Don't Forget the Abdominal Wall: Imaging Spectrum of Abdominal Wall Injuries after Nonpenetrating Trauma

Off the wall: incidental paraspinal and pelvic muscle pathology on abdominopelvic imaging

As the use of cross-sectional abdominal and pelvic imaging has increased exponentially in the past several decades, incidental musculoskeletal findings have become commonplace. These are often unrelated to the indication for the examination and are frequently referred to as the "radiologist's blind spot" on these studies. The differential diagnosis for abnormalities of the paraspinal and pelvic musculature is, in many cases, quite different from the anterior abdominal wall muscles. Furthermore, due to their relatively deep location, pathology involving the former muscle groups is more likely to be clinically occult, often presenting only incidentally when the patient undergoes cross-sectional imaging. Effective treatment of diseases of these muscles is dependent on adherence to a diverse set of diagnostic and treatment algorithms. The purpose of this review article is to familiarize the radiologist with the unique pathology of these often-overlooked muscles of the abdomen and pelvis.

The prominent role of percutaneous transarterial embolization in the treatment of anterior abdominal wall hematomas: the results of three high volume tertiary referral centers

PURPOSE

Percutaneous transarterial embolization (PTE) represents a fast, safe and effective option for life-threatening anterior abdominal wall hematomas (AWHs) and those unresponsive to conservative treatment. Our study aims to assess cumulative results of safety, technical and clinical success of PTE performed in three high-volume tertiary referral centers and to evaluate the efficacy of the different embolic materials employed.

MATERIALS AND METHODS

A consecutive series of 124 patients (72.8 ± 14.4 years) with AWHs of different etiology submitted to PTE were retrospectively collected and analyzed. Clinical success, defined as absence of recurrent bleeding within 96 h from PTE, was considered as primary endpoint. The results of the comparison of three groups based on embolic agent employed were also analyzed.

RESULTS

Spontaneous AWHs accounted for 62.1%, iatrogenic for 21.8% and post-traumatic for 16.1% of cases. SARS-CoV-19 infection was present in 22.6% of patients. The most commonly embolized vessels were epigastric inferior artery (n = 127) and superior epigastric artery (n = 25). Technical and clinical success were 97.6 and 87.1%, respectively. Angiographic signs of active bleeding were detected in 85.5% of cases. Four (4%) major complications were reported. The comparison of the three groups of embolic agents (mechanical, particulate/fluid and combined) showed no statistically significant differences in terms of clinical success. SARS-CoV-2 infection was found to be an independent factor for recurrent bleeding and poor 30-day survival.

CONCLUSION

PTE performed with all the embolic agent employed in our centers is a safe and effective tool in the treatment of life-threatening anterior AWH of each origin.

Spontaneous Abdominal Wall Hematoma Treated with Percutaneous Transarterial Embolization: Diagnostic Findings, Procedural Outcome, and Efficacy-A Multicenter Study

Endovascular management of abdominal wall hematomas (AWHs) is now the primary treatment option in hemodynamically stable patients, and it is often preferred to surgical interventions. The purpose of this multicentric study was to assess the safety, technical, and clinical success of percutaneous transarterial embolization (PTAE) of spontaneous AWHs to evaluate the efficacy of blind or empiric embolization compared to targeted embolization and to compare the outcome of the endovascular treatment approach in patients affected by COVID-19 and non-COVID-19 patients. We retrospectively enrolled 112 patients with spontaneous AWHs who underwent PTAE, focusing on signs of bleeding at pre-procedural CTA and DSA. Patients were separated into two groups depending on whether a blind or targeted embolization approach was used. We also divided patients into COVID-19 and non-COVID-19 groups. The mean age of the study population was 68.6 ± 15.8 years. CTA and DSA revealed signs of active bleeding in 99 and 88 patients, respectively. In 21 patients, blind embolization was performed. The overall technical success rate was 99%. Clinical success was obtained in 96 patients (86%), while 16 (14%) re-bled within 96 h. One patient reported a major peri-procedural complication. The comparison between blind and targeted embolization approaches showed no statistically significant differences in the characteristics of groups and technical and clinical success rates. No significant differences were found in the procedural outcome between COVID-19 and non-COVID-19 groups. Our study confirmed that PTAE is effective for treating spontaneous AWHs, even in COVID-19 patients. It suggests that the efficacy and safety of blind embolization are comparable to targeted embolization.

Post-traumatic lateral abdominal wall hernia: a case report

Traumatic abdominal wall hernia (TAWH) also known as blunt abdominal TAWH is uncommon. The clinical diagnosis is difficult. The authors present a case report of posthigh-energy abdominal blunt trauma causing a TAWH.

Case presentation

A 36-year-women, with unremarkable past medical history, was presented to the Emergency Department after a stuck in high-speed two automobiles. She was hemodynamic, respiratory, and neurologically stable. The BMI was 36 kg/m². The abdomen was not distended with an ecchymotic lesion on the right flank. The thoracic abdominal and pelvic computed tomography (CT) scan revealed a rupture in the lateral abdominal wall muscles with a TAWH in the location of the skin ecchymoses. There was no visceral lesion or intraperitoneal fluid. A conservative treatment was indicated. The follow-up was uneventful, with hematoma resorption and no cellulitis or abscess. The patient was discharged after 1 week. An abdominal repair will be planned using a mesh.

Clinical discussion

TAWH is a rare entity. The best imaging modality for diagnosis is the CT scan allowing classification of the hernia and a screen for other injuries. The presence of an isolated TAWH must lower the threshold to closely monitor or to operatively explore, given the high rate of false-negative findings at imaging features.

Conclusion

TAWH should be suspected behind any blunt abdominal trauma with high energy. CT scan and ultrasound were helpful for diagnosis and the only curative treatment is surgery to avoid complications.

Beyond the abdominal and pelvic cavity: abdominal wall and spinal "Aunt Minnies"

Abdominal wall and spinal soft tissue findings are frequently encountered on CT or MR imaging of the abdomen and pelvis. Many of these entities have specific imaging findings, for which a definitive diagnosis can be made without the need for further work up. These abdominal wall and spinal findings may be diagnostically challenging for sub-specialized abdominal radiologists who are unfamiliar with their appearance and appropriate management. This review article describes and illustrates pathognomonic or characteristic abdominal wall and spinal pathologies, which reside outside the abdominopelvic cavity. The cases selected all have findings that allow a confident diagnosis without further imaging or intervention. The cases presented include myonecrosis, intramuscular abscess, myositis, iliopsoas bursitis, Morel-Lavallée lesion, hydrocele of canal of Nuck, Klippel Trenaunay Weber syndrome, neurofibroma with target sign, perineural cysts, filum terminale lipoma, calvarial bone flap, transverse rectus abdominis muscle (TRAM) flap, liposuction, and hidradenitis suppurativa, among others. Although not all-encompassing, this paper will help abdominal radiologists to accurately diagnose a variety of abdominal and pelvic extra-cavitary soft tissue pathologies by identifying key radiologic findings.

Traumatic abdominal wall hernias in the pediatric population: a 13-year institutional review

BACKGROUND

Pediatric traumatic abdominal wall hernias are rare but potentially devastating injuries. Although classically considered to be caused by handlebar injuries from bicycle accidents, our anecdotal experience suggests pediatric traumatic abdominal wall hernias are far more likely to occur following road traffic accidents and have a high association with other significant intra-abdominal injuries.

OBJECTIVE

The purpose of this study was to determine the frequency, mechanisms of injury, and associated injuries of traumatic abdominal wall hernias in the pediatric population.

