Chronic abdominal wall pain--a diagnostic challenge for the surgeon

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.

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).

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.

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 case for ultrasound-guided peripheral nerve stimulation in intractable anterior cutaneous nerve entrapment syndrome

Aim: This case report documents the use of peripheral nerve stimulation in the setting of entrapment of the anterior cutaneous branches of the intercostal nerves, with pain rated by the patient as severe during exacerbation episodes. Materials & methods: Under ultrasound guidance, two permanent leads were implanted caudad to cephalad, along and superficial to the lateral aspect of the rectus abdominis, distal to the umbilicus (1 lead per side). Results: At the 6 month follow-up, the patient reported near complete resolution of baseline pain, as well as fewer, sporadic pain exacerbation episodes, rated as mild-to-moderate. Conclusion: This case report suggests that peripheral nerve stimulation might be a valuable treatment option for previously intractable abdominal pain due to entrapment of the anterior cutaneous branches.

Review article: diagnostic and therapeutic approach to persistent abdominal pain beyond irritable bowel syndrome

BACKGROUND

Persistent abdominal pain (PAP) poses substantial challenges to patients, physicians and healthcare systems. The possible aetiologies of PAP vary widely across organ systems, which leads to extensive and repetitive diagnostic testing that often fails to provide satisfactory answers. As a result, widely recognised functional disorders of the gut-brain interaction, such as irritable bowel syndrome and functional dyspepsia, are often diagnosed in patients with PAP. However, there are a number of less well-known differential diagnoses that deserve consideration.

AIM

To provide a comprehensive update on causes of PAP that are relatively rare in occurrence.

METHODS

A literature review on the diagnosis and management of some less well-known causes of PAP.

RESULTS

Specific algorithms for the diagnostic work-up of PAP do not exist. Instead, appropriate investigations tailored to patient medical history and physical examination findings should be made on a case-by-case basis. After a definitive diagnosis has been reached, some causes of PAP can be effectively treated using established approaches. Other causes are more complex and may benefit from a multidisciplinary approach involving gastroenterologists, pain specialists, psychologists and physiotherapists. This list is inclusive but not exhaustive of all the rare or less well-known diseases potentially associated with PAP.

CONCLUSIONS

Persistent abdominal pain (PAP) is a challenging condition to diagnose and treat. Many patients undergo repeated diagnostic testing and treatment, including surgery, without achieving symptom relief. Increasing physician awareness of the various causes of PAP, especially of rare diseases that are less well known, may improve patient outcomes.

Nerve Identification Procedures Are Necessary for Complete Recovery From Recurrent Cases of Anterior Cutaneous Nerve Entrapment Syndrome: A Case Report

Anterior cutaneous nerve entrapment syndrome (ACNES) involves pain in the abdominal wall due to nerve compression or ischemia. The diagnosis of ACNES is challenging with the pain often inclined to be diagnosed as psychological in origin. A 20-year-old woman presenting with abdominal pain was initially diagnosed with mesenteric lymphadenitis and prescribed pain relievers. However, following worsened pain, she was hospitalized. Blood examinations, abdominal and gynecological ultrasonography, and gastrocolonoscopy yielded no abnormal findings, leading to suspicions of psychological factors. As the patient experienced sharp abdominal pain on movement, but not at rest, which was temporarily relieved by lidocaine injections, she was diagnosed with ACNES. Rectus abdominal resection was performed but the pain relapsed. Laparoscopic surgery was performed to cut the nerve that caused the pain. After three surgeries, the patient was completely symptom-free. ACNES should be considered as a differential diagnosis for intractable abdominal pain. For recurrent relapses, the triggering nerves must be carefully identified for the successful treatment of ACNES.

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.

Thoracic disk herniation diagnosed with an upper body traction procedure in the sitting position

A 51-year-old man experienced sudden abdominal pain from the umbilicus to the right flank 5 days before his hospital visit. His abdominal pain disappeared when the examiner lifted his upper body in the sitting position. MRI revealed posterior intervertebral disc protrusion in the right paramedian region at the 9th/10th thoracic vertebrae. With the treatment, it is reported that traction is the appropriate initial approach for spine radiculopathy. Improvement with upper body traction performed in this case, which is a previously unreported maneuver, appears to be useful for diagnosis because it eliminates the influence of gravity and reduces intradiscal pressure.

Surgical Management of Abdominal Anterior Cutaneous Nerve Entrapment Syndrome: Case Report, Surgical Technique, and Literature Review

Background:

Abdominal anterior cutaneous nerve entrapment syndrome (ACNES) is an emerging diagnosis, with estimated incidence of 13%–30% of the adult population. It is a syndrome characterized by chronic abdominal pain caused by entrapment of cutaneous branches of thoracoabdominal nerves at the lateral border of the rectus abdominis muscle. If conservative treatment with pain medication, botulinum toxin, or lidocaine injections is inadequate, surgical management is indicated.

Methods:

We present a case of a 40-year-old woman presenting with a 1-year history of daily right anterior abdominal wall pain, consistent with a diagnosis of ACNES. We describe our approach for an anterior neurectomy of the intercostal nerve with closure of its fascial foramen.

Results:

Three months after surgery, she remained pain free and was back to work full time. At a 13-month follow-up, the patient reported that her pain had resolved completely following surgery.

Conclusions:

Results are encouraging following anterior neurectomy for ACNES. Surgical descriptions in the literature are brief, with limited pictorial account. Our detailed surgical approach is provided along with a review of the existing literature on the management of ACNES.

Chronic Abdominal Pain in General Practice

Background and Summary: Chronic abdominal pain is a challenging complaint for both primary care providers and gastroenterologists alike, due to a broad differential diagnosis and sometimes extensive and negative workup. In the absence of red flag features that herald more acute conditions, the majority of patients with chronic abdominal pain have a benign cause or a functional disorder (e.g., irritable bowel syndrome). The costs associated with a diagnostic workup are an expensive burden to health care. A systematic approach for evaluating patients and initiating a management plan are recommended in the primary care setting. Undiagnosed abdominal pain should be investigated starting with a detailed history and physical examination. Diagnostic investigations should be limited and adapted according to the clinical features, the alarm symptoms, and the symptom severity. This review will focus on the diagnostic tools which general practitioners utilize in the evaluation of chronic abdominal pain. Key Messages: The primary role of the general practitioner is to differentiate an organic disease from a functional one, to refer to a specialist, or to provide treatment for the underlying cause of pain. The functional disorders should be considered after the organic pathology has been confidently excluded. Once a diagnosis of functional pain is established, repetitive testing is not recommended and the patient should be referred to receive psychological support (e.g., cognitive therapy) associated with available pharmacological therapeutic options.

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

OBJECTIVE

The aim of this study was to discuss patient history and subjective findings at physical examination in a large case series to validate a proposed comprehensive set of major and minor diagnostic criteria.

SUMMARY BACKGROUND DATA

Chronic abdominal pain in some patients is caused by the anterior cutaneous nerve entrapment syndrome (ACNES). ACNES is a clinical diagnosis as no functional testing or imaging modalities are available up to date.

METHODS

This study retrospectively analyzed prospectively obtained data from consecutive patients who received the diagnosis ACNES during evaluation at the SolviMáx Center of Excellence for Abdominal Wall and Groin Pain, Eindhoven, The Netherlands, between June 1, 2011 and September 1, 2016. Questionnaires, standard case forms, and digital case files containing characteristics of individuals were used for analysis.

RESULTS

Data of 1116 patients suspected and treated for ACNES consistently showed the presence of the following 4 characteristics: sensory disturbances at the painful abdominal area (78%), a positive pinch sign (78%), a positive Carnett's sign (87%), and a positive response to a modified rectus sheath block (>50% pain reduction, 81%). The majority of patients are female of young or middle age with a normal BMI reporting complaints that occurred spontaneously in either a sudden or gradual timeframe, developing a severe (NRS 6-8) chronic abdominal pain that was only diagnosed after a substantial doctor's delay.

CONCLUSION

A combination of typical findings in history and physical examination, combined with a positive modified rectus sheath block, may allow for diagnosing ACNES in patients with chronic abdominal pain.

A Novel Approach to Assessing and Treating Musculoskeletal-Mediated Atypical Abdominal Pain: A Case Study

Abdominal pain is a common and functionally limiting complaint within the healthcare system linked to impaired quality of life and increased health care utilization. This chief complaint is associated with an extensive differential diagnosis leading to high utilization of diagnostic testing, increased healthcare cost, and delayed access to care. In patients presenting with acute or chronic abdominal pain, musculoskeletal pain often requires expensive testing, thereby delaying definitive care. An improved triage process is warranted. Performing a musculoskeletal examination to determine if pain patterns can be mechanically reproduced at the site of origin, or remote to the site of pain, warrants referral to a musculoskeletal specialist. In our young and healthy population, once the musculoskeletal mediated abdominal pain origin is determined, we see significant success in the application of a treatment approach consisting of manipulative therapy, exercise, and instrument-assisted soft tissue mobilization. A multimodal treatment approach for musculoskeletal-mediated abdominal pain has not been previously described. This case study outlines a novel management approach for musculoskeletal-mediated abdominal pain and provides an alternative diagnostic technique, when implemented early in the evaluation and management process of atypical abdominal pain, that improves the quality of life.

Sonography-guided trigger point injections in abdominal myofascial pain syndrome

Even though chronic abdominal pain is 1 of the most common reasons for hospital visits, diagnostic testing is often time-consuming and treatment is inadequate. Abdominal myofascial pain syndrome (AMPS) is usually not included as a differential diagnosis, but it should be considered in cases of chronic abdominal pain. The purpose of this study was to investigate the clinical characteristics of AMPS and to assess the effect of sonography-guided trigger point injections (TPI).A total of 100 patients with AMPS from 2012 to 2018 were retrospectively evaluated for clinical characteristics and TPI effects. AMPS was diagnosed using Srinivasan and Greenbaum's criteria, and the TPIs were performed at intervals of 2 to 4 weeks. The Visual Analog Scale (VAS) ratio was calculated by subtracting the final VAS from the initial VAS score and dividing it by the initial VAS score after injections, and the patients were divided into 4 groups: non-responders, mild, moderate, and good responders.The median duration of pain was 12 months, and the median number of hospital visits before TPI was 2. Of the 100 patients, 66 (66%) were categorized as good responders, 11 (11%) as moderate responders, 7 (6.9%) as mild responders, and 16 (15.7%) as non-responders. When the initial and final VAS scores were compared, the sonography-guided injections were found to be effective in alleviating pain (P < .001). Moreover, patients who received the injections 2 or more times tended to have more significant pain reduction than those who received a single injection (P < .001).Patients with AMPS suffer from long-term pain and undergo many hospital visits and diagnostic tests. TPI with lidocaine can be an effective and safe treatment for patients with chronic AMPS.

Anterior Cutaneous Nerve Entrapment Syndrome: Two Case Reports of the Forgotten Diagnosis After Bariatric Surgery

Unexplained abdominal pain is an increasing phenomenon after laparoscopic bariatric surgery, with an occurrence of 7.4%. The pain could be explained by the anterior cutaneous nerve entrapment syndrome (ACNES). However, the incidence of ACNES after laparoscopic bariatric surgery is unclear. We report the cases of two patients with unexplained abdominal pain after laparoscopic bariatric surgery and a significant delay in the diagnosis of ACNES. In both cases, clinical signs of ACNES were demonstrated by a centralized trigger point in the abdominal wall and specific neuropathic aspects during examination. Both patients were temporary pain-free after a diagnostic local lidocaine injection. A neurectomy was performed in both cases, after which they remained pain-free. There was a significant delay (six months and three years, respectively) in the diagnosis of ACNES, and many additional imaging procedures including a diagnostic laparoscopy were performed. ACNES is difficult to diagnose due to its relatively unknown entity.

This case report confirms that the diagnosis of ACNES is still frequently overlooked as a cause of chronic abdominal pain. Earlier diagnosis recognition can probably prevent unnecessary investigations and may improve the quality of life in bariatric patients with unexplained abdominal pain.

Difficult differentiation of a somatic symptom disorder from anterior cutaneous nerve entrapment syndrome (ACNES): a case report

BACKGROUND

Somatization is regarded as psychological or emotional distress in the form of physical symptoms that are otherwise medically unexplained.

CASE PRESENTATION

We report a case of a patient with a somatic symptom disorder (SSD) and depression who was later diagnosed with anterior cutaneous nerve entrapment syndrome (ACNES) when Carnett's test was positive and block anesthesia using trigger point injections dramatically improved the symptom of abdominal pain.

CONCLUSION

We concluded that the differentiation of SSDs, such as psychogenic pain, from ACNES is very difficult. Psychiatrists should be aware of this syndrome.

Anterior Cutaneous Nerve Entrapment Syndrome Possibly Triggered by Oral Contraceptives

We herein report a teenage girl who had been taking oral contraceptive pills for three months and complained of left lower abdominal pain that had continued for two months. A physical examination indicated anterior cutaneous nerve entrapment syndrome (ACNES), although no abnormality was found in various biochemical and imaging examinations. The pain was only transiently ameliorated by trigger-point injection, and neurectomy surgery was eventually effective. Sex steroids can be involved in the progress of local tissue edema causing ACNES. ACNES should be considered in cases of abdominal pain in patients taking oral contraceptives.

Adhesion-induced chronic abdominal pain: a case report on the diagnostic value of Carnett's test

Background

Chronic abdominal pain is a common clinical problem. However, diagnosing chronic abdominal pain often requires detailed diagnostic evaluations in addition to sufficient history taking and physical examination, owing to its uncertain etiology.

Case presentation

We report a case of a 36-year-old man with chronic abdominal pain originating from postoperative adhesions. Postoperative adhesions are common phenomena, and abdominal surgery can cause severe abdominal pain, the source of which can be difficult to detect. Carnett’s test is useful to detect abdominal wall tenderness and to determine the affected abdominal quadrant. Incorporating its use with a detailed chronological clinical history contributes to the improvement of diagnostic accuracy. In addition to the above-mentioned information, attention to subtle imaging findings may provide greater diagnostic accuracy.

Conclusions

Abdominal pain induced by postoperative adhesions was reduced by laparoscopic adhesiolysis. Carnett’s test is an effective tool for evaluating pain and detecting its cause.

Electronic supplementary material

The online version of this article (10.1186/s13256-019-2026-7) contains supplementary material, which is available to authorized users.

Chronic localized back pain due to entrapment of cutaneous branches of posterior rami of the thoracic nerves (POCNES): a case series on diagnosis and management

Introduction and aim

Chronic back pain (CBP) may be caused by a variety of conditions including dysfunctional muscles, ligaments or intervertebral discs, improper movement of vertebral column joints, or nerve root compression. Recently, CBP was treated successfully in a patient having an entrapment of cutaneous branches of the posterior rami of the thoracic nerves, termed posterior cutaneous nerve entrapment syndrome (POCNES). Our aim is to describe clinical presentation, differential diagnosis, and management of patients with such a neuropathic pain syndrome.

Methods

This study analyzed prospectively obtained data from consecutive patients suspected of having POCNES, presenting to two Dutch hospitals between January 2013 and September 2016. Patients received a diagnostic 2–5 mL 1% lidocaine injection just below the thoracolumbar fascia. Pain was scored using a numerical rating scale (0 = no pain to 10 = worst possible pain). A >50% pain reduction was defined as success. A neurectomy was proposed if pain reduction was temporary or insufficient after one to three injections. Long-term treatment effect was determined using a verbal rating scale (VRS; 1 = very satisfied, no pain, to 5 = pain worse).

Results

Fourteen patients (12 women, median age 26, age range 18–73) were diagnosed with POCNES. Eighty-one percent (n=11) reported a >50% pain drop after injection (NRS pain scores of median 8.0 [IQR 7.0–8.0] to median 3.0 [IQR 1.5–3.5], P<0.001). In one patient, repeated injections were successful long-term (VRS score of 2). Two patients declined surgery, whereas the remaining eleven underwent a neurectomy that was successful in seven (64%). A 57% long-term efficacy (median 29 months follow-up, range 5–48, VRS score 1–2) was attained in the entire study population.

Conclusion

POCNES should be considered in the differential diagnosis of chronic localized back pain. A treatment regimen including injections and neurectomy of the specific cutaneous branch results in long-term pain relief in more than half of these patients.

Bilateral distribution of anterior cutaneous nerve entrapment syndrome (ACNES): are clinical features and outcomes comparable to unilateral ACNES?

BACKGROUND AND OBJECTIVES

Mirror-image pain may occur in the presence of a one-sided peripheral nerve lesion leading to a similar distribution of pain on the contralateral side of the body ("mirrored"). Anterior cutaneous nerve entrapment syndrome (ACNES) is a neuropathic pain syndrome due to entrapment of terminal branches of intercostal nerves T7-12 in the abdominal wall and sometimes presents bilaterally. This study aims to address specifics of bilateral ACNES and to determine potential differences in clinical presentation and treatment outcomes when compared with the unilateral form of ACNES.

METHODS

Electronic patient files and questionnaires of a case series of patients who were evaluated for chronic abdominal wall pain in a single center were analyzed using standard statistical methods.

RESULTS

Between June 1, 2011 and September 1, 2016, 1116 patients were diagnosed with ACNES, of which a total of 146 (13%) with bilateral ACNES were identified (female, n = 114, 78 %; median (range) age 36 (1181) years). Average NRS (Numeric Rating Scale; 0-10) scores were similar (median (range) NRS scores 6 (0-10) although peak NRS scores were significantly higher in the bilateral group (9 (5-10) vs 8 (2-10); p=0.02). After a median of 26 months (1-68), the proportion of patients with bilateral ACNES reporting treatment success was 61%.

CONCLUSIONS

One in eight patients with ACNES has bilateral abdominal wall pain. Characteristics are similar to unilateral ACNES cases. Further studies aimed at underlying mechanisms in mirror image pain pathogenesis could provide a more targeted approach in the management of this neuropathic pain.

Treatment of peripheral pain with low-dose local anesthetics by epidermal, epithelial and periosteal application

Objectives

The efficiency of local anesthetics (LAs) in the treatment of peripheral pain is commonly attributed to their capacity to block the axon conduction of sensory nerves. LAs even in non-blocking concentration suppress oscillations of the resting membrane potential. Spiking in sensory neurons is triggered by subthreshold membrane potential oscillations (SMPOs), which reach threshold and is maintained by depolarizing impulse after oscillations. The suppression of these oscillations abolishes sustained afferent discharge in sensory nerves without blocking the axon conduction. In a retrospective observational study, we examined if LAs in low concentration and very small quantities could reduce peripheral pain in patients.

Design

During a period of 2 years, a total of 127 consecutive patients, 43 with cervico-brachial, 12 with intercostal and 72 with lumbo-sciatic pain received an identical treatment, which consisted of LAs applied in 4–8 sessions on average to a fixed set of epidermal, epithelial and periosteal locations. The primary outcome was relief of symptoms measured by verbal analog scales at the end of therapy.

Results

At the end of therapy, 53 (41.7%) of all patients (127) had a complete remission (reduction of pain 100%). Twenty-three patients (18.1%) had a partial remission with >90% reduction of pain and 50 patients (39.4%) had a pain reduction of 30%–90%. One patient did not respond.

Conclusion

LAs in low concentration and small quantities proved to be highly efficient in the treatment of peripheral pain. An almost complete remission could be obtained in a majority of patients. Given the extent of pain reduction achieved, the method of application seems to be of major importance.

Protracted diagnosis of ACNES: a costly exercise

This case report summarizes the course of events leading to diagnosis and eventual repair of anterior cutaneous nerve entrapment syndrome (ACNES) in a 58-year-old female. The time period elapsing from initial symptoms to final operative repair was 9 months. The diagnosis was missed by both medical and surgical specialists despite multiple outpatient appointments, investigative procedures and a battery of laboratory tests. The diagnosis of ACNES was first considered when reviewed by a hernia surgeon and subsequently confirmed following open exploration of the anterior abdominal wall. The nerve was released and pain symptoms resolved. Access to the NHS Scotland ISD register permitted an economic analysis of the diagnostic services utilized for this patient and these totalled nearly £11 500. At a time when the NHS is focused on cost effectiveness, this particular sequence of investigations illustrates a protracted and costly diagnostic pathway.

Peripheral neuropathic mimics of visceral abdominal pain: Can physical examination limit diagnostic testing?

BACKGROUND

The emergency department evaluation of patients with abdominal pain is most appropriately directed at identifying acute inflammation, infection, obstruction, or surgical disease. Doing so commonly involves "routine" (and often extensive) diagnostic imaging and laboratory testing. Benign mimics of serious visceral abdominal pain that can be diagnosed by physical exam and confirmed with local anesthetic injections have been identified over the last century. These syndromes derive from painful irritation of the intercostal nerves by a mobile rib below, or from impingement of the cutaneous branches of those same intercostal nerves as they penetrate the abdominal wall. These peripheral neuropathic mimics of visceral abdominal pain continue to go unrecognized and underdiagnosed.

METHODS

Our purpose is to review the affirmative diagnosis of non-visceral abdominal pain by physical examination.

RESULTS

The consequences of failure to identify these conditions are considerable. In the search for a diagnosis that is literally at the provider's fingertips, patients frequently undergo months to years of fruitless and often invasive diagnostic tests, not uncommonly including unsuccessful surgeries.

CONCLUSIONS

With proper consideration of and appropriate testing for visceral etiologies, a carefully directed physical examination may yield an affirmative diagnosis in a percentage of these common emergency department patients.

Chronic postsurgical pain: current evidence for prevention and management

Chronic postsurgical pain (CPSP) is an unwanted adverse event in any operation. It leads to functional limitations and psychological trauma for patients, and leaves the operative team with feelings of failure and humiliation. Therefore, it is crucial that preventive strategies for CPSP are considered in high-risk operations. Various techniques have been implemented to reduce the risk with variable success. Identifying the risk factors for each patient and applying a timely preventive strategy may help patients avoid the distress of chronic pain. The preventive strategies include modification of the surgical technique, good pain control throughout the perioperative period, and preoperative psychological intervention focusing on the psychosocial and cognitive risk factors. Appropriate management of CPSP patients is also necessary to reduce their suffering. CPSP usually has a neuropathic pain component; therefore, the current recommendations are based on data on chronic neuropathic pain. Hence, voltage-dependent calcium channel antagonists, antidepressants, topical lidocaine and topical capsaicin are the main pharmacological treatments. Paracetamol, NSAIDs and weak opioids can be used according to symptom severity, but strong opioids should be used with great caution and are not recommended. Other drugs that may be helpful are ketamine, clonidine, and intravenous lidocaine infusion. For patients with failed pharmacological treatment, consideration should be given to pain interventions; examples include transcutaneous electrical nerve stimulation, botulinum toxin injections, pulsed radiofrequency, nerve blocks, nerve ablation, neuromodulation and surgical management. Physical therapy, cognitive behavioral therapy and lifestyle modifications are also useful for relieving the pain and distress experienced by CPSP patients.

Pulsed Radiofrequency as a Minimally Invasive Treatment Option in Anterior Cutaneous Nerve Entrapment Syndrome: A Retrospective Analysis of 26 Patients

BACKGROUND

Chronic abdominal pain is occasionally due to entrapped intercostal nerve endings (ACNES, abdominal cutaneous nerve entrapment syndrome). If abdominal wall infiltration using an anesthetic agent is unsuccessful, a neurectomy may be considered. Pulsed radiofrequency (PRF) is a relatively new treatment option for various chronic pain syndromes. Evidence regarding a beneficial effect of this minimally invasive technique in ACNES is lacking. The aim was to assess the effectiveness of PRF treatment in ACNES patients.

METHODS

A series of ACNES patients undergoing PRF treatment between January 2014 and December 2015 in two hospitals were retrospectively evaluated. Pain was recorded prior to treatment and after 6 weeks using a numerical rating scale (NRS, 0 (no pain) to 10 (worst possible pain)). Successful treatment was defined as > 50% NRS pain reduction. Patient satisfaction was scored by patient global impression of change (PGIC, 1 = very much worse, to 7 = very much improved).

RESULTS

Twenty-six patients were studied (17 women, median age 47 years, range 18 - 67 years). After 6 weeks, mean NRS score had dropped from 6.7 ± 1.2 to 3.8 ± 2.3 (P < 0.001). A mean 4.9 ± 1.4 PGIC score was reported by then. Short term treatment success (6 - 8 weeks) was 50% (n = 13, 95% CI: 29 - 71), while 8% was pain-free on the longer term (median 15 months). Median effect duration was 4 months (range 2 - 26).

CONCLUSIONS

PRF is temporarily effective in half of patients with ACNES. PRF is safe and may be favored in neuropathic pain syndromes as nerve tissue destruction is possibly limited. A randomized controlled trial determining the potential additional role of PRF in the treatment strategy for ACNES is underway.

Diagnostic characteristics of anterior cutaneous nerve entrapment syndrome in childhood

Some children suffering from chronic abdominal pain may have an abdominal wall entity such as anterior cutaneous nerve entrapment syndrome. This syndrome is largely suspected on a combination of findings at history and physical examination. The aim is to obtain clues in history and physical examinations in a selected population of children with anterior cutaneous nerve entrapment syndrome. We analyzed all children with abdominal pain visiting our hospital between January 2013 and January 2015. A total of 71 cases were identified (median age 15 years, range 8-17, 77% female). Pain was severe (median 8, range 6-9), stabbing/burning (84%), superficial (88%), aggravated by physical activity (91%), and always in one abdominal area (97%). Hypo-/hyperesthesia (87%) or a positive pinch test (89%) was often found at the skin overlying the painful spot. Increased pain was reported by 97% when the abdominal muscles were tensed (Carnett test). A single anterior rectus sheath block is successful in almost all patients (97%).

CONCLUSION

A combination of typical findings in history and physical examination allows for diagnosing childhood ACNES. What is Known: • Anterior cutaneous nerve entrapment syndrome (ACNES) is often overlooked in chronic abdominal pain. • Pediatric literature on diagnostic work up for ACNES is poor. What is New: • Two third reported treatment delay due to misdiagnosis as functional abdominal pain. • Medical history and physical examination revealed neuropathic pain characteristic in up to 90% of the cases.

Laparoscopic Adhesiolysis in Chronic Abdominal Pain: 15-Year Follow-up Study

BACKGROUND/GOAL

Intra-abdominal adhesions are probably underdiagnosed cause for chronic abdominal pain. Our aim was to evaluate late (>10 y) effect of laparoscopic adhesiolysis on chronic abdominal pain.

STUDY

This was a nonrandomized follow-up study of 68 patients (9 males, 59 females) who suffered chronic abdominal pain. The index operation (laparoscopy and adhesiolysis; n=72 patients) was performed during 1997 to 2001. A quality-of-life questionnaire was asked after the mean follow-up time of 15 years. The hospital records of patients, reoperations for chronic abdominal pain, and full medical history were also reviewed.

RESULTS

Patients reported that adhesion-related pain was abolished or diminished in 90% during 15-year follow-up, but still 28 (41%) complained about some abdominal symptom. One third of the patients used pain-relieving medication or proton-pump inhibitors to relieve their symptoms. Furthermore, 46 (68%) patients had contacted medical service for reexamination of abdominal discomfort and 16 (24%) were reoperated because of some abdominal disease. When the patients with dense adhesions versus no or minimal adhesions were compared in the long term, no difference in the response of pain was noticed after 15 years of adhesiolysis.

CONCLUSIONS

In carefully selected patients suffering from chronic abdominal pain, the positive effect of laparoscopic adhesiolysis stands beyond 15 years after the surgery. Although the patients reported relief of pain they still had various abdominal symptoms.

Diagnostic dilemma: think about anterior cutaneous nerve entrapment syndrome (ACNES) in patients with atypical abdominal pain and Crohn's disease

Chronic abdominal pain can be a difficult diagnostic dilemma. Anterior cutaneous nerve entrapment syndrome (ACNES) is a potential differential diagnosis that should be considered because treatment is both easy and effective. We describe the case of a 51-year-old man presenting with 7 months of right lower quadrant abdominal pain on the background of known Crohn's disease. A circumspect surgical approach and multidisciplinary input was key to making the diagnosis of a nerve entrapment syndrome.

Anterior cutaneous nerve entrapment syndrome with pain present only during Carnett's sign testing: a case report

BACKGROUND

The identification of anterior cutaneous nerve entrapment syndrome is often challenging, due to no widely accepted standard guidelines regarding laboratory and imaging tests for the diagnosis of ACNES.

CASE PRESENTATION

A 77-year-old Japanese man presented with mild lower abdominal pain that had been present for the past 3 years. Physical examination revealed no abdominal pain during palpation, with normal laboratory and imaging testing; therefore, conservative therapy was initiated. However, the abdominal pain continued. Re-examination 16 days later revealed three tender points in accordance with intercostal nerves Th10, Th11, and Th12, with the pain occurring only during Carnett's sign testing. A cutaneous injection of 1% lidocaine was administered, and the abdominal pain was resolved about 30 min later. Based on these results, anterior cutaneous nerve entrapment syndrome was diagnosed.

CONCLUSIONS

It is sometimes hard to diagnose anterior cutaneous nerve entrapment syndrome without testing for Carnett's sign. If patients present with chronic abdominal pain, clinicians should test for Carnett's sign even if no pain is elicited during regular abdominal palpation.

Non-specific abdominal pain remains as the most common reason for acute abdomen: 26-year retrospective audit in one emergency unit

OBJECTIVE

Distribution of diagnoses causing acute abdominal pain (AAP) may change because of population aging, increased obesity, advanced diagnostic imaging and changes in nutritional habits. Our aim was to evaluate the diagnoses causing AAP during a 26-year period.

MATERIALS AND METHODS

This was a retrospective cross-sectional cohort study in one emergency department (ED) covering population about 250,000. All patients admitted to the ED in 1986, 2003 and 2012 were evaluated from hospital electronic database. Demographic data, utilization of diagnostic tests, surgical treatment and discharge diagnosis were analyzed. Statistical data of population aging, obesity and alcohol consumption during 1980-2012 were obtained from national registers.

RESULTS

The AAP patients represented 10-20% of our total ED census. The most common causes of AAP were nonspecific abdominal pain (NSAP, 31-37%), acute appendicitis (11-23%), biliary disease (9-11%), bowel obstruction (5-7%), acute pancreatitis (4-8%) and acute diverticulitis (1-7%). The percentage of NSAP remained highest throughout the study period. Decrease in the number of acute appendicitis (from 23 to 11%; p < .0001), increase in acute diverticulitis (from 1 to 5%; p ≤ .0001) and acute pancreatitis (from 4 to 7%; p = .0273) was observed over time. The utilization of diagnostic imaging increased significantly (CT from 2 to 37% and US from 4 to 38%, p < .0001). Hospital mortality was very low (1-2%).

CONCLUSIONS

NSAP is still the main differential diagnostic problem in the ED. Except acute appendicitis, distribution of specific diagnoses causing AAP remained rather stable through 26-year audit.

DRG Spinal Cord Stimulation as Solution for Patients With Severe Pain Due to Anterior Cutaneous Nerve Entrapment Syndrome: A Case Series

OBJECTIVES

Anterior Cutaneous Nerve Entrapment Syndrome (ACNES) is a debilitating neuropathic pain condition. A small portion of patients do not respond to any currently available treatment modalities. These patients, often young women, might benefit from targeted spinal cord stimulation of the dorsal root ganglion (DRG).

METHODS

This retrospective case series describes five ACNES patients who were referred from a Dutch dedicated tertiary referral center to collaborating sites with extensive experience in DRG stimulation to be implanted with a DRG Axium System (St. Jude/Abbott, IL, USA) in the period of 2013-2016. Numeric pain rating scores at routine 6- and 12-month follow-up visits were analyzed.

RESULTS

Three patients experienced >50% pain reduction at 12 months follow-up. Four patients experienced device-related complications, such as lead dislocation, lead breakage, pain at the battery site, and overstimulation.

CONCLUSIONS

This case series suggests DRG spinal cord stimulation can be safe and effective for some patients with persistent pain due to ACNES.

Treatment response and central pain processing in Anterior Cutaneous Nerve Entrapment Syndrome: An explorative study

BACKGROUND

10-30% of chronic abdominal pain originates in the abdominal wall. A common cause for chronic abdominal wall pain is the Anterior Cutaneous Nerve Entrapment Syndrome (ACNES), in which an intercostal nerve branch is entrapped in the abdominal rectus sheath. Treatment consists of local anaesthetics and neurectomy, and is ineffective in 25% of cases for yet unknown reasons. In some conditions, chronic pain is the result of altered pain processing. This so-called sensitization can manifest as segmental or even generalized hyperalgesia, and is generally difficult to treat.

OBJECTIVE

The aim of this study was to assess pain processing in ACNES patients responsive and refractory to treatment by using Quantitative Sensory Testing, in order to explore whether signs of altered central pain processing are present in ACNES and are a possible explanation for poor treatment outcomes.

METHODS

50 patients treated for ACNES with locally orientated treatment were included. They were allocated to a responsive or refractory group based on their response to treatment. Patients showing an improvement of the Visual Analogue Scale (VAS) pain score combined with a current absolute VAS of <40mm were scored as responsive. Sensation and pain thresholds to pressure and electric skin stimulation were determined in the paravertebral bilateral ACNES dermatomes and at four control areas on the non-dominant side of the body, i.e. the musculus trapezius pars medialis, musculus rectus femoris, musculus abductor hallucis and the thenar. The ACNES dermatomes were chosen to signal segmental hyperalgesia and the sum of the control areas together as a reflection of generalized hyperalgesia. Lower thresholds were interpreted as signs of sensitized pain processing. To test for alterations in endogenous pain inhibition, a conditioned pain modulation (CPM) response to a cold pressor task was determined. Also, patients filled in three pain-related questionnaires, to evaluate possible influence of psychological characteristics on the experienced pain.

RESULTS

Patients refractory to treatment showed significantly lower pressure pain thresholds in the ACNES dermatomes and for the sum of as well as in two individual control areas. No differences were found between groups for electric thresholds or CPM response. Duration of complaints before diagnosis and treatment was significantly longer in the refractory compared to the responsive group, and refractory patients scored higher on the pain-related psychological surveys.

CONCLUSION AND IMPLICATIONS

In this hypothesis-generating exploratory study, ACNES patients refractory to treatment showed more signs of sensitized segmental and central pain processing. A longer duration of complaints before diagnosis and treatment may be related to these alterations in pain processing, and both findings could be associated with less effective locally orientated treatment. In order to validate these hypotheses further research is needed.

REGISTRATION NUMBER

NCT01920880 (Clinical Trials Register; http://www.clinicaltrials.gov).

Chronic Abdominal Wall Pain: An Under-Recognized Diagnosis Leading to Unnecessary Testing

Chronic abdominal wall pain (CAWP) refers to a condition wherein pain originates from the abdominal wall itself rather than the underlying viscera. According to various estimates, 10% to 30% of patients with chronic abdominal pain are eventually diagnosed with CAWP, usually after expensive testing has failed to uncover another etiology. The most common cause of CAWP is anterior cutaneous nerve entrapment syndrome. The diagnosis of CAWP is made using an oft-forgotten physical examination finding known as Carnett's sign, where focal abdominal tenderness is either the same or worsened during contraction of the abdominal musculature. CAWP can be confirmed by response to trigger point injection of local anesthetic. Once diagnosis is made, treatment ranges from conservative management to trigger point injection and in refractory cases, even surgery. This review provides an overview of CAWP, discusses the cost and implications of a missed diagnosis, compares somatic versus visceral innervation, describes the pathophysiology of nerve entrapment, and reviews the evidence behind available treatment modalities.

Prevalence of Anterior Cutaneous Nerve Entrapment Syndrome in a Pediatric Population With Chronic Abdominal Pain

OBJECTIVE

Anterior cutaneous nerve entrapment syndrome (ACNES) is a frequently overlooked condition causing chronic abdominal pain (CAP). The objective of the present study was to investigate the rate of ACNES in a pediatric outpatient cohort with CAP.

METHODS

A cross-sectional cohort study was conducted in a population 10 to 18 years of age consulting a pediatric outpatient department with new-onset CAP during a 2 years' time period. All individuals were identified through a standard hospital registration system. History, physical examination, diagnosis, and success of treatment were obtained in patients who were diagnosed as having ACNES.

RESULTS

Twelve of 95 adolescents with CAP were found to be experiencing ACNES. Carnett sign was positive at the lateral border of the rectus abdominus muscle in all 12. Altered skin sensation was present in 11 of 12 patients with ACNES. Six weeks after treatment (1-3 injections, n = 5; neurectomy, n = 7), pain was absent in 11 patients.

CONCLUSIONS

ACNES is present in 1 of 8 adolescents presenting with CAP to a pediatric outpatient department of a teaching hospital. Simple physical examinational testing allows for the diagnosis. Treatments including nerve blocks or surgery are beneficial in most.

Perforator-Guided Drug Injection in the Treatment of Abdominal Wall Pain

BACKGROUND

Pain from the abdominal wall can be caused by nerve entrapment, a condition called abdominal cutaneous nerve entrapment syndrome (ACNES). As an alternative to surgery, ACNES may be treated with injection of local anesthetics, corticosteroids, or botulinum toxin at the point of maximal pain.

METHOD

The point of maximal pain was marked on the abdominal skin. Using color Doppler ultrasound, the corresponding exit point of perforating blood vessels through the anterior fascia of the rectus abdominis muscle was identified. Ultrasound-guided injection of botulinum toxin in close proximity to the perforator's exit point was performed below and above the muscle fascia.

RESULTS

The technique was used from 2008 to 2014 on 15 patients in 46 sessions with a total of 128 injections without complications. The injection technique provided safe and accurate administration of the drug in proximity to the affected cutaneous nerves. The effect of botulinum toxin on ACNES is beyond the scope of this article.

CONCLUSION

Perforator-guided injection enables precise drug administration at the location of nerve entrapment in ACNES in contrast to blind injections.

Intraperitoneal onlay mesh reinforcement of the abdominal wall: a new surgical option for treatment of anterior cutaneous nerve entrapment syndrome-a retrospective cohort analysis of 30 consecutive patients

BACKGROUND

The aim of the study was to introduce a new surgical treatment for anterior cutaneous nerve entrapment syndrome, a frequently unrecognised disorder in the general population responsible for chronic abdominal wall pain with limited treatment options to date. We hypothesised that intraperitoneal onlay mesh reinforcement could dissipate excessive increases in intra-abdominal pressure and prevent entrapment of the neurovascular bundle.

METHODS

Retrospective cohort analysis was performed between September 2002 and March 2014. All consecutive patients diagnosed with anterior cutaneous nerve entrapment syndrome refractory to conservative treatment (n = 30) underwent laparoscopic intraperitoneal onlay mesh reinforcement of the painful area in the abdominal wall. Planned follow-up took place at 2, 6 and 12 weeks after surgery and at time of analysis (March 2015). Primary outcome was patients' satisfaction after treatment at short and long term (last follow-up) using a verbal rating score as measurement (1 = I am very satisfied; I never experience pain, 2 = I am satisfied; I occasionally experience some pain, 3 = I have improved but experience pain on a regular basis, 4 = I have had no result on this treatment, 5 = my pain is worse after treatment). Scores 1 and 2 were classified as success, and scores 4 and 5 as failure of the treatment.

RESULTS

Thirty patients underwent laparoscopic intraperitoneal onlay mesh reinforcement. None were lost to follow-up (mean 54 ± 44 months, range 12-122, median 38). Short- and long-term success rates were 90 and 71 %, respectfully.

CONCLUSIONS

Intraperitoneal onlay mesh reinforcement of the abdominal wall seems to be a promising option for the treatment of intractable anterior cutaneous nerve entrapment syndrome.

Anterior Cutaneous Nerve Entrapment Syndrome in Children

PURPOSE

The purpose of this manuscript is to report on an entity known as Anterior Cutaneous Nerve Entrapment Syndrome (ACNES) and its relevance to chronic abdominal pain encountered in children.

METHODS

Following institutional review board approval, we retrospectively reviewed patients who underwent operation for presumed ACNES from 2011-2014. Variables reviewed included age, gender, age at surgery, time from onset of pain to surgery, additional medical treatments, and surgery performed. The main outcome measure was amelioration of pain.

RESULTS

Nine patients met the study criteria whereby 7 were female and 2 were male patients. Median age at time of surgery was 14 years (range: 10-19 years) and time from onset of symptoms to surgery was 10 months (range: 0.5-60 months). Eight reported complete resolution of the original symptoms in follow-up appointments. One patient reported new, yet similar symptoms on her opposite trunk.

CONCLUSION

ACNES is a reported cause of chronic abdominal pain that can be managed surgically in the pediatric patient once medical management has been optimized. Close collaboration between surgeons and pain specialists helps identify patients who will benefit from surgical interventions and consideration of this condition could result in more timely pain relief in children. Further studies on a larger scale are needed to determine the long-term outcomes of this procedure.

The approach to chronic pelvic pain in the adolescent

Adolescents present to outpatient and acute care settings commonly for evaluation and treatment of chronic pelvic pain (CPP). Primary care providers, gynecologists, pediatric and general surgeons, emergency department providers, and other specialists should be familiar with both gynecologic and nongynecologic causes of CPP so as to avoid delayed diagnoses and potential adverse sequelae. Treatment may include medications, surgery, physical therapy, trigger-point injections, psychological counseling, and complementary/alternative medicine. Additional challenges arise in caring for this patient population because of issues of confidentiality, embarrassment surrounding the history or examination, and combined parent-child decision making.