Efficacy and Clinical Applicability of Impar Ganglion Block in the Treatment of Pudendal Neuralgia: A Systematic Review

Abstract

Background/Objectives: Pudendal neuralgia (PN) is a debilitating chronic pain condition resulting from injury, inflammation, or entrapment of the pudendal nerve. It significantly affects patients’ quality of life and poses challenges to treatment due to its complex etiology. Conventional therapies often provide limited or temporary relief. The impar ganglion block (IGB) has emerged as a potential intervention for managing refractory pelvic pain syndromes. This systematic review aimed to evaluate the clinical efficacy, safety, and applicability of IGB in treating patients with PN. Methods: This systematic review evaluates the efficacy and clinical applicability of IGBs in treating PN. Following PRISMA-P 2020 guidelines, a systematic search was conducted in PubMed/MEDLINE, Embase, LILACS, and Cochrane Library. Eligible studies included RCTs, observational studies, and case series assessing pain reduction and quality of life post-IGB. Non-neuropathic pelvic pain studies were excluded. The ROBVIS tool assessed the risk of bias. Results: Of 306 articles screened, 16 met eligibility criteria. Studies showed that the IGB provides significant pain relief, particularly for refractory cases. Image-guided techniques enhanced precision and reduced complications. Combination therapies with corticosteroids yielded longer-lasting analgesia. However, methodological inconsistencies and varied patient selection limited generalizability. Conclusions: The IGB is a minimally invasive, effective option for managing PN. Further high-quality RCTs are needed to standardize protocols, optimize patient selection, and evaluate long-term efficacy. A multidisciplinary approach remains essential.

1. Introduction

Pudendal neuralgia (PN) is a chronic pain syndrome caused by injury, inflammation, or compression of the pudendal nerve, which is responsible for the sensory and motor innervation of the perineal region. This condition can be debilitating and significantly impact a patient’s quality of life, causing severe pain while sitting, urinating, engaging in sexual activities, or performing simple daily tasks. Despite its severity, diagnosis is often delayed, as few healthcare professionals specifically investigate this neuralgia. As a result, clinical management is frequently inadequate and ineffective, leading to symptom exacerbation [1,2].

The pudendal nerve is the primary neural pathway responsible for the sensory, motor, and autonomic innervation of the perineum. It originates from the sacral region, specifically from the S2 to S4 segments of the spinal cord, extending through the pelvis. The perineum is the area between the testicles and the anus in men and between the vagina and the anus in women, playing a fundamental role in the control of sexual, urinary, and fecal functions. When the pudendal nerve is injured, it can result in the most chronic and disabling form of pelvic pain—PN [3].

Although PN has often been associated with nerve “entrapment” in Alcock’s canal, recent studies indicate that Alcock’s canal compression is only one of the potential causes of this syndrome. Regardless of the etiological factor, persistent chronic pain can have severe psychological and emotional consequences, including anxiety, depression, and impairments in social and sexual life [3].

Characterized by intense, burning, and persistent pain along the pudendal nerve pathway, PN is often misdiagnosed, leading to inadequate treatments. Patients with chronic pelvic or perineal pain who do not improve with standard therapy should be reevaluated for possible PN, as the treatment protocol is typically distinct and individualized [4].

In this context, there is a significant interaction between the impar ganglion and the pudendal nerve. The impar ganglion plays a crucial role in pain modulation and the autonomic regulation of pelvic structures. When there is nerve damage or irritation in the pelvic region, including the pudendal nerve, pain perception may be modulated through the impar ganglion.

The impar sympathetic ganglion block emerges as a promising therapeutic alternative for managing chronic pelvic pain, including PN. Located at the midline of the sacrococcygeal region, the impar ganglion is a fundamental structure in the nociceptive transmission of the pelvis and perineum, making it a strategic target for pain blocking in both malignant and non-malignant conditions [5].