MATERIALS AND METHODS

This is a retrospective observational cohort study from two large urban level 1 trauma centers. Institutional trauma registries were queried from January 1, 2008, to December 31, 2020, for patients under 18 years of age diagnosed with traumatic abdominal wall hernias, excluding those without initial abdominopelvic CT imaging. Finalized CT reports and images were reviewed to confirm the presence of a traumatic abdominal wall hernia and document any associated secondary injuries. The medical record was reviewed to extract pertinent physical findings, interventions performed, and outcomes. Injury Severity Score (ISS) for each patient was calculated by the trauma registrar.

RESULTS

A total of 19 patients with TAWH met inclusion criteria, with an overall frequency of 0.095% and a mean age of 10.6 years (range 3-17). Eleven patients were male (57.9%) with a mean ISS of 18.6 (range 1-48, including 63.2% with ISS > 15). The most common mechanism of injury was motor vehicle collision (N = 11, 57.9%) followed by bicycle accident (N = 3, 15.8%). A total of 17 (89.5%) had associated injuries, including 11 (57.9%) with intestinal injuries, 5 (26.3%) with pelvic fractures, 4 (21.1%) with femur fractures, 3 (15.8%) with splenic injuries, 3 (15.8%) with kidney injuries, and 3 (15.8%) with Chance fractures of the lumbar spine. All patients required surgery for the traumatic abdominal wall hernias and associated injuries.

CONCLUSION

Pediatric traumatic abdominal wall hernias are more likely to be seen following motor vehicle collisions, with a majority (89.5%) having associated injuries, most frequently to the bowel (57.9%). Handlebar injuries were seen in a minority of patients (15.8%) and were less likely to be associated with additional injuries.

CLINICAL IMPACT

Pediatric patients with a traumatic abdominal wall hernia on admission CT should be thoroughly evaluated for bowel injuries, especially in the setting of a motor vehicle collision.

US and MRI of Pelvic Tendon Anatomy and Pathologic Conditions

The bony pelvis serves as the attachment site for a large number of powerful muscles and tendons that drive lower extremity movement. Organizing the pelvic tendons into groups that share a common function and anatomic location helps the radiologist systematically evaluate these structures for injury, which can be caused by repetitive stress, acute trauma, or failure of degenerated tissues. Tears of the anteromedial adductors around the pubic symphysis and anterior flexors traversing anterior to the hip principally affect younger male athletes. Tears of the lateral abductors and posterior extensors are more common in older individuals with senescent tendinosis. The deep external rotators are protected and rarely injured, although they can be impinged. Imaging of the pelvic tendons relies primarily on US and MRI; both provide high spatial and contrast resolution for soft tissues. US offers affordable point-of-care service and dynamic assessment, while MRI allows simultaneous osseous and articular evaluation and is less operator dependent. While the imaging findings of pelvic tendon injury mirror those at appendicular body sites, radiologists may be less familiar with tendon anatomy and pathologic conditions at the pelvis. The authors review pertinent anatomy and imaging considerations and illustrate common injuries affecting the pelvic tendons. Online supplemental material is available for this article. ^©RSNA, 2022.

Ten-year incidence and treatment outcomes of closed degloving injuries (Morel-Lavallee lesions) in a level 1 trauma centre

INTRODUCTION

Morel-Lavallée lesions (MLL), also referred to as closed degloving injuries, result from traumatic shearing forces with separation of the subcutaneous fat from the underlying fascia. The aim of this study was to determine the incidence and treatment of MLLs at a level 1 trauma centre.

METHODS

Single-centre retrospective cross-sectional study of consecutive patients with an imaging diagnosis of a Morel-Lavallee lesion from 1/1/2010-31/12/2019. Demographic data, mechanism of injury, volume of lesion, management and outcome data were collated.

RESULTS

Sixty-six MLLs were identified in 63 patients (64% Male) with a median age of 49.5 years (19-94 years). Mechanism of injury were road traffic accidents in the majority (66%). Median injury severity score (ISS) was 17 (range 1-33). Patients on oral anti-coagulants had significantly larger lesions (181.9 cc v 445.5 cc, P = 0.044). The most common lesion location was the thigh (60.5%). Patients that underwent imaging within 72 h of injury had significantly larger lesions than those imaged more than 72 h after the inciting trauma (65 cc v 167 cc, P < 0.05). Management data were documented in 59% of lesions (39/66) in which 66.6% (n = 26) had invasive treatment. In the 31 patients where follow-up was available, 64.5% (n = 20) were persistent but decreasing in size. There was no significant difference in follow-up size for those who had invasive compared to conservative treatment (P = 0.3).

CONCLUSION

The diagnosis of MLL should be considered for soft-tissue swelling in the context of shearing trauma. A variety of management options have been employed, with good overall outcomes.

Defining Endotheliopathy in Murine Polytrauma Models

INTRODUCTION

"Endotheliopathy of trauma" is recognized as endothelial dysfunction following traumatic injury leading to poor patient outcomes. Acute post-traumatic disruptions in endothelial cell function have been associated with profound physiologic, hemodynamic, and coagulation derangements. The goal of this study was to define the generation and extent of endotheliopathy in murine polytrauma models by evaluating the post-traumatic release of serum biomarkers of ongoing cellular injury.

METHODS

Mice were randomized to undergo moderately severe concussive TBI by weight drop, 60-min hemorrhagic shock to MAP 25 mmHg with subsequent resuscitation with Lactated Ringer's, submandibular bleed (SMB), and/or midline laparotomy with rectus muscle crush. Mice were sacrificed at 1, 4, or 24 h for serum biomarker evaluation.

RESULTS

Serum biomarkers revealed differential timing of elevation and injury-dependent release.At 24 h, soluble thrombomodulin was significantly elevated in combined TBI + shock + lap crush compared to untouched, and shock alone. Syndecan-1 levels were significantly elevated after shock 1 to 24 h compared to untouched cohorts with a significant elevation in TBI + shock + lap crush 24 h after injury compared to shock alone. UCHL-1 was significantly elevated in shock mice at 1 to 24 h post-injury compared to untouched mice. UCHL-1 was also significantly elevated in the TBI + shock cohort 24 h after injury compared to shock alone. Hyaluronic acid release at 4 h was significantly elevated in shock alone compared to the untouched cohort with further elevations in TBI + shock + lap crush and TBI + shock compared to shock alone at 24 h. Hyaluronic acid was also increased in lap crush and laparotomy only cohort compared to untouched mice 24 h after injury.

CONCLUSIONS

A murine model of polytrauma including TBI, hemorrhagic shock, and laparotomy abdominal crush is a reliable method for evaluation of endotheliopathy secondary to trauma as indicated by differential changes in serum biomarkers.

Efficacy of Percutaneous Transarterial Embolization in Patients with Spontaneous Abdominal Wall Hematoma and Comparison between Blind and Targeted Embolization Approaches

Background: Endovascular treatment of abdominal wall hematomas (AWHs) has been increasingly used when conservative treatments were not sufficiently effective, and it is often preferred to surgical interventions. The aim of our study was to evaluate the safety and technical and clinical success of percutaneous transarterial treatment of AWH and to evaluate the efficacy of blind embolization compared to targeted embolization. Materials and Methods: We retrospectively enrolled 43 patients (23 men and 20 females) with spontaneous AWH who underwent digital subtraction angiography (DSA) and embolization, focusing on the presence of signs of bleeding at pre-procedural CT-Angiography (CTA) and at DSA. Furthermore, we divided patients into two groups depending on blind or targeted embolization approaches. Results: The mean age of the study population was 71 ± 12 years. CTA revealed signs of active bleeding in 31 patients (72%). DSA showed signs of active bleeding in 34 patients (79%). In nine patients (21%), blind embolization was performed. The overall technical success rate was 100%. Clinical success was achieved in 33 patients (77%), while 10 patients (23%) rebled within 96 h, and all of them were re-treated. No major peri-procedural complication was reported. The comparison between blind and targeted embolization showed no statistically significant differences for characteristics of groups and for clinical success rates (78% and 77%, respectively, −p = 0.71). The technical success was 100% in both groups. Conclusions: Our study confirms that transarterial embolization is a safe and effective option for the treatment of spontaneous AWHs, and it suggests that the efficacy and safety of blind embolization is comparable to non-blind.

Pre- and postsurgical imaging findings of abdominal wall hernias based on the European Hernia Society (EHS) classification

Abdominal wall hernias are common and can present as technical challenges to surgeons. When large, hernias diminish quality of life. Various classifications of incisional hernias have been proposed; however, there are many terms, sometimes causing confusion (1). Radiologists must know the normal anatomy of the abdominal wall, the CT protocol, and what if any maneuvers can be performed to better identify an abdominal wall defect. The description of the radiological approach for primary and incisional wall hernias is based on the 2007 European Hernia Society classification, with particular emphasis on presurgical and postsurgical imaging findings. This classification provides a simple and reproducible method to describe hernias to offer proper surgical management. We highlight this classification so that radiologists and surgeons can have a unified language.

Post-partum rectus sheath hematoma complication: case report

Pregnancy, surgery, and trauma are known risk factors for the development of rectus sheath hematomas (RSHs). The exact incidence of RSH during pregnancy is unknown, however this disease carries a risk of complication and even mortality. The role of infection in this condition is less known with only a few reported case studies in medical literature. In our case a 26-year-old G4P2113 1-month status post cesarean section presented with 2 weeks of progressive lower abdominal pain after her 50-pound daughter jumped on her. Upon further work up a computed tomography (CT) scan found a 15-cm RSH. Expectant management is the recommended first line of treatment, however, this failed after the patient presented with signs and symptoms of infection. An exploratory laparotomy was performed that had evidence of necrotizing fasciitis of the rectus muscle and subcutaneous tissue. This is a very atypical presentation of a RSH complicated with myonecrosis after a cesarean delivery. Review of the medical literature shows appropriate work up and diagnosis of RSH in pregnant patients is critical for early intervention. Furthermore, while conservative treatment is typically appropriate for non-pregnant patients it may not be sufficient for pregnant and post-partum patients. Improved understanding of this condition will result in heightened clinical suspicion, faster intervention, and more appropriate treatment. This is critical to reducing the maternal and perinatal morbidity/mortality associated with this disease.

Traumatic abdominal wall injuries-a primer for radiologists

Traumatic abdominal wall injuries encompass a broad clinical and radiological spectrum and are identified in approximately 9% of blunt trauma patients. The most severe form of abdominal wall injury-a traumatic abdominal wall hernia-is seen in less than 1.5% of blunt abdominal trauma patients. However, the incidence of concurrent intra-abdominal injuries in these patients is high and can result in significant morbidity and mortality. Although the diagnosis of abdominal wall injuries is typically straight forward on CT, associated injuries may distract the interpreting radiologist in more subtle cases. Thus, it is important for the radiologist to identify abdominal wall injuries and their associated injuries on admission CT, as these injuries typically require surgical correction early in the course of their management. Untreated abdominal wall injuries subject the patient to increased risk of delayed bowel incarceration and strangulation. Therefore, it is important for the radiologist to be knowledgeable of injuries to the abdominal wall and commonly associated injuries to provide optimal patient triage and expedite management.

Musculoskeletal ultrasound for traumatic and torsional alterations

The sonographic appearance of soft tissue can be altered by trauma and positional change with torsional stress. This creates challenges for ultrasonographic interpretation, because most descriptive literature and standard instructional references are displayed in anatomically neutral or other conventional positions. Knowledge of anatomic alteration and changes in sonographic appearance with torsional stress is essential for accurately assessing soft tissue abnormalities in conditions of spasticity, traumatic and post-surgical changes, and other conditions that distort musculoskeletal relationships. A systematic scanning approach to these alterations is needed for accurate diagnostic interpretation, optimizing electrode placement for electrodiagnostic techniques, effective needle placement for therapeutic ultrasound-guided procedures, and even planning for restorative surgery. This review describes expected positional changes of normal structures with torsional alteration, as well as sonographic recognition of scars, burns, hematomas, fat layer fracture, Morel-Lavallee lesions, abscesses, foreign bodies, myotendinous lesions, muscle injury and denervation, and traumatic peripheral nerve injury.

