully understood. The gross and microscopic innervation of the vulvar vestibule remains incompletely described, despite the preliminary data supporting the role of peripheral innervation in PVD. AIM: To characterize the gross anatomic and microscopic innervation of the vulvar vestibule through cadaveric dissection and immunohistochemistry. METHODS: The pudendal nerve and inferior hypogastric plexus (IHP) were dissected using 6 cadaveric donors. Histology and immunohistochemistry were used to confirm patterns of innervation identified gross anatomically. Immunohistochemistry was performed on vestibulectomy specimens obtained from 6 patients diagnosed with NPV and compared with cadaveric vestibular tissues. OUTCOMES: Outcomes included (1) dissection of pelvic innervation and (2) immunohistochemical localization of markers for the following: general innervation protein gene product 9.5 (PGP9.5), sensory innervation (calcitonin gene-related peptide), autonomic innervation (vasoactive intestinal polypeptide, tyrosine hydroxylase), neuroproliferation (nerve growth factor [NGF]), and immune activation (C-kit). RESULTS: Perineal (pudendal) nerve branches were traced to the external wall of the vulvar vestibule. Some anatomic heterogeneity was observed in perineal nerve-branching patterns. Fibers from the IHP were identified in close proximity to the vulvar vestibule. Autonomic and sensory nerve fibers were identified in both patient and cadaveric vulvar vestibule samples. Patient samples were characterized by the proliferation of PGP9.5-positive nerve fibers and C-kit-positive mast cells, which were in proximity to neve bundles and showed coexpression with putative NGF-positive cells. NGF expression was localized to a subset of nerves, including those that demonstrated co-expression of sensory and autonomic nerve markers. Increased densities of autonomic fibers positive for vasoactive intestinal polypeptide and tyrosine hydroxylase were observed in 1 patient sample. CLINICAL TRANSLATION: Heterogeneity in gross and microscopic patterns of innervation could explain variability in clinical response to treatment and should be used to inform future therapeutic interventions. STRENGTHS AND LIMITATIONS: This study used a combination of approaches to elucidate the innervation of the vulvar vestibule, including in NPV. The small sample size is a limitation. CONCLUSION: The vulvar vestibule contains both sensory and autonomic innervation, which may originate from the pudendal nerve and IHP. Our results support the existence of a neuroproliferative subtype that is characterized by the proliferation of sensory and autonomic nerve fibers and neuroimmune interactions.

Role of opioid and ß-adrenergic receptors in bladder underactivity induced by prolonged pudendal nerve stimulation in cats.

AIMS: To determine the role of opioid and ß-adrenergic receptors in bladder underactivity induced by prolonged pudendal nerve stimulation (PNS). METHODS: In α-chloralose anesthetized cats, 30-min PNS was applied repeatedly for 3-9 times to induce poststimulation or persistent bladder underactivity. Then, naloxone (opioid receptor antagonist, 1 mg/kg, IV) or propranolol (ß-adrenergic receptor antagonist, 3 mg/kg, IV) was given to reverse the bladder underactivity. After the drug treatment, an additional 30-min PNS was applied to counteract the drug effect. Repeated cystometrograms were performed by slowly (1-2 mL/min) infusing the bladder with saline via a urethral catheter to determine the bladder underactivity and the treatment effects. RESULTS: Prolonged (2-4.5 h) PNS induced bladder underactivity evident as a large bladder capacity (169 ± 49% of control) and a reduced amplitude of bladder contraction (59 ± 17% of control). Naloxone fully reversed the bladder underactivity by reducing bladder capacity to 113 ± 58% and increasing the amplitude of bladder contraction to 104 ± 34%. After administration of naloxone an additional 30-min PNS temporarily increased the bladder capacity to the underactive bladder level (193 ± 74%) without changing the amplitude of the bladder contraction. Propranolol had no effect on bladder underactivity. CONCLUSIONS: A tonic enkephalinergic inhibitory mechanism in the CNS plays a critical role in the bladder underactivity induced by prolonged PNS, while the peripheral ß-adrenergic receptor mechanism in the detrusor is not involved. This study provides basic science evidence consistent with the clinical observation that comorbid opioid usage may contribute to voiding dysfunction in patients with Fowler's syndrome.