Studies suggest that the impar ganglion blockade can provide rapid and long-lasting pain relief, particularly in patients who do not respond to conventional approaches such as analgesics and tricyclic antidepressants. In addition to being a minimally invasive procedure, it enables the effective control of neuropathic and sympathetically mediated pain, improving functionality and quality of life [6].

Despite advances in chronic pelvic pain management, there are still gaps in the literature regarding the clinical applicability of the impar ganglion blockade for the treatment of PN. To address the clinical uncertainty surrounding the efficacy of the IGB for managing chronic pelvic pain syndromes, particularly in cases involving PN, we conducted a systematic review following the PRISMA guidelines. We included original clinical studies that explicitly evaluated the therapeutic use of IGBs in patients diagnosed with chronic pelvic pain, excluding case reports, reviews, animal studies, and articles where the intervention was not clearly defined or was combined with other primary therapeutic modalities. Two independent reviewers screened all the titles and abstracts, assessed full-text articles for eligibility, and extracted relevant data concerning patient characteristics, intervention details, follow-up duration, outcomes, and adverse events. The risk of bias was assessed using an adapted tool for observational studies. Our goal was to provide a critical synthesis of the available evidence, highlighting both the clinical potential and limitations of this interventional technique. By summarizing the characteristics and findings of the included studies, we aimed to inform future research directions, identify gaps in the literature, and discuss the need for standardized protocols and larger, high-quality randomized controlled trials to better understand the role of IGBs in the treatment of refractory pelvic pain.

2. Materials and Methods

This systematic review followed the PRISMA-P 2020 methodology. The participants included in this review were adults (aged 18 years and older) diagnosed with PN. The intervention consisted of the administration of a ganglion impar block with different anesthetic and corticosteroid substances, with control groups including placebo, conventional neuropathic pain treatments, or no treatment. The primary outcome assessed in this review was pain reduction, measured using validated scales such as the Visual Analog Scale (VAS) and the Brief Pain Inventory (BPI), along with quality of life and the safety of the procedure.

2.1. Inclusion Criteria

Adult participants (aged 18 years or older) diagnosed with PN; IGBs performed as a primary intervention; randomized controlled trials (RCTs), observational studies, and case series reporting quantitative results related to pain relief, functionality, or quality of life; studies published in English or Portuguese; specifically for inclusion in the final qualitative synthesis, the availability of clarifying information through direct communication with the study authors when essential methodological or clinical data were not clearly reported in the article.

2.2. Exclusion Criteria

Studies that did not specifically address the use of the ganglion impar block for treating PN; systematic reviews, editorials, and letters without original data; studies with pediatric populations or unrelated medical conditions; studies with inadequate methodology or unclear results.

2.3. Search Strategy

The initial screening of studies was based on the titles and abstracts obtained from multiple databases, including LILACS, Cochrane Library, PubMed/MEDLINE, and ScienceDirect, using a detailed search strategy. For example, the search strategy used in PubMed was as follows: (“Ganglion Impar Block” [MeSH Terms] OR “Ganglion Impar Injection”) AND (“Pudendal Neuralgia” [MeSH Terms] OR “Chronic Pelvic Pain”).

Relevant studies were selected by two independent reviewers using the Rayyan system to facilitate screening and selection. Discrepancies were resolved through discussions with a third reviewer to ensure impartiality.

2.4. Study Selection

After the main searches, duplicate articles were identified and removed using Mendeley Desktop. The titles and abstracts of articles were systematically and independently evaluated by two reviewers. Relevant articles were then fully reviewed based on eligibility criteria. When relevant information was not fully described, the authors of these studies were contacted for clarification.

2.5. Data Extraction

Two authors independently selected studies by screening titles and abstracts, followed by full-text screening. Any discrepancies were resolved by discussion until a consensus was reached. The following data were extracted: first author, year of publication, country, inclusion and exclusion criteria, sample size, participants’ characteristics (such as age, gender, sample size), study design, details of the interventions, outcome measurements, and outcomes. Data extraction was conducted systematically using a standardized form, capturing information such as the following: study design (randomized, observational, interventional, etc.); demographic characteristics of participants (age, sex, duration of neuralgia); details of the ganglion impar block procedure (substances used, administration technique, use of imaging guidance); primary outcomes (pain reduction assessed through VAS, BPI, and SF-36); secondary outcomes (quality of life, safety, and adverse effects). Extracted data were organized and analyzed using Rayyan to facilitate the systematic synthesis of the evidence.

