Anterior Cutaneous Nerve Entrapment Syndrome Research Articles

Long-Term Efficacy of Posterior Neurectomy in Anterior Cutaneous Nerve Entrapment Syndrome.

To analyze long-term treatment outcomes of a posterior neurectomy in a large cohort of patients with anterior cutaneous nerve entrapment syndrome (ACNES). The current step-up treatment approach for ACNES involves abdominal wall tender point injections, pulsed radiofrequency, and neurectomy. If an anterior neurectomy fails or pain reoccurs, a posterior neurectomy is considered as a final surgical option. Data on posterior neurectomy treatment outcomes are scarce. ACNES patients who underwent a unilateral posterior neurectomy between 2012 and 2022 in a single institution completed a questionnaire regarding their current pain status. Primary outcomes were short- and long-term treatment success, defined as ≥50% pain relief. Patients were stratified whether the operative indication was recurrent pain (>3months) after an initially successful anterior neurectomy or ongoing pain after an anterior neurectomy. Data from 260 of 379 patients (77% female, mean age 42years) were analyzed (68.6% response rate). Sensitivity analysis found that short-term outcomes were similar between responders and non-responders. The recurrent pain group demonstrated significantly better treatment outcomes compared to the ongoing pain group, both in the short-term (7weeks; treatment success 79.2% vs. 53.2%, p < 0.001) and long-term (58months; treatment success 61.1% vs. 42.0%, p = 0.001). Sixteen (minor) complications (6.2%) were reported, resulting in three surgical re-interventions (1.2%). A posterior neurectomy is long-term beneficial in approximately half of patients although treatment success is better for recurrent pain than ongoing pain. These findings aid in optimizing preoperative patient counseling.

A 26 years old primigravida woman presented with abdominal cutaneous entrapment syndrome: a case report

BackgroundAbdominal cutaneous nerve entrapment syndrome (ACNES) is characterized by severe, mostly refractory, chronic pain due to the entrapment of the cutaneous branches of the lower torso intercostal nerves at the lateral edge of the rectus abdominis muscle. ACNES is rare compared to other pregnancy-related peripheral neuropathies and is often overlooked as a differential diagnosis for abdominal pain, despite the diagnosis relying primarily on patient history and physical examination. Emergency physicians and other medical personnel’s lack of exposure to such cases results in unnecessary laboratory requests, repeated visits, and increased fear and tension for the patient.Case presentationA 26-year-old primigravida on her second trimester of pregnancy presented to our Emergency department with persistent localized right upper quadrant abdominal pain. Despite repeated visit to the nearby hospital, no diagnosis was settled and the pain persisted. At our ED after a thorough history, physical examination and diagnostic test no abnormality was found. Finally Abdominal cutaneous nerve entrapment syndrome (ACNES) was considered and a mixture of 1 ml 2% lidocaine with adrenaline and 1 ml dexamethasone (4 mg) was infiltrated into the fascial plane in a fanning fashion into the most tender area using a modified technique and the patient reported significant improvement in pain.ConclusionAbdominal cutaneous nerve entrapment syndrome (ACNES) is a cause of abdominal pain in pregnancy that is often overlooked. The objective of this study is to describe a rare case of ACNES in a 26-year-old primigravida woman who presented to a low-resource emergency department to assist patient management.

A positive scratch collapse test in anterior cutaneous nerve entrapment syndrome indicates its neuropathic character.

Chronic abdominal pain is occasionally caused by an abdominal wall entity such as anterior cutaneous nerve entrapment syndrome (ACNES). This syndrome is thought to occur due to intercostal nerve branches (T7-12) that are entrapped in the rectus abdominis muscles. The diagnosis is largely based on subjective clues in patient history and physical examination. A test referred to as the scratch collapse test (SCT) is used as an additional diagnostic tool in peripheral nerve entrapment syndromes such as the carpal tunnel syndrome. The aim of the present study is to investigate whether an SCT was positive in patients with suspected ACNES. If so, this finding may support its hypothesized neuropathic character. A prospective, case-control study was performed among patients with ACNES (n = 20) and two control groups without ACNES (acute intra-abdominal pathology n = 20; healthy n = 20), all were consecutively included. ACNES was diagnosed based on previously published criteria. The SCT test was executed at the painful abdominal area in both patient groups and at a corresponding area in healthy controls. Predictive values, sensitivity, and specificity were calculated. Videos of tests were evaluated by blinded observers. SCT was judged positive in 19 of 20 ACNES patients but not in any of the 40 controls. A 95% sensitivity (confidence interval [CI]: 75-99) and optimal specificity (100%; CI: 83-100) were calculated. The positive SCT supports the hypothesis that ACNES is an entrapment neuropathy. A positive SCT should be considered a major diagnostic criterion for ACNES.