Can we improve techniques and patients' selection for nerve stimulation suitable for lower urinary tract dysfunctions? ICI-RS 2023.

AIMS: Lower urinary tract dysfunctions (LUTD) are very common and, importantly, affect patients' quality of life (QoL). LUTD can range from urinary retention to urgency incontinence and includes a variety of symptoms. Nerve stimulation (NS) is an accepted widespread treatment with documented success for LUTD and is used widely. The aim of this review is to report the results of the discussion about how to improve the outcomes of NS for LUTD treatment. METHODS: During its 2023 meeting in Bristol, the International Consultation on Incontinence Research Society discussed a literature review, and there was an expert consensus discussion focused on the emerging awareness of NS suitable for LUTD. RESULTS: The consensus discussed how to improve techniques and patients' selection in NS, and high-priority research questions were identified. CONCLUSIONS: Technique improvement, device programming, and patient selection are the goals of the current approach to NS. The conditional nerve stimulation with minimally invasive wireless systems and tailored algorithms hold promise for improving NS for LUTD, particularly for patients with neurogenic bladder who represent the new extended population to be treated.

First case-series of robot-assisted pudendal nerve release: technique and outcomes.

OBJECTIVE: Pudendal Nerve Entrapment (PNE) may determine chronic pelvic pain associated with symptoms related to its innervation area. This study aimed to present the technique and report the outcomes of the first series of robot-assisted pudendal nerve release (RPNR). PATIENTS AND METHODS: 32 patients, who were treated with RPNR in our centre between January 2016 and July 2021, were recruited. Following the medial umbilical ligament identification, the space between this ligament and the ipsilateral external iliac pedicle is progressively dissected to identify the obturator nerve. The dissection medial to this nerve identifies the obturator vein and the arcus tendinous of the levator ani, which is cranially inserted into the ischial spine. Following the cold incision of the coccygeous muscle at the level of the spine, the sacrospinous ligament is identified and incised. The pudendal trunk (vessels and nerve) is visualized, freed from the ischial spine and medially transposed. RESULTS: The Median duration of symptoms was 7 (5, 5-9) years. The median operative time was 74 (65-83) minutes. The median length of stay was 1 (1-2) days. There was only a minor complication. At 3 and 6 months after surgery, a statistically significant pain reduction has been encountered. Furthermore, the Pearson correlation coefficient reported a negative relationship between the duration of pain and the improvement in NPRS score, - 0.81 (p = 0.01). CONCLUSIONS: RPNR is a safe and effective approach for the pain resolution caused by PNE. Timely nerve decompression is suggested to enhance outcomes.

Pudendal, but not tibial, nerve stimulation modulates vulvar blood perfusion in anesthetized rodents.

INTRODUCTION AND HYPOTHESIS: Preclinical studies have shown that neuromodulation can increase vaginal blood perfusion, but the effect on vulvar blood perfusion is unknown. We hypothesized that pudendal and tibial nerve stimulation could evoke an increase in vulvar blood perfusion. METHODS: We used female Sprague-Dawley rats for non-survival procedures under urethane anesthesia. We measured perineal blood perfusion in response to 20-minute periods of pudendal and tibial nerve stimulation using laser speckle contrast imaging (LSCI). After a thoracic-level spinalization and a rest period, we repeated each stimulation trial. We calculated average blood perfusion before, during, and after stimulation for three perineal regions (vulva, anus, and inner thigh), for each nerve target and spinal cord condition. RESULTS: We observed a significant increase in vulvar, anal, and inner thigh blood perfusion during pudendal nerve stimulation in spinally intact and spinalized rats. Tibial nerve stimulation had no effect on perineal blood perfusion for both spinally intact and spinalized rats. CONCLUSIONS: This is the first study to examine vulvar hemodynamics with LSCI in response to nerve stimulation. This study demonstrates that pudendal nerve stimulation modulates vulvar blood perfusion, indicating the potential of pudendal neuromodulation to improve genital blood flow as a treatment for women with sexual dysfunction. This study provides further support for neuromodulation as a treatment for women with sexual arousal disorders. Studies in unanesthetized animal models of genital arousal disorders are needed to obtain further insights into the mechanisms of neural control over genital hemodynamics.

The anatomy of the sacrospinous ligament: how to avoid complications related to the sacrospinous fixation procedure for treatment of pelvic organ prolapse.

INTRODUCTION AND HYPOTHESIS: Historically, the sacrospinous ligament (SSL) has been used to treat POP in order to restore the apical compartment through a posterior or an anterior vaginal approach. The SSL is located in a complex anatomical region, rich in neurovascular structures that must be avoided to reduce complications such as acute hemorrhage or chronic pelvic pain. The aim of this three-dimensional (3D) video describing the SSL anatomy is to show the anatomical concerns related to the dissection and the suture of this ligament. METHODS: We conducted a research of anatomical articles about vascular and nerve structures located in the SSL region, in order to increase the anatomical knowledge and show the best placement of sutures to reduce complications related to SSL suspension procedures. RESULTS: We showed the medial part of the SSL to be most suitable for the placement of the suture during SSL fixation procedures, in order to avoid nerve and vessel injuries. However, nerves to the coccygeus and levator ani muscle can course on the medial part of the SSL, the portion of the SSL where we recommended to pass the suture. CONCLUSIONS: Knowledge of the SSL anatomy is crucial and during surgical training it is clearly indicated to stay far away (almost 2 cm) from the ischial spine to avoid nerve and vascular injuries.

Clinical usefulness of quantitative thermal sensory testing in the diagnosis and surgical treatment of women with pudendal neuropathy.

BACKGROUND: The aim of this study, conducted on women with pudendal neuropathy, was to evaluate the usefulness of quantitative thermal sensory testing (QTST) in the diagnosis, surgical management, and prognosis of the disease. METHODS: The study was conducted on 90 women with pudendal neuropathy. QTST in pudendal nerve sensory innervation territory was realized before and more than 24 months after operative pudendoscopy on most patients. Cold and warm thresholds were evaluated together with a search for qualitative anomalies. The diagnostic value of QTST was assessed by comparing baseline data with normative values previously derived from 41 presumably healthy women. The effect of operative pudendoscopy on thermal sensitivity was tested by comparing preoperative and postoperative measurements. Assessment of the long-term prognostic value of QTST was based on "surgical success" defined as a VAS pain level less than 4 at least 2 years after surgery. RESULTS: The existence of qualitative anomalies, like anesthesia, allodynia, dysesthesia, radiation, and dyslocalization, was clearly indicative of pudendal neuropathy. The presence of after sensation and "out of limit" values of skin temperature and cold detection threshold were also helpful for diagnosing the disease. Surgery reduced qualitative anomalies but had no positive effect on QTST thresholds. QTST measurements had no real prognostic value but other factors like constipation and abnormal perineal descent were predictive of surgical success. CONCLUSION: For women with pudendal neuropathy, QTST can be considered a useful, non-invasive tool in the diagnosis, and management of the disease, but it cannot predict satisfactorily long-term outcome of operative pudendoscopy.

Intrapartum pudendal nerve block analgesia and childbirth experience in primiparous women with vaginal birth: A cohort study.

BACKGROUND: A negative childbirth experience has short- and long-term consequences for both mother and child. This study aimed to investigate the association between intrapartum pudendal nerve block (PNB) analgesia and childbirth experience. METHODS: Primiparous women with a singleton cephalic vaginal live births at term at Oslo University Hospital from January 1, 2017, to June 1, 2019, were eligible for inclusion. The main outcome was total score on a childbirth experience questionnaire (range 1.0-4.0, higher score indicates better childbirth experience). An absolute risk difference of 0.10 was considered clinically relevant. Propensity score matching was used to adjust for differences in baseline characteristics between women with and without PNB. The analyses were stratified by spontaneous vs instrumental birth. Subanalyses of the questionnaire's domains (own capacity, professional support, perceived safety, and participation) were performed. RESULTS: Of 979 participating women, mean age was 32 years. Childbirth experience did not differ between women with and without PNB, either in spontaneous (absolute risk difference of the mean: -0.05, P value 0.36) or in instrumental birth (absolute risk difference of the mean: 0.03, P value 0.61). There were no statistically significant differences between PNB group scores for the separate domains. CONCLUSIONS: Women's childbirth experiences did not differ between birthing people with or without PNB, either in spontaneous or in instrumental births. The clinical implications of our study should be interpreted in light of the pain-relieving effects of PNB.PNB should be provided on clinical indication, including for individuals with severe labor pain.