Imaging of Abdominal Wall Masses, Masslike Lesions, and Diffuse Processes

Abdominal wall masses, masslike lesions, and diffuse processes are common and often incidental findings at cross-sectional imaging. Distinguishing among these types of masses on the basis of imaging features alone can be challenging. The authors present a diagnostic algorithm that may help in distinguishing different types of abdominal wall masses accurately. Hernias may mimic discrete masses at clinical examination, and imaging is often ordered for evaluation of a possible abdominal wall mass. Once a discrete mass is confirmed to be present, the next step is to determine if it is a fat-containing, cystic, or solid mass. The most common fat-containing masses are lipomas. Fluid or cystic masses include postoperative abscesses, seromas, and rectus sheath hematomas. Solid masses are the most common abdominal wall masses and include desmoid tumors, sarcomas, endometriomas, and metastases. Multiple masses and other diffuse abdominal wall processes are often manifestations of an underlying condition or insult. The most frequently found diffuse processes are multiple injection granulomas from administration of subcutaneous medication. This article offers an algorithmic approach to characterizing abdominal wall masses on the basis of their composition and reviews abdominal wall diffuse processes. Online supplemental material is available for this article. ^©RSNA, 2020.

The First Reported Case of Morel-Lavallée Lesion and Traumatic Abdominal Wall Hernia: A Case Report and Review of the Literature

BACKGROUND First described in 1863 by French surgeon Victor-Auguste-François Morel-Lavallee, the Morel-Lavallee lesion (MLL) is a closed traumatic soft-tissue degloving injury. These lesions most commonly occur following motor vehicle collisions (MVCs). The pathophysiology stems from a shearing force that causes separation of the soft tissue from the fascia underneath, which disrupts the vasculature and lymphatic vessels that perforate between the tissue layers. Timely diagnosis and treatment are imperative, as a delayed diagnosis can lead to complications. However, at present there is no universally accepted treatment algorithm. CASE REPORT A 60-year-old morbidly obese woman presented after being involved in an MVC. She complained of abdominal tenderness in the right lower quadrant, with no evidence of peritonitis. Cross-sectional imaging revealed hemoperitoneum and a traumatic posterior abdominal wall/lumbar hernia on the right, with multiple contusions in the subcutaneous abdomen. The patient was taken to the operating room and underwent an exploratory laparotomy that revealed a large abdominal Morel-Lavallee lesion (MLL) along with a traumatic abdominal wall hernia (TAWH). There was also a mesenteric avulsion injury with an associated ileocecal injury. The patient underwent resection of the involved bowel, with primary anastomosis, debridement of the abdominal wall degloving injury, and expectant management for the hernia defect. She recovered from the injuries and was doing well when followed up in the clinic, with follow-up to repair the hernia in the near future. CONCLUSIONS More research is needed to provide surgeons with evidence-based standardized therapies for dealing with these rare pathologies to ensure optimal patient outcomes.

CT findings of severe burn injuries after a motor vehicle collision: a case report

Severe burn injuries can complicate management of polytrauma. While CT is the primary imaging modality for evaluation of trauma injuries, CT findings of severe burn are rarely reported. A 31-year-old female was brought to the emergency department after motor vehicle collision in which she sustained a burn injury from contact with the vehicle muffler. Her initial trauma workup was notable for full-thickness burns to her left abdominal wall among other injuries. CT scan showed skin thickening and extensive stranding involving the whole layer of subcutaneous soft tissue. The deep fascia and underlying muscle layer were free from burn injuries. Identification of this finding on the CT scan helps establish appropriate care.