Complete Abdominal Wall Disruption With Herniation Following Blunt Injury: Case Report and Review of the Literature
Acute traumatic abdominal wall hernia (TAWH) is a rare type of hernia that occurs after a low- or high-velocity impact of the abdominal wall against a blunt object. With few cases reported, a consensus in diagnosis and management has not been established in the literature. A systematic review of the literature for adult cases of traumatic abdominal wall hernia due to blunt abdominal trauma was undertaken. All original articles were reviewed and data were compiled and tabulated qualitatively. Diagnostic imaging modalities and their reported description of the abdominal wall hernia were detailed correlated with the laparotomy findings. We also report a case of TAWH following blunt abdominal trauma, and describe integration of this management into clinical practice. Fifty-five cases of adult TAWH were found in the English literature. Most hernias contained either small bowel (69%) or large bowel (36%), with 16% of TAWH containing both. Concurrent intra-abdominal injuries were seen in 60% of cases, with an almost equal number of associated bowel (44%) and solid organ (35%) injuries. Twenty percent of diagnosis of TAWH was delayed, ranging from 2 days to 9 years. While TAWH is uncommon, a high index of suspicion is required in patients who present with blunt abdominal trauma. A staging system for TAWH can facilitate appropriate management priorities and treatment. CT scanning is crucial in the diagnosis of TAWH, and aids in definitive management of these patients. The literature supports immediate surgical exploration for most TAWH.
Acute traumatic abdominal wall hernia (TAWH) is a rare type of hernia that occurs after a low- or high-velocity impact of the abdominal wall against a blunt object. The first case was reported in 1906 and since then there has been a paucity of clinical reports.1,2 The incidence of acute post-traumatic hernia, which is rarely encountered in clinical practice, has been estimated at 0.07%.3 This is despite the high incidence of abdominal trauma as presentation to the emergency department.
Historically, there is a low threshold for urgent explorative laparotomy for the management of TAWH because of its strong association with intra-abdominal injury.4 However, with the increasing accuracy of modern computed tomography (CT) in diagnosing visceral injuries and increasing practice for conservative management of solid organs injuries, there is an argument towards managing TAWH conservatively. With few cases reported, a consensus in diagnosis and management has not been established in the literature.
In this study, we perform a thorough review of the literature and characterize all cases of TAWH. We also report our experience with a case of TAWH and discuss a clinical approach in light of the literature findings. Associations were made between diagnostic findings and grading of TAWH, with the need for urgent surgery.
Methods
A systematic review of the literature via a thorough MEDLINE search for adult cases of traumatic abdominal wall hernia due to blunt abdominal trauma was undertaken. All original articles were reviewed and data were compiled and tabulated qualitatively. The keywords search comprised “traumatic abdominal wall hernia” and “handlebar hernia,” and all linkage terms. Cases for inclusion were those 18 years and older, inclusive of all mechanism of injuries. Cases that comprised lumbar defects were excluded. Patient age, gender, and mechanism of injury were recorded. Clinical examination findings were classified as palpable hernia, when it was clearly stated in the article, otherwise ecchymosis when clinical examinations were indeterminate. Grading of abdominal wall disruptions was according to Dennis et al (2009) numeric grading system (see Table 1). Diagnostic imaging modalities and their reported description of the abdominal wall hernia were detailed, correlated with the laparotomy findings.
We also report a case of TAWH following blunt abdominal trauma, and describe integration of this management into clinical practice.
Results
Fifty-five cases of adult traumatic abdominal wall hernia were found in the English literature. The characteristics of each of the cases are tabulated in Table 2. The data were collated and their incidences were presented in Table 3.
The incidence of TAWH was found to be most prevalent in the male population younger than 50 years of age. TAWH happened most frequently as a result of motor vehicle accidents (40%), either as a driver or passenger. Most TAWH presented as either ecchymosis (49%) or a localizing palpable hernia (31%). Locations of TAWH were somewhat equally distributed in all quadrants of the abdomen. The diagnostic imaging modality of choice was computed tomography (CT), which was used in 41 cases (75%). CT scan proved to be a very sensitive diagnostic tool for TAWH, with 90% of initial scan confirming the diagnosis. In 4 cases, only subsequent CT scans were diagnostic of TAWH, with initial earlier CTs not showing observable disruption in abdominal muscle wall. Ninety-six percent of cases reported in the literature had grade V abdominal wall disruption, with the rest presenting with grade IV abdominal wall disruption. Most of the hernia contained either small bowel (69%) or large bowel (36%), with 16% of TAWH containing both. Concurrent intra-abdominal injuries were seen in 60% of cases, with an almost equal number of associated bowel (44%) and solid organ (35%) injuries. Twenty percent of diagnosis of TAWH was delayed, ranging from 2 days to 9 years. Majority of TAWH management were by immediate surgical repair in 42 cases (76%). Delayed hernