Characteristics of 1116 Consecutive Patients Diagnosed With Anterior Cutaneous Nerve Entrapment Syndrome (ACNES)

Spectrum of abdominal anterior cutaneous nerve entrapment syndrome (ACNES) with successful management: a case report

Abdominal pain is a common symptom with a spectrum of causes. Anterior cutaneous nerve entrapment syndrome (ACNES) is a commonly overlooked and underdiagnosed cause for anterior abdominal pain. Among the patients of chronic abdominal wall pain, the incidence of ACNES is 10-30% and the most common cause is nerve entrapment at the lateral border of the rectus muscle. We describe two cases covering varied location of entrapment, one at the medial border of rectus and another at lateral border explaining the need of ultrasound for successful management of both. This case report illustrates the difficulty of making this diagnosis, utility of ultrasound and a brief review of literature.

Anterior Cutaneous Nerve Entrapment Syndrome Caused by a Fixation Device: A Case Report

Anterior cutaneous nerve entrapment syndrome (ACNES) is characterized by abdominal wall neuralgia. We report an 85-year-old woman with ACNES caused by a fixation device during the bipolar hip arthroplasty. To prevent ACNES as a perioperative peripheral nerve injury, it is important to maintain patients in the appropriate position during the operation. A positive Carnett's sign means the abdominal pain originates from the abdominal wall and is useful in diagnosing ACNES. Thus, physicians should examine Carnett's sign to differentiate ACNES in patients with abdominal pain developing after an operation.

Parietal abdominal pain with lower leg discrepancy: a case report

BACKGROUND

This report involves the first publication describing a case of parietal abdominal pain due to lower limb length discrepancy.

CASE PRESENTATION

A Caucasian male patient in his 50s was referred to our rehabilitation department with chronic abdominal pain that began in childhood. This chronic pain was associated with episodes of acute pain that were partially relieved by grade 3 analgesics. The patient was unable to sit for long periods, had recently lost his job, and was unable to participate in recreational activities with his children. Investigations revealed contracture and hypertrophy of the external oblique muscle and an limb length discrepancy of 3.8 cm (1.5 inches) in the left lower limb. The patient was effectively treated with a heel raise, physiotherapy, intramuscular injection of botulinum toxin, and lidocaine. The patient achieved the therapeutic goals of returning to work, and reducing analgesic use.

CONCLUSIONS

Structural misbalances, as may be caused by lower leg discrepancy, may trigger muscular compensations and pain. Complete anamnesis and clinical examination must not be trivialized and may reveal previously ignored information leading to a proper diagnosis.

Groin Pain Syndrome Italian Consensus Conference update 2023

Groin pain syndrome (GPS) is a controversial topic in Sports Medicine. The GPS Italian Consensus Conference on terminology, clinical evaluation and imaging assessment of groin pain in athletes was organized by the Italian Society of Arthroscopy in Milan, on 5 February 2016. In this Consensus Conference (CC) GPS etiology was divided into 11 different categories for a total of 63 pathologies. The GPS Italian Consensus Conference update 2023 is an update of the 2016 CC. The CC was based on a sequential, two-round online Delphi survey, followed by a final CC in the presence of all panelists. The panel was composed of 55 experts from different scientific and clinical backgrounds. Each expert discussed 6 different documents, one of which regarded the clinical and imaging definition of sports hernias, and the other 5 dealt with 5 new clinical situations thought to result in GPS. The panelists came to an agreement on the definition of a sports hernia. Furthermore, an agreement was reached, recognizing 4 of the 5 possible proposed pathologies as causes to GPS. On the contrary, the sixth pathology discussed did not find consensus given the insufficient evidence in the available scientific literature. The final document includes a new clinical and imaging definition of sports hernia. Furthermore, the etiology of GPS was updated compared to the previous CC of 2016. The new taxonomic classification includes 12 categories (versus 11 in the previous CC) and 67 pathologies (versus 63 in the previous CC).

The Diagnostic Value of Carnett's Test with Chronic Abdominal Pain: A Narrative Review

PURPOSE OF REVIEW

Chronic abdominal wall pain is a poorly recognized cause of chronic abdominal pain, and patients frequently go misdiagnosed despite a battery of medical tests. The Carnett's test is a diagnostic tool used to distinguish between abdominal wall pain and visceral pain. This review synthesizes the current literature on the Carnett's test, merges the viewpoints of diverse writers, and evaluates and reports on the Carnett's test's applicability.

RECENT FINDINGS

Several clinical investigations have established the usefulness of the Carnett's test in the diagnosis of chronic abdominal wall pain. Furthermore, the Carnett's test is quite useful in determining the depth of the mass and detecting psychogenic abdominal pain. However, its diagnostic use for acute abdominal pain is limited. The Carnett's test is a simple and safe point-of-care diagnostic technique, with several studies supporting its usefulness. Early detection of abdominal wall pain is critical for chronic abdominal wall pain therapy. Carnett's test is very useful in patients with chronic, unexplained local abdominal discomfort who are compliant and do not have a clear rationale for surgery.