Ultrasound-Guided Pudendal Nerve Block versus Ultrasound-Guided Dorsal Penile Nerve Block for Pediatric Distal Hypospadias Surgery.

INTRODUCTION: The primary aim of the study was to use the duration until the first postoperative analgesic requirement after two different block techniques to compare the analgesic effect. The secondary aims were to compare the two methods for postoperative Children's Hospital Eastern Ontario Pain Scale (CHEOPS) scores, complications, and parental satisfaction level. MATERIALS AND METHODS: This prospective, observational study was conducted with male patients aged 1-7 years in the ASA I-II group, who were scheduled for hypospadias surgery between November 2019 and April 2020. Ultrasound (US)-guided pudendal nerve block (PNB) or US-guided dorsal penile nerve block (DPNB) was administered under general anesthesia before the operation. Postoperative analgesic need, postoperative pain, complications, and parental satisfaction were noted. The STROBE checklist was followed for reporting. RESULTS: The study was conducted with 30 patients in total, divided into 15 patients receiving PNB and 15 patients receiving DPNB. The effective minimum block duration was longer in the pudendal group at 22.22 ± 0.61 h than in the DPNB group at 22.19 ± 0.57 h. Additional analgesic was required in 4 subjects in the pudendal group and 5 in the DPNB group. There was no statistically significant difference in terms of the variables between the two groups (p > 0.05). DISCUSSION: US-guided DPNB and PNB were shown to provide successful postoperative analgesia and to have similar effectiveness in pediatric patients undergoing hypospadias surgery in this first prospective study of its kind in the literature. CONCLUSIONS: US-guided DPNB and PNB have been demonstrated to provide effective, safe, and long-term postoperative analgesia in pediatric patients who have undergone hypospadias surgery. Parental satisfaction in both groups is positively influenced by the minimum postoperative analgesia requirement, the long-term analgesic effect, and the lack of any complications.

OnabotulinumtoxinA Injections for the Treatment of Myofascial Pelvic Pain: 12-Year Experience at a Tertiary Care Academic Center.

OBJECTIVE: The aim of this study was to highlight the safety of OnabotulinumtoxinA (BTA) injections, with or without concurrent pudendal nerve block, in treating women with myofascial pelvic pain (MFPP). DESIGN: This was a retrospective cohort study. SETTING: The review was conducted in a tertiary care academic center. Participants/Materials: We conducted a chart review of patients who were diagnosed with MFPP and treated with BTA with or without pudendal nerve block between January 2010 and February 2022. METHODS: BTA was injected transvaginally into the pelvic floor muscle group. The primary outcomes were adverse events after BTA injections, and the secondary outcome was the effect of concomitant pudendal nerve block at the time of BTA injections. RESULTS: The cohort included 182 patients; 103 (56.6%) received BTA injections with pudendal nerve block, and 79 (43.4%) received BTA alone. There were no significant demographic differences between the two groups. Post-treatment complications of BTA administration included worsening of pelvic pain (11.5%), constipation (6.6%), urinary tract infection (2.7%), urinary retention (3.8%), and fecal incontinence (2.7%). No statistical difference was noted in the number of phone calls, patient-initiated electronic messages, emergency room visits, or clinic visits for both groups within 30 days post-treatment. The mean number of total injections was 1.6 in the BTA-only group and 1.7 in the BTA with pudendal block group (p = 0.421). Median time to re-intervention with a second BTA injection was 6.0 months; 5.6 months in the BTA with pudendal block group; and 6.8 months in the BTA-only group, p = 0.46. There were 63 re-intervention events after BTA injections. LIMITATIONS: Limitations of our study include the retrospective design making it vulnerable to missing or incomplete data available for review. CONCLUSION: OnabotulinumtoxinA is beneficial in treating women with MFPP; with a duration of therapeutic effect of approximately 6 months. The use of a concurrent pudendal nerve block did not impact clinical outcomes.

Vaginal Lubrication and Pressure Increase Induced by Pudendal Nerve Stimulation in Cats.