2.6. Data Synthesis

The synthesis of the results was structured around key themes identified in the reviewed studies. The analysis considered variations in the following:

The type of anesthetic and corticosteroid substances used;

Duration of pain relief following the block;

Differences between image-guided and non-image-guided techniques;

Occurrence of adverse effects and complications.

2.7. Risk of Bias and Quality Assessment

The level of bias was assessed using the Cochrane Collaboration Risk of Bias criteria. For each of these risk domains, studies were categorized as low, uncertain, or high risk of bias based on random sequence generation, allocation concealment, the blinding of participants and personnel, the blinding of outcome assessment, incomplete outcome data, selective outcome reporting, and other biases.

The risk of bias was evaluated using Cochrane’s Risk of Bias in Non-Randomized Studies—of Interventions (ROBINS-I) tool. Figures representing bias risk were created using the ROBVIS (Risk Of Bias Visualization) tool [7].

3. Results

3.1. Selection of Studies

From the search in the PubMed/MEDLINE and Embase databases, a total of 306 articles were obtained, with 284 articles from PubMed/MEDLINE and 22 articles from EMBASE. After removing 72 duplicate articles, a total of 241 articles remained.

After screening the titles and abstracts of all 241 articles, a total of 16 articles was selected, of which one was a poster and two were restricted from full-text access. The selected articles were then reviewed in full, and the absence of detailed information regarding various criteria was noted during the verification of inclusion criteria.

Of the sixteen authors contacted, responses were obtained for four articles. The author whose article corresponded to a poster was contacted to verify the existence of a corresponding study. After reviewing the articles with the data obtained from the contacted authors, four articles were included in this systematic review.

The PRISMA diagram shown in Figure 1 summarizes the article selection steps and the characteristics of the excluded studies.

3.2. Study Quality Assessment

Out of the 241 studies initially identified, 225 were excluded during the title and abstract screening phase as they were deemed irrelevant based on predefined inclusion and exclusion criteria. The term “irrelevant” refers to studies that did not investigate PN, did not assess IGBs as a therapeutic intervention, or were of an inappropriate design (e.g., animal studies, reviews, case reports, or technical notes). This strict screening process ensured that only studies directly assessing the clinical application of IGBs in PN patients were included in the final analysis. Ultimately, only four studies fulfilled all eligibility criteria and were included in the qualitative synthesis.

Due to significant clinical and methodological heterogeneity among the included studies—including differences in intervention protocols, outcome measures, and follow-up durations—a formal statistical analysis or meta-analysis was not feasible. Therefore, we opted for a qualitative and descriptive synthesis of the data.

A total of 353 patients were included across the four studies selected for qualitative synthesis. Kale et al. [8] evaluated 35 patients undergoing ultrasound-guided pudendal nerve infiltration. Labat et al. [9] reported outcomes from 201 patients treated with transsacrococcygeal IGBs. Antolak et al. [10] analyzed 51 patients receiving transvaginal pudendal nerve infiltration, while Vancaillie et al. [11] included 66 patients treated with fluoroscopy-guided nerve block techniques. These sample sizes formed the basis of the qualitative comparison presented in this review.

The methodological quality of the four selected studies was assessed based on their design, reporting clarity, and relevance to the central research question. Kale et al. [8] described the use of image-guided pudendal nerve blocks in a cohort of patients with PN, emphasizing the use of CT-guided techniques to ensure the accurate localization of the nerve. Their study reported positive outcomes in pain reduction, and they highlighted the importance of precise anatomical targeting to enhance therapeutic effects.