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

PURPOSE

Anterior 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.

METHODS

This 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.

RESULTS

Data 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).

CONCLUSION

Patients with ACNES may report a variety of visceral symptoms. Successful treatment substantially reduces these visceral symptoms in selected patients.

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

PURPOSE

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

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.

Interventional pathway in the management of refractory post cholecystectomy pain (PCP) syndrome: a 6-year prospective audit in 60 patients

OBJECTIVES

Post cholecystectomy pain syndrome can affect over a third of patients undergoing laparoscopic cholecystectomy. Acute exacerbations can result in recurrent emergency admission with excessive healthcare utilization. Standard surgical management appears to focus on visceral aetiology. Abdominal myofascial pain syndrome is a poorly recognised somatic pathology that can cause refractory pain in this cohort. It develops as a result of trigger points in the abdominal musculature. The report describes the pathophysiology and a novel interventional pathway in the management of post cholecystectomy pain secondary to abdominal myofascial pain syndrome.

METHODS

The prospective longitudinal audit was performed at a tertiary pain medicine clinic in a university teaching hospital. Over a six-year period, adult patients with refractory abdominal pain following laparoscopic cholecystectomy were included in a structured interventional management pathway. The pathway included two interventions. Intervention I was a combination of abdominal plane blocks and epigastric port site trigger injection with steroids. Patients who failed to report durable relief (>50% pain relief at 12 weeks) were offered pulsed radiofrequency treatment to the abdominal planes (Intervention II). Outcomes included patient satisfaction, change in opioid consumption and impact on emergency visits.

RESULTS

Sixty patients who failed to respond to standard management were offered the pathway. Four patients refused due to needle phobia. Fifty-six patients received Intervention I. Failure rate was 14% (8/56). Forty-eight patients (48/56, 86%) reported significant benefit at 12 weeks while 38 patients reported durable relief at 24 weeks (38/56, 68%). Nine patients received Intervention II and all (100%) reported durable relief. Emergency admissions and opioid consumption were reduced.

CONCLUSIONS

Abdominal myofascial pain syndrome is a poorly recognised cause of post cholecystectomy pain. The novel interventional management pathway could be an effective solution in patients who fail to benefit from standard management.

A Novel Approach to Assessing and Conservatively Treating Anterior Cutaneous Nerve Entrapment Syndrome: A Case Study

Anterior cutaneous nerve entrapment syndrome (ACNES) is a common source of chronic abdominal pain and is often underdiagnosed despite numerous and potentially invasive diagnostic evaluations and tests. We present a case report describing a novel, conservative, and non-invasive approach to diagnose and treat recurrent ACNES in a young and active patient. We describe a treatment-based diagnostic approach to confirm potential ACNES pain generators while recording pre- and post-treatment pain scores. After each maneuver, the patient was reassessed which allowed the working diagnosis to clinically evolve demonstrating the pathologic interrelationship between different skeletal structures and myofascial tissues contributing to irritation of the anterior cutaneous nerve. This treatment-based technique also made it possible to identify referred pain from a condition with overlapping symptoms originating from a different anatomic site. Treatment consisted of sequenced osteopathic manipulation techniques, active release techniques, instrument-assisted soft tissue mobilization, directional cupping, stretching, and strengthening exercises. The combination of sequenced treatments over the course of six physical therapy visits spanning 10 weeks resulted in 100% pain reduction and complete resolution of functional limitations. The patient was able to complete all work requirements and physical activity without pain. A sequenced treatment-based diagnostic approach to this case allowed us to more accurately identify all involved anatomic regions of pain and anatomic segments of pathology that were contributing to the abdominal pain or referring pain. No diagnostic imaging, invasive test, or injection was needed to properly diagnose and treat this case of ACNES. A proper understanding and application of osteopathic manipulation, active release techniques, instrument-assisted soft tissue mobilization, cupping, and exercises successfully resolved the contributing pain conditions and provided the patient important and useful tools and strategies to prevent recurrence.

The Scratch Collapse Test in patients diagnosed with Anterior Cutaneous Nerve Entrapment Syndrome (ACNES): A report of three cases

INTRODUCTION AND IMPORTANCE

The Scratch Collapse Test (SCT) is currently used as a supportive tool diagnosing peripheral nerve neuropathies including carpal tunnel syndrome or peroneal nerve entrapment. Some patients with chronic abdominal pain suffer from entrapment of terminal branches of intercostal nerves (anterior cutaneous nerve entrapment syndrome, ACNES). ACNES is characterized by a severe disabling pain at a predictable area of the anterior abdomen. Clinical examination shows altered skin sensation and painful pinching at the area of pain. However, these findings may be subjective.

CASE PRESENTATION

In three female patients aged 71, 33, and 43 years with suspected ACNES, the SCT was positive when scratching over the skin of the affected nerve-ending at the abdominal wall. The diagnosis ACNES was confirmed with a local abdominal wall infiltration at the tenderpoint in all three patients. In case three, the SCT turned negative after lidocaine infiltration.

CLINICAL DISCUSSION

ACNES was hitherto a clinical diagnosis just based on clues in medical history and physical examination. Performing a SCT in patients possibly having ACNES may additionally contribute to the diagnosis.

CONCLUSION

The SCT may serve as an additional tool for diagnosing patients with possible ACNES. A positive SCT in patients with ACNES supports the hypothesis that ACNES is indeed a peripheral neuropathy of terminal branches of the lower thoracic intercostal nerves. Controlled research is necessary to confirm the role of a SCT in ACNES.

Abdominal Pain in a 15-Year-Old Adolescent Girl

A 15-year-old adolescent girl taking an oral contraceptive had 3 days of pain in a 1-cm area of the lower left abdominal quadrant. She had no nausea/vomiting, diarrhea, hematochezia, bloating, or anorexia; no precipitating factors for the pain; and no history of pregnancy, abdominal surgery, or abdominal trauma. Results from laboratory tests, endoscopy, and abdominal computed tomography were normal. What is the diagnosis and what would you do next?

Abdominal cutaneous nerve entrapment syndrome: A cross sectional survey of treatment outcomes

Objective

Abdominal Cutaneous Nerve Entrapment Syndrome (ACNES) is a common but under recognised cause of chronic abdominal wall Pain. This survey was carried out to understand the clinical course of the condition following interventions such as nerve blocks and surgical release of entrapped nerve.

Design

Retrospective, Cross-sectional survey.

Setting

Pain Management clinic at University teaching hospital.

Subjects

Adult patients who had interventions either nerve block or surgical release over a 6 year period.

Methods

After written informed consent, participants completed a questionnaire including Brief Pain Inventory (BPI), quality of health measure (EQ-5D-5L), and global impression of change scale as well as open-ended question about the outcomes. Baseline demographics, details of pain condition, interventions received were collected from the health records.

Results

The diagnosis of ACNES was established in 85.2% by ultrasound guided injections. The injection therapy with local anaesthetic and steroid was successful to 75.8% while the surgical release was successful in 90%. The cumulative duration of pain relief varied from 3 weeks to 5 years. A significant difference was noted in BPI (p = 0.001), EQ-5D-5L (p = 0.002) and health thermometer (p = 0.009) post interventions.

Conclusions

Ultrasound guided injections aid the accurate diagnosis of ACNES. Appropriate treatment of ACNES improves both pain control and quality of life.

A Rare Presentation of a Compression Fracture or a Typical Presentation of Lateral Cutaneous Nerve Entrapment Syndrome: A Diagnostic Error?

A 78-year-old woman complained of severe pain in the left costal region. Her body mass index was 23.1 kg/m2. Lateral cutaneous nerve entrapment syndrome (LACNES) was the suspected diagnosis because the affected area was 2×2 cm and positive for pinch sign. Seventeen days later, the patient again presented with complaints of lower back pain accompanied by back pain upon extending the spine. Magnetic resonance imaging of the spine showed a fracture of the vertebral body of T11. We herein discuss our errors in the diagnostic process and critical tactics for avoiding such errors in the future.

Ultrasound-guided abdominal wall infiltration versus freehand technique in anterior cutaneous nerve entrapment syndrome (ACNES): randomized clinical trial

Background

The optimal technique of abdominal wall infiltration for chronic abdominal wall pain due to anterior cutaneous nerve entrapment syndrome (ACNES) is unknown. The aim of this study was to compare pain reduction after an abdominal wall anaesthetic injection by use of an ultrasound-guided technique (US) or given freehand (FH).

Methods

In this multicentre non-blinded randomized trial, adult patients with ACNES were randomized (1:1) to an US or a FH injection technique. Primary outcome was the proportion of injections achieving a minimum of 50 per cent pain reduction on the Numeric Rating Scale (range 0–10) 15–20 min after abdominal wall infiltration (‘successful response’). Secondary outcomes were treatment efficacy after 6 weeks and 3 months, and the influence of the subcutaneous tissue thickness on treatment outcome.

Results

Between January 2018 and April 2020, 391 injections (US = 192, FH = 199) were administered in 117 randomized patients (US = 55, FH = 62; 76.0 per cent female, mean age 45 years). The proportion of successful responses did not significantly differ immediately after the injection regimen (US 27.1 per cent versus FH 33.2 per cent; P = 0.19) or after 3 months (US 29.4 per cent versus FH 30.5 per cent; P = 0.90). Success was not determined by subcutaneous tissue thickness.

Conclusion

Pain relief following abdominal wall infiltration by a US or FH technique in ACNES is similar and not influenced by subcutaneous tissue thickness.

Registration number

Dutch Clinical Trial Register NL8465.

Diagnostic Effect of Consultation Referral from Gastroenterologists to Generalists in Patients with Undiagnosed Chronic Abdominal Pain: A Retrospective Study

This study aimed to investigate consultation outcomes from gastroenterologists to generalist physicians for the diagnostic workup of undiagnosed chronic abdominal pain. This was a single-center, retrospective, descriptive study. Patients were included who were ≥15 years old and consulted from the Department of Gastroenterology to the Department of Diagnostic Medicine, to establish a diagnosis for chronic abdominal pain, at the Dokkyo University Hospital from 1 April 2016 to 31 August 2020. We retrospectively reviewed the patients' medical charts and extracted data. A total of 12 cases were included. Eight patients (66.7%) were diagnosed with and treated for functional gastrointestinal disorders (FGID) at the Department of Gastroenterology; their lack of improvement under treatment for FGID was the reason for their referral to the Department of Diagnostic Medicine for further examination. After this consultation, new possible diagnoses were generated for eight patients (66.7%). Six of the eight patients (75.0%) were diagnosed with abdominal wall pain (anterior cutaneous nerve entrapment syndrome, n = 3; myofascial pain, n = 1; falciform pain, n = 1; and herpes zoster non-herpeticus; n = 1). Consultation referral from gastroenterologists to generalists could generate new possible diagnoses in approximately 70% of patients with undiagnosed chronic abdominal pain.

Chronic Abdominal Pain After Previous Bariatric Surgery: Consider the Abdominal Wall

BACKGROUND

Up to 30% of patients who undergo bariatric surgery experience recurrent abdominal pain within 3 years after the operation. Although some causes for persisting discomfort are well known, a small portion of patients may suffer from an abdominal wall pain associated with Anterior Cutaneous Nerve Entrapment Syndrome (ACNES). Aim of the present study is to discuss incidence, clinical presentation, and treatment outcome in patients with ACNES after bariatric surgery.

METHODS

This retrospective observational cohort study analyzed electronically stored data of patients with ACNES having a history of bariatric surgery. All were treated for ACNES between 2011 and 2017 in a Dutch center of excellence for abdominal wall and groin pain. Success after treatment was defined as a minimal 50% drop in pain level using a Numeric Rating Scale.

RESULTS

A total of 49 patients (female n = 44, median age 45 (25-63) years) were identified. Four (8%) experienced long-term pain relief after just one abdominal wall infiltration with lidocaine. Ten additional patients reported success after 2-5 injections. A total of 35 unresponsive patients chose to undergo a neurectomy that was successful in 27. Therefore, this step-up approach conferred an 84% success rate. Occurrence of ACNES after bariatric surgery was estimated at 1 in 100 patients.

CONCLUSION

ACNES should be considered in the differential diagnosis of ongoing pain following previous bariatric surgery. A treatment regimen including abdominal wall infiltrations using an anesthetic agent or a neurectomy is successful in a vast majority of these patients.

Recurrent anterior cutaneous nerve entrapment syndrome (ACNES) in three consecutive pregnancies

A 31-year-old G2P1001 woman at a 30-week gestation presented with a recurrence of pinpoint right upper abdominal wall pain. She had been diagnosed with an anterior cutaneous nerve entrapment syndrome (ACNES) during her first pregnancy at a similar gestational age, a well-described but frequently under-recognised entity. The pain during that pregnancy resolved immediately and completely following normal spontaneous vaginal delivery, however,the pain was worse with this presenting pregnancy. She underwent an ultrasound-guided rectus sheath nerve block at 30 weeks with complete and immediate relief for the remainder of the pregnancy. During a third pregnancy, she suffered another recurrence; however, it was less severe than in the prior pregnancies and was managed conservatively. It again resolved completely and immediately with normal spontaneous vaginal delivery. The pattern of ACNES recurrence during the same gestational age in all three pregnancies with total relief following deliveries demonstrates a clear primary mechanical aetiology.

Anterior Cutaneous Nerve Entrapment Syndrome Occurring after Endoscopy

A 45-year-old lady presented for a follow-up endoscopy examination for mild abdominal pain due to gastric ulcers. She experienced a severe, markedly different type of pain with labor-like contractions 3 days later. Physical examination revealed tenderness confined to a 1 × 1-cm area and positive Carnett's sign. The pain completely resolved 10 min after a subcutaneous lidocaine injection. The patient was diagnosed with anterior cutaneous nerve entrapment syndrome. The pain returned within several hours and anterior neurectomy was performed several days later. The pain subsided immediately and no recurrence was seen during 3 years of follow-up.