A cross‐sectional study of anterior cutaneous nerve entrapment syndrome at a Japanese emergency department

AbstractBackgroundAnterior cutaneous nerve entrapment syndrome (ACNES) is the most common cause of abdominal wall pain. This study aimed to clarify the proportion of ACNES cases among those of abdominal pain and the clinical characteristics and prognosis of the disease in an emergency department (ED) of a Japanese general hospital.MethodsThe medical records of patients from January 2014 to December 2023 were reviewed, and patients aged 15 years or older with abdominal pain with positivity for Carnett's sign, a good response to trigger point injection (TPI), and an ACNES diagnosis were included. The proportion of ACNES cases among the complaints related to abdominal pain in the ED between 2020 and 2023 was then determined. The recurrence rate was also determined using data from the medical records and telephone follow‐ups.ResultsTwenty‐one patients were included. Their median age was 50 years (range: 16–83 years), 13 (62%) were female, and 11 (52%) had acute‐onset pain. Follow‐up data were available for 11 patients (52%), seven (64%) of whom had recurrent pain for a median period of 1 week after the index visit. The proportion of ACNES cases among those of abdominal pain was 0.11%.ConclusionACNES might be uncommon among patients with abdominal pain in the ED setting although underdiagnosis of this condition might have led to an underestimation of the proportion of cases. Moreover, given the high recurrence rate of abdominal pain associated with ACNES, following up these patients is very important.

Anterior cutaneous nerve entrapment syndrome (ACNES) in a Palliative care setting

Anterior cutaneous nerve entrapment syndrome (ACNES) in a Palliative care setting

POSITIVE SCRATCH COLLAPSE TEST IN ANTERIOR CUTANEOUS NERVE ENTRAPMENT SYNDROME (ACNES): EVIDENCE FOR A PERIPHERAL NEUROPATHY?

Abstract Background Chronic abdominal pain is occasionally caused by an abdominal wall entity such as Anterior Cutaneous Nerve Entrapment Syndrome (ACNES). This syndrome is thought to occur due to entrapped intercostal nerve branches (Th7-12) within the rectus abdominis muscles. This clinical diagnosis is based on subjective clues in patient history and physical examination. In contrast, in carpal tunnel syndrome an additional diagnostic test is used, which is referred to as the scratch collapse test (SCT). The SCT has shown positive results not only in other peripheral entrapment neuropathies involving the ulnar, peroneal, and long thoracic nerve, but also in three recently described ACNES patients. We investigated whether the SCT is of diagnostic use in patients suspected of having ACNES. Method A prospective, case-control study was performed among patients with ACNES (n = 20) and two control groups without ACNES (acute abdomen n = 20; healthy n = 20), all were consecutively included. ACNES was diagnosed based on previously published criteria. The SCT test was executed at the painful abdominal area in both patient groups and at a corresponding area in healthy controls. Predictive values, sensitivity, and specificity were calculated. Videos of tests were evaluated by blinded observers. Results SCT was judged positive in 19 of 20 ACNES patients, but not in any of the 40 controls. A 95% sensitivity (CI:75–99) and 100% specificity (CI: 83–100) were calculated. Conclusion This study provides strong evidence that ACNES should be considered as an entrapment neuropathy, while a positive SCT should be considered as a major diagnostic criterion.

VISCERAL SYMPTOMS IN ABDOMINAL WALL PAIN

Abstract Purpose Anterior Cutaneous Nerve Entrapment Syndrome (ACNES) is characterized by neuropathic pain in a predictable, circumscript abdominal area. The diagnostic delay is long, with half of ACNES-affected individuals reporting next to pain, also nausea, bloating, or loss of appetite mimicking some kind of visceral disease. The aim of this study was to describe these phenomena and to determine whether treatment could successfully reverse the visceral symptoms. Methods This was a prospective observational study. Adult patients who fulfilled published criteria for ACNES and reported at least one visceral symptom at intake were eligible for the study. A self-developed Visceral Complaints ACNES Score (VICAS) questionnaire that scores several visceral symptoms (minimum 1 point, maximum 9 points) was completed before and after therapy. The success of treatment was defined as at least 50% reduction in pain. Results Data from 100 selected (at least one visceral symptom) patients (86 females) aged 39 ± 5 years were available for analysis. Frequently reported symptoms were abdominal bloating (78%), nausea (66%) and altered defecation (50%). Successful pain treatment significantly reduced the number of visceral symptoms, with a VICAS before of 3 (range 1–8) and after of 1 (range: 0–6) (p &amp;lt; 0.001). A low baseline VICAS was associated with successful treatment outcome (OR: 0.738, 95% CI: 0.546–0.999). Conclusion Patients with ACNES may report a variety of visceral symptoms. Successful treatment substantially reduces these visceral symptoms in selected patients, indicating a segmental relation between the abdominal wall and the viscera.

Lidocaine patch as noninvasive alternative treatment option in children with anterior cutaneous nerve entrapment syndrome: A retrospective case series.

Chronic abdominal pain in children is occasionally caused by anterior cutaneous nerve entrapment syndrome (ACNES). Diagnosing and treating this typical peripheral abdominal wall neuropathy is challenging. Management usually starts with minimally invasive tender point injections. Nevertheless, these injections can be burdensome and might even be refused by children or their parents. However, a surgical neurectomy is far more invasive. Treatment with a Lidocaine 5% medicated patch is successfully used in a variety of peripheral neuropathies. This single center retrospective case series aimed to evaluate the effectiveness and tolerability of lidocaine patches in children with ACNES. Children aged under 18 diagnosed with ACNES who were treated with a 10 day lidocaine patch treatment between December 2021 and December 2022 were studied. Patient record files were used to collect treatment outcomes including pain reduction based on NRS and complications. Twelve of sixteen children (mean age 13 years; F:M ratio 3:1) diagnosed with ACNES started the lidocaine patch treatment. Two patients achieved a pain free status and remained pain free during a 4 and 7 months follow-up. A third child reported a lasting pain reduction, but discontinued treatment due to a temporary local skin rash. Five additional patients reported pain reduction only during application of the patch. The remaining four children experienced no pain relief. No adverse effects were reported. Lidocaine patches provides pain relief in a substantial portion of children with ACNES.

Precision Trigger Point Injections: An Anatomically Guided Approach for Anterior Cutaneous Nerve Entrapment Syndrome Treatment.

Precision Trigger Point Injections: An Anatomically Guided Approach for Anterior Cutaneous Nerve Entrapment Syndrome Treatment.

How Do We Treat Children with Anterior Cutaneous Nerve Entrapment Syndrome and Is the Biopsychosocial Model Also Being Applied? A Scoping Review.

Evidence-based guidelines for managing anterior cutaneous nerve entrapment syndrome (ACNES) in children are absent. The primary aim of this review was to scrutinize the evidence supporting currently used treatment interventions. In accordance with the World Health Organization (WHO) guidelines for managing chronic pain in children, these patients and their families and caregivers should be treated within the context of the biopsychosocial model; pain should not be treated purely as a biomedical problem. Therefore, our second aim was to evaluate whether these interventions are applied within the context of the biopsychosocial model, utilizing an inter- or multidisciplinary approach. A scoping review of the literature was conducted to explore treatment strategies for ACNES in children. To ensure a comprehensive overview of published literature on this topic, the search was not restricted based on study type. Two reviewers independently assessed titles and abstracts. After excluding records unrelated to children, full texts were screened for inclusion. Any discrepancies in judgement were resolved through discussion with a third reviewer. Out of 35 relevant titles, 22 were included in this review. Only 4 articles provided information on long-term outcomes. The overall quality of the review was deemed low. The majority of reports did not address treatment or education within the psychological and social domains. A structural qualitative analysis was not feasible due to the substantial heterogeneity of the data. The evidence supporting current treatment strategies in children with ACNES is of low quality. More research is needed to establish an evidence-based treatment algorithm for patients with this challenging pain problem. In line with the WHO recommendation, greater emphasis should be placed on a biopsychosocial approach. The ultimate goal should be the development of a generic treatment algorithm outlining an approach to ACNES applicable to all professionals involved.

Three Subtypes of Cutaneous Nerve Entrapment Syndrome: A Narrative Review.

Anterior, lateral, and posterior cutaneous nerve entrapment syndromes have been proposed as etiologies of trunk pain. However, while these syndromes are analogous, comprehensive reports contrasting the three subtypes are lacking. We therefore reviewed the literature on anterior, lateral, and posterior cutaneous nerve entrapment syndrome. We searched the PubMed and Cochrane Library databases twice for relevant articles published between March and September 2022. In addition to 16 letters, technical reports, and review articles, a further 62, 6, and 3 articles concerning anterior, lateral, and posterior cutaneous nerve entrapment syndromes, respectively, were included. These syndromes are usually diagnosed based solely on unique history and examination findings; however, the diagnostic process may be prolonged, and multiple re-evaluations are required. The most common first-line treatment is trigger point injection; however, the management of refractory cases remains unclear. Awareness of this disease should be expanded to medical departments other than general medicine.

Pulsed radiofrequency or surgery for anterior cutaneous nerve entrapment syndrome: Long-term results of a randomized controlled trial.

Patients with anterior cutaneous nerve entrapment syndrome (ACNES) often require a step-up treatment strategy including abdominal wall injections, pulsed radiofrequency (PRF) or a neurectomy. Long-term success rates of PRF and surgery are largely unknown. The aim of the current study was to report on the long-term efficacy of PRF and neurectomy in ACNES patients who earlier participated in the randomized controlled PULSE trial. Patients who completed the PULSE trial were contacted about pain status and additional treatments in the following years. Treatment success was based on numerical rating scale (NRS) following IMMPACT recommendations and Patient Global Impression of Change (PGIC) scores. A total of 44 of the original 60 patients were eligible for analysis (73.3%). Median follow-up was 71.5 months. One patient (4.3%) was still free of pain after a single PRF session, and five additional patients (21.7%) were free of pain by repetitive PRF treatments. By contrast, 13 patients (61.9%) in the neurectomy group were still free of pain without additional treatments. All pain recurrences and therefore primary re-interventions occurred in the first 2 years after the initial treatment. Approximately one in five ACNES patients undergoing PRF treatment reports long-term success obviating the need of surgical intervention. Surgery for ACNES is long-term effective in approximately two of three operated patients. Recurrent ACNES beyond 2 years after either intervention is rare.

A Prospective Study on the Diagnoses for Abdominal Pain After Bariatric Surgery: The OPERATE Study

PurposeLong-term follow-up after bariatric surgery (BS) reveals high numbers of patients with abdominal pain that often remains unexplained. The aim of this prospective study was to give an overview of diagnoses for abdominal pain, percentage of unexplained complaints, number and yield of follow-up visits, and time to establish a diagnosis.Materials and MethodsPatients who visited the Spaarne Gasthuis Hospital, The Netherlands, between December 2020 and December 2021 for abdominal pain after BS, were eligible and followed throughout the entire episode of abdominal pain. Distinction was made between presumed and definitive diagnoses.ResultsThe study comprised 441 patients with abdominal pain; 401 (90.9%) females, 380 (87.7%) had Roux-en-Y gastric bypass, mean (SD) % total weight loss was 31.4 (10.5), and median (IQR) time after BS was 37.0 (11.0–66.0) months. Most patients had 1–5 follow-up visits. Readmissions and reoperations were present in 212 (48.1%) and 164 (37.2%) patients. At the end of the episode, 88 (20.0%) patients had a presumed diagnosis, 183 (41.5%) a definitive diagnosis, and 170 (38.5%) unexplained complaints. Most common definitive diagnoses were cholelithiasis, ulcers, internal herniations, and presumed diagnoses irritable bowel syndrome (IBS), anterior cutaneous nerve entrapment syndrome, and constipation. Median (IQR) time to presumed diagnoses, definitive diagnoses, or unexplained complaints was 16.0 (3.8–44.5), 2.0 (0.0–31.5), and 13.5 (1.0–53.8) days (p < 0.001). Patients with IBS more often had unexplained complaints (OR 95%CI: 4.457 [1.455–13.654], p = 0.009). At the end, 71 patients (16.1%) still experienced abdominal pain.ConclusionOver a third of abdominal complaints after BS remains unexplained. Most common diagnoses were cholelithiasis, ulcers, and internal herniations.Graphical

The burden of abdominal pain after bariatric surgery in terms of diagnostic testing: the OPERATE study

BackgroundAbdominal pain after bariatric surgery (BS) is frequently observed. Despite numerous diagnostic tests, the cause of abdominal pain is not always found. ObjectivesTo quantify type and number of diagnostic tests performed in patients with abdominal pain after BS and evaluate the burden and their yield in the diagnostic process. SettingA bariatric center in the Netherlands. MethodsIn this prospective study, we included patients who presented with abdominal pain after BS between December 1, 2020, and December 1, 2021. All diagnostic tests and reoperations performed during one episode of abdominal pain were scored using a standardized protocol. ResultsA total of 441 patients were included; 401 (90.9%) were female, median time after BS was 37.0 months (IQR, 11.0–66.0) and mean percentage total weight loss was 31.41 (SD, 10.53). In total, 715 diagnostic tests were performed, of which 355 were abdominal CT scans, 155 were ultrasounds, and 106 were gastroscopies. These tests yielded a possible explanation for the pain in 40.2% of CT scans, 45.3% of ultrasounds, and 34.7% of gastroscopies. The diagnoses of internal herniation, ileus, and nephrolithiasis generally required only 1 diagnostic test, whereas patients with anterior cutaneous nerve entrapment syndrome, irritable bowel syndrome, and constipation required several tests before diagnosis. Even after several negative tests, a diagnosis was still found in the subsequent test: 86.7% of patients with 5 or more tests had a definitive diagnoses. Reoperations were performed in 37.2% of patients. ConclusionThe diagnostic burden in patients with abdominal pain following BS is high. The most frequently performed diagnostic test is an abdominal CT scan, yielding the highest number of diagnoses in these patients.

Visceral symptoms in patients with anterior cutaneous nerve entrapment syndrome (ACNES): expression of viscerosomatic reflexes?

PurposeAnterior cutaneous nerve entrapment (ACNES) is characterized by neuropathic pain in a predictable, circumscript abdominal area. The diagnostic delay is long, with half of ACNES-affected individuals reporting nausea, bloating, or loss of appetite mimicking visceral disease. The aim of this study was to describe these phenomena and to determine whether treatment could successfully reverse the visceral symptoms.MethodsThis prospective observational study was conducted between July 2017 and December 2020 at SolviMáx, Center of Excellence for Chronic Abdominal Wall and Groin Pain, Máxima Medical Center, Eindhoven. Adult patients who fulfilled published criteria for ACNES and reported at least one visceral symptom at intake were eligible for the study. A self-developed Visceral Complaints ACNES Score (VICAS) questionnaire that scores several visceral symptoms (minimum 1 point, maximum 9 points) was completed before and after therapy. The success of treatment was defined as at least 50% reduction in pain.ResultsData from 100 selected patients (86 females) aged 39 ± 5 years were available for analysis. Frequently reported symptoms were abdominal bloating (78%), nausea (66%) and altered defecation (50%). Successful treatment significantly reduced the number of visceral symptoms, with a VICAS before of 3 (range 1–8) and after of 1 (range 0–6) (p < 0.001). A low baseline VICAS was associated with successful treatment outcome (OR 0.738, 95% CI 0.546–0.999).ConclusionPatients with ACNES may report a variety of visceral symptoms. Successful treatment substantially reduces these visceral symptoms in selected patients.