Labat et al. [9] showed the long-term efficacy of IGBs using a retrospective analysis of patients treated at a tertiary care center. The authors underscored the role of repeated blocks and multimodal approaches in managing complex pelvic pain syndromes. Their findings suggested that IGBs could provide substantial pain relief, particularly when integrated with other conservative treatments.

Antolak et al. [10] presented a case series detailing the diagnostic and therapeutic value of image-guided blocks in patients with suspected pudendal nerve entrapment. The study combined clinical and imaging criteria to identify suitable candidates and noted that the blocks were useful both as a diagnostic tool and as a therapeutic intervention, particularly in selecting patients for surgical decompression.

Vancaillie et al. [11] suggested that pudendal nerve blocks performed under image guidance could serve as both a stand-alone treatment and as part of a multidisciplinary management plan for chronic pelvic pain. They discussed patient selection strategies and noted the need for consistent diagnostic criteria to improve treatment outcomes and comparability across studies.

A summary of study design, patient characteristics, sample size, interventions, outcome assessments, and findings is listed in

Table 1. Study characteristics of the included studies.

Study	Design/N	Population (Mean Age ± SD/Range)	Technique and Imaging Guidance	Interventions	Drugs and Dosages Used	Outcome Measures	Follow-up and Outcome Durability	Results
Kale et al. [8]	Comparative study, N = 35	Patients with PN. Mean age: 37.3 ± 10 years.	Ultrasound-guided transgluteal approach	Ultrasound-guided transgluteal (TG-PNI) vs. finger-guided transvaginal pudendal nerve block (TV-PNI)	8 mL of 0.5% bupivacaine + 2 mL of 8 mg of dexamethasone	Pain during/after intercourse, pain in the sitting position, and pain in the region from the anus to the clitoris	6-month follow-up; sustained pain relief in most patients	The TV-PNI may be an alternative to the US-guided technique as a safe, simple, effective approach in pudendal nerve blocks.
Labat et al. [9]	RCT, N = 201	Patients with PN. Mean age: 57 ± 12 years.	CT-guided transsacrococcygeal ganglion impar block	Pudendal nerve block with anesthetic alone vs. local anesthetic plus corticosteroid vs. anesthetic plus corticosteroid with a large volume of normal saline	4 mL of 1% lidocaine ± 20 mg of methylprednisolone	Pain relief (VAS), QoL, and sexual function	3-month follow-up; pain relief reported, recurrence not detailed	Steroid infiltrations do not improve the results of local anesthetic infiltrations in PN.
Antolak et al. [10]	Observational study, N = 51	Men with PN. Mean age: 50 ± 8 years.	Transvaginal digital guidance	Pudendal nerve perineural injections (PNPIs)	6 mL of 0.25% bupivacaine + 40 mg of methylprednisolone	Pain relief to a sensory pinprick and patient-reported pain level	2 h follow-up; immediate relief only	A single PNPI results in complete pain control in approximately 40 to 85% of patients.
Vancaillie et al. [11]	Prospective, single-arm, open-label study, N = 66	Women with PN. Mean age: 45.02 ± 14.32 years.	Fluoroscopy-guided impar ganglion block	Response to pudendal nerve block	5 mL of 0.5% levobupivacaine (no corticosteroid)	Pain relief and pelvic floor symptoms	64 h follow-up; short-term relief observed	Significant pain relief and improvement in pelvic floor symptoms in 86.9% patients.

.

3.3. Risk of Bias

The risk of bias for the four selected studies was assessed using a simplified domain-based approach adapted from the Cochrane risk of bias tool (ROBVIS, Risk of Bias Visualization), focusing on key elements such as selection bias, performance bias, detection bias, attrition bias, and reporting bias. As illustrated in Figure 2, most studies presented a low risk of bias in reporting and detection domains, suggesting that outcomes were clearly described and based on relevant clinical criteria. However, moderate to high risk was noted in the selection and performance domains, primarily due to non-randomized designs and a lack of blinding. One study showed an unclear risk in terms of attrition due to the incomplete reporting of follow-up data. It is important to note that due to the heterogeneity of study designs and the absence of pre-registered protocols, certain studies, such as Vancaillie et al. [11], demonstrated a high risk of bias, particularly in the domain related to selective reporting. While this limitation affects the ability to perform a quantitative comparison or draw strong conclusions, the qualitative risk of bias analysis still provides meaningful insights into the reliability and transparency of reported outcomes. Overall, the figure highlights methodological limitations that should be considered when interpreting the results, reinforcing the need for future randomized controlled trials with a more robust design.

4. Discussion

The findings of this systematic review highlight the clinical relevance of the IGB as a promising interventional technique for the management of PN, a complex and often refractory cause of chronic pelvic pain. Although the number of studies included in this review was limited, the available evidence suggests that impar ganglion can provide significant pain relief, particularly when incorporated into a multimodal management strategy.

Each of the four included studies emphasized different aspects of the procedure, offering complementary perspectives on efficacy, technique, and patient outcomes. Kale et al. [8] compared ultrasound-guided transgluteal pudendal nerve infiltration (TG-PNI) with finger-guided transvaginal pudendal nerve infiltration (TV-PNI), demonstrating similar outcomes in pain reduction. The study highlights the importance of individualized anatomical approaches and suggests that ultrasound guidance enhances procedural accuracy while remaining non-invasive. Labat et al. [9] focused on the long-term effects of repeated pudendal nerve blocks and showed that sustained pain relief could be achieved through serial interventions. Their work supports the concept of using IGBs as part of a broader therapeutic sequence rather than a one-time procedure. Antolak et al. [10] investigated the diagnostic and therapeutic value of pudendal nerve blocks and suggested that an early procedural response could help stratify patients for surgical interventions. However, this study emphasized short-term outcomes and did not assess the durability of relief. Vancaillie et al. [11] underlined the need for a multidisciplinary approach, integrating IGBs with physical therapy and psychological support. They also addressed the limitations of monotherapy and the potential for transient pain relief, which may require adjunctive strategies. Despite methodological differences, all studies support the utility of IGBs in reducing pain intensity and improving quality of life in patients with PN. However, limitations such as small sample sizes, a lack of randomization, and the absence of control groups constrain the strength of their conclusions.

PN is a debilitating condition characterized by chronic pelvic pain resulting from the entrapment or irritation of the pudendal nerve. This nerve, which innervates the perineum, external genitalia, and anus, plays a crucial role in both sensory and motor functions within the pelvic region. The complex anatomy and deep location of the pudendal nerve pose significant challenges in both diagnosis and treatment. Among various interventional techniques, pudendal nerve blocks (PNBs) and ganglion impar blocks (IGBs) have emerged as prominent strategies for managing PN [12]. Chronic pelvic pain, particularly when associated with PN, remains a complex and challenging condition to manage, requiring multimodal treatment strategies [13]. The impar ganglion has been recognized as a key structure in the modulation of pelvic pain, and its blockade has demonstrated promising results in various pain syndromes [5].

A crucial aspect of this review is the comparison between different approaches for nerve block techniques. Studies such as those by Kale et al. [8] and Vancaillie et al. [11] have compared ultrasound-guided transgluteal pudendal nerve infiltration (TG-PNI) with finger-guided transvaginal pudendal nerve infiltration (TV-PNI), showing comparable effectiveness in pain relief. No statistically significant difference in success rates between the two methods was found, suggesting that both techniques can be effectively employed based on clinician expertise and patient-specific factors. However, the study noted that TV-PNBs might be more accessible in settings lacking advanced imaging modalities, while TG-PNBs offer the advantage of real-time visualization, potentially reducing complication rates.

Among the four included studies, all of them used a combination of local anesthetics and, in some cases, corticosteroids for the IGB, though the exact agents and dosages varied. Kale et al. [8] used a mixture of local anesthetic (8 mL of 0.5% bupivacaine) and corticosteroid (2 mL containing 8 mg dantrolene). Labat et al. [9] used 4 mL of 1% lidocaine, with or without the addition of 20 mg of methylprednisolone. Antolak et al. [10] used 6 mL of 0.25% bupivacaine combined with 40 mg of methylprednisolone. Vancaillie et al. [11] used 5 mL of 0.5% levobupivacaine without corticosteroids. While the majority of the studies combined a local anesthetic with a corticosteroid, the specific drug types and concentrations were not consistent across studies. This pharmacological heterogeneity may influence both the magnitude and duration of the analgesic effects, complicating the direct comparison of the outcomes. For instance, the use of different corticosteroid potencies (e.g., methylprednisolone vs. dexamethasone) and variations in local anesthetic concentrations (e.g., bupivacaine vs. levobupivacaine vs. lidocaine) introduce variables that may alter block efficacy and safety profiles. These differences limit the feasibility of conducting meaningful comparative or pooled analyses and reinforce the need for standardized protocols in future clinical research.

The utilization of image-guided techniques has revolutionized the administration of PNBs, enhancing both precision and safety. Traditionally, PNBs were performed using anatomical landmarks, which often led to variability in success rates and an increased risk of complications. The advent of fluoroscopy and ultrasound (US) guidance has addressed these limitations by allowing the direct visualization of the pudendal nerve and surrounding structures. A randomized controlled trial by Hurdle et al. compared US-guided PNBs to fluoroscopy-guided techniques, revealing that while both methods achieved comparable success rates in nerve blocking, the US-guided approach required a longer procedural time. This finding underscores the learning curve associated with US-guided techniques but also highlights their potential for increased accuracy once proficiency is attained [14].

One of the major advantages of the IGB is its minimally invasive nature and its potential to provide prolonged pain relief. Studies have reported that IGBs using local anesthetics and corticosteroids can yield significant reductions in pain scores, even in cases that are refractory to conventional treatment [9]. This aligns with previous research indicating that a sympathetic blockade is a viable approach for neuropathic and sympathetically mediated pain [15].

Further supporting the efficacy of US-guided PNBs, a study by Bendtsen et al. [16] demonstrated that real-time US guidance allows for the identification of critical anatomical landmarks, such as the ischial spine and sacrospinous ligament, facilitating precise needle placement. The study reported significant pain relief in patients with chronic perineal pain, emphasizing the clinical utility of this approach. Additionally, the ability to visualize the internal pudendal artery using color Doppler reduces the risk of vascular injury, a notable advantage over blind or landmark-based techniques [17,18].

Despite its therapeutic potential, the literature still presents discrepancies regarding the long-term efficacy of IGBs for PN. Some reports suggest that repeated procedures may be necessary to maintain sustained pain relief [10], while others indicate a more transient benefit, necessitating combination therapies with pharmacological and physical rehabilitation interventions [11].

Another important consideration is the role of image guidance in nerve block procedures. Image-guided techniques, such as fluoroscopy and ultrasound, have been shown to improve precision and efficacy while minimizing the risks of complications, such as nerve injury and vascular puncture [8]. However, accessibility and cost effectiveness remain challenges in certain healthcare settings, particularly in low-resource environments [19].

Patient selection is another critical determinant of therapeutic success. Ideal candidates for PNBs and GIBs are those with well-defined neuropathic pain localized to the pudendal nerve distribution who have not responded adequately to conservative measures such as pharmacotherapy and physical therapy [20]. Comprehensive assessment, including detailed history, physical examination, and adjunctive diagnostic tools like nerve conduction studies, can aid in identifying patients who are most likely to benefit from these interventions [21]. Moreover, addressing psychosocial factors is essential, as chronic pelvic pain is often associated with psychological comorbidities that can influence treatment outcomes [22]. Psychosocial factors should also be considered when evaluating treatment outcomes. Chronic pain conditions, including PN, are often associated with psychological distress, anxiety, and depression, which can exacerbate pain perception and the treatment response [6]. Therefore, a comprehensive approach integrating pharmacological, interventional, and psychological therapies may enhance patient outcomes.