BACKGROUND: Vaginal lubrication and contractions are among the top difficulties affecting sexual intercourse in women after spinal cord injury. AIM: This study aimed at determining if pudendal nerve stimulation (PNS) can improve vaginal lubrication and induce increases in vaginal pressure. METHODS: In anesthetized cats, a small piece of cotton was inserted into the vagina for 10 minutes with or without PNS to measure vaginal wetness by the weight increase of the vaginal cotton. Then, a small balloon catheter was inserted into the vagina to measure the pressure increase induced by PNS. Intensity response of the vagina to PNS (30 Hz, 0.2 ms, 5 seconds) was determined at 1-4 times of intensity threshold (T) for PNS to induce an observable vaginal pressure increase. Frequency response was determined at 2T intensity in a range of PNS frequencies (5-50 Hz). Finally, fatigue in vaginal pressure was determined by applying PNS (30 Hz, 2T) either continuously or intermittently (5 seconds on and 5 seconds off) for 4 minutes. OUTCOMES: The effectiveness of PNS in increasing vaginal wetness and pressure is evaluated. RESULTS: PNS significantly (P = .0327) increased the measurement of vaginal wetness from 15.8 ± 3.8 mg during control without stimulation to 32.4 ± 4.7 mg after stimulation. Vaginal pressure increased as PNS intensity or frequency increased. PNS (30 Hz, 2T) induced vaginal pressure increase ≥80% of the maximal response. Intermittent PNS induced significantly (P = .0354) smaller fatigue (45.6 ± 3.7%) in vaginal pressure than continuous PNS (69.1 ± 3.0%) during the 4-minute stimulation. CLINICAL TRANSLATION: This study raises the possibility of developing a novel pudendal neuromodulation device to improve female sexual function after spinal cord injury. STRENGTHS & LIMITATIONS: This study provides preclinical data supporting the development of a novel pudendal neuromodulation device. The limitation includes the lack of chemical analysis of the vaginal secretion. CONCLUSION: PNS can improve vaginal lubrication and induce increases in vaginal pressure. Chen J, Zhong Y, Wang J, et al. Vaginal Lubrication and Pressure Increase Induced by Pudendal Nerve Stimulation in Cats. J Sex Med 2022;19:1517-1523.

Pudendal Neuromodulation is Feasible and Effective After Pudendal Nerve Entrapment Surgery.

BACKGROUND: Patients with intractable pain in the pudendal nerve distribution may benefit from pudendal neuromodulation; however, some may have previously undergone pudendal nerve entrapment surgery (PNES), potentially altering nerve anatomy and function. AIM: We examined pudendal neuromodulation outcomes in patients with prior PNES. METHODS: Patients with a history of PNES and quadripolar, tined pudendal lead placement for urogenital pain were reviewed. Symptoms and outcomes were collected from existing medical records. OUTCOMES: Patients with pudendal neuromodulation and prior PNES were compared to patients with no prior PNES who had pudendal lead placement. RESULTS: Fifteen patients with a history of 1, 2, or 3 prior PNES (n = 13, 1, and 1, respectively) were evaluated. Most (10; 67%) were female, with bilateral pain (9; 60%), and symptoms of 5-26 years. After trialing the lead, bladder symptoms and pain were improved in 8 of 12 and 9 of 14 patients, respectively, and 80% of patients (12/15) underwent permanent generator implantation. When prior PNES patients were compared to those with no prior PNES (n = 43), gender (67% vs 77% female; P = .50) and age (median 63 vs 58 years; P = .80), were similar; however, BMI differed (mean 24 vs 29; P = .008) and a lower proportion (12/15; 80% vs 42/43; 98%; P = .049) had generator implantation. Importantly, median lead implant time (48 vs 50 minutes; P = .65) did not differ between the 2 groups. CLINICAL IMPLICATIONS: Pudendal neuromodulation has the potential to provide pain relief for a very difficult-to-treat population; furthermore, it does not appear that prior PNES surgery made lead placement significantly more challenging. STRENGTHS & LIMITATIONS: Study strengths include being a tertiary referral center for urogenital pain and having a single surgeon perform all procedures in a regimented way. Limitations include the retrospective study design, small sample size and various approaches to PN CONCLUSION: Chronic pudendal neuromodulation can be a viable option even after prior PNES. Kristen M. Meier, Patrick M. Vecellio, Kim A. Killinger, Judith A. Boura, Kenneth M. Peters. Pudendal Neuromodulation is Feasible and Effective After Pudendal Nerve Entrapment Surgery. J Sex Med 2022;19:995-1001.