Percutaneously Inserted Continuous Peripheral Nerve Block Catheter as a Novel Minimal Invasive Treatment of Abdominal Cutaneous Nerve Entrapment Syndrome (ACNES): A Pilot Study to Assess Efficacy of This Novel Treatment

Percutaneously Inserted Continuous Peripheral Nerve Block Catheter as a Novel Minimal Invasive Treatment of Abdominal Cutaneous Nerve Entrapment Syndrome (ACNES): A Pilot Study to Assess Efficacy of This Novel Treatment

A Case of Chronic Postoperative Abdominal Wall Pain Successfully Treated with the Fascial Distortion Model

Abstract We describe the case of a 55-year-old female with nine months of chronic postoperative abdominal wall pain likely representing anterior cutaneous nerve entrapment syndrome (ACNES), who experienced marked symptomatic improvement with the use of the fascial distortion model (FDM) in the emergency department (ED). This is the first case report in the literature on the successful application of the FDM for abdominal wall pain, and there is still little FDM literature in the emergency medicine (EM) setting.

ХИРУРГИЧЕСКОЕ ЛЕЧЕНИЕ ПАЦИЕНТА С СИНДРОМОМ СДАВЛЕНИЯ ПЕРЕДНЕГО КОЖНОГО НЕРВА БРЮШНОЙ СТЕНКИ

The purpose of the presented observation is the possibility of performing single-step surgical treatment for anterior cutaneous nerve entrapment syndrome. Scientific validity of the research is in modern surgery technique with precision tissue preparation. As a result, a positive outcome of the pathology.

Anterior cutaneous nerve entrapment syndrome in children.

I frequently see adolescents with recurrent abdominal pain in my family medicine clinic. While the diagnosis frequently is a benign condition such as constipation, I recently heard that after 2 years of recurrent pain, an adolescent was diagnosed with anterior cutaneous nerve entrapment syndrome (ACNES). How is this condition diagnosed? What is the recommended treatment? Anterior cutaneous nerve entrapment syndrome, first described almost 100 years ago, is caused by entrapment of the anterior branch of the abdominal cutaneous nerve as it pierces the anterior rectus abdominis muscle fascia. The limited awareness of the condition in North America results in misdiagnosis and delayed diagnosis. Carnett sign-in which pain worsens when using a "hook-shaped" finger to palpate a purposefully tense abdominal wall-helps to confirm if pain originates from the abdominal viscera or from the abdominal wall. Acetaminophen and nonsteroidal anti-inflammatory drugs were not found to be effective, but ultrasound-guided local anesthetic injections seem to be an effective and safe treatment for ACNES, resulting in relief of pain in most adolescents. For those with ACNES and ongoing pain, surgical cutaneous neurectomy by a pediatric surgeon should be considered.

Treatment of anterior cutaneous nerve entrapment syndrome using an ultrasound-guided transverse abdominis plane block

Introduction: Anterior cutaneous nerve entrapment syndrome (ACNES) is increasingly being considered to be a common cause of abdominal pain. Unfortunately, ACNES is a condition that is frequently overlooked and misdiagnosed resulting in chronic abdominal wall pain, unnecessary investigations, procedures, and repeat admissions. Patients diagnosed with ACNES present with well-localized abdominal pain, a positive Carnett’s sign, somatosensory disturbance of the surrounding skin and symptomatic relief secondary to a trigger point injection. Current treatment strategies include modification of physical activity, simple analgesia, trigger point injections, chemical neurolysis, pulsed radiofrequency, and anterior neurectomy. Despite the plethora of treatment modalities, it is evident that a majority of patients will only experience temporary pain relief. Case Series: We describe two cases in which ultrasound-guided transverse abdominal plane blocks have successfully provided long-term symptomatic relief in patients diagnosed with ACNES. The first being a 45-year-old female and the second is a 52-year-old male who both presented with ACNES which were successfully treated with an ultrasound-guided transverse abdominal plane (TAP) block with 20 mL of 0.25% Marcaine and 4 mg of Dexamethasone. Conclusion: We provide evidence supporting the use of an ultrasound-guided TAP block for long-term symptomatic relief in patients with ACNES. However, further research is required to assess its efficacy.