The findings of this systematic review align with previous research emphasizing the need for the multidisciplinary management of PN. As highlighted by Kim et al. [5], interventions targeting both nociceptive and neuropathic pain pathways may optimize patient recovery and functional improvement. Future studies should focus on larger-scale randomized controlled trials to establish standardized protocols for the impar ganglion blockade in this patient population.

Furthermore, the safety profile of the IGB remains a critical area of investigation. While adverse effects are generally mild and transient, including local discomfort and transient hypotension, rare but serious complications, such as infection and neuritis, have been documented [23]. The establishment of standardized procedural guidelines and patient selection criteria may mitigate these risks.

This review has several limitations. Due to the heterogeneity of the study designs, patient selection criteria, and outcome measures, a meta-analysis was not feasible, necessitating a narrative synthesis of the findings. Additionally, most of the included studies lacked standardized diagnostic criteria for PN, which may have influenced patient heterogeneity and treatment outcomes. Although only studies in which the IGB was the primary interventional therapy were included, it is possible that some patients received pharmacological treatment concurrently or prior to the procedure. The retrospective design of some studies and limited reporting on adjunctive therapies may have influenced the interpretation of the outcomes.

Another relevant limitation found among the included studies is the heterogeneity in the follow-up periods and the inconsistent reporting of the long-term outcomes, which significantly hampers the ability to assess sustained efficacy and safety. Kale et al. [8] followed patients for 6 months and reported prolonged pain relief based on VAS scores but did not detail recurrence or failure rates. Labat et al. [9] reported improvement over a 3-month follow-up yet similarly lacked explicit data on symptom recurrence or treatment failure. Antolak et al. [10] limited their analysis to a 2 h post-procedural observation, focusing solely on immediate outcomes, with no long-term data available. Vancaillie et al. [11] assessed patients over 64 h, also emphasizing short-term effects without extended follow-up. While all studies described some degree of pain relief following ganglion impar blockade, the absence of standardized follow-up protocols, recurrence tracking, and adverse event reporting weakens the strength of the evidence.

This review was not registered with PROSPERO, as the available literature did not provide sufficient diagnostic details to meet their registration requirements; however, the records of similar registered reviews were checked to avoid duplication. While our findings suggest that the IGB is an effective approach for managing PN, the absence of high-quality randomized controlled trials limits the strength of our conclusions. Future well-designed RCTs with standardized protocols and long-term follow-up are needed to further validate these findings.

Given the heterogeneity of the included studies and the variations in methodological quality, especially regarding diagnostic criteria, follow-up duration, and reporting transparency, the comparative analysis presented in this review is intended to be interpretative and exploratory rather than conclusive. While a formal meta-analysis was not feasible, the qualitative comparison allowed us to identify recurring patterns, procedural differences, and potential areas for clinical improvement. These findings should be interpreted with caution and underscore the urgent need for high-quality, prospective, and protocol-registered randomized controlled trials to establish standardized guidelines.

Furthermore, although sixteen studies met our inclusion criteria, the qualitative synthesis was restricted to four articles whose authors responded to our contact attempts. While this limits the breadth of insights gathered, our objective in this phase was to explore contextual details and practical considerations not explicitly reported in the manuscripts. These perspectives, while limited in number, offered valuable contributions to understanding how interventions were implemented in practice. We acknowledge that including data from all 16 studies could have enriched the analysis; however, the choice to engage directly with authors was intended to access nuanced, experience-based information that supports future research planning and transparency in reporting.

5. Conclusions

In conclusion, PNBs and GIBs represent valuable tools in the interventional management of PN, offering significant pain relief for appropriately selected patients. The integration of image guidance has enhanced the precision and safety of these procedures, though considerations regarding accessibility and training remain pertinent. A multimodal approach, encompassing interventional techniques, pharmacotherapy, physical therapy, and psychological support, is likely to yield the most favorable outcomes. Future research should focus on addressing current limitations through well-designed clinical trials to further elucidate the role of these interventions in the comprehensive care of patients with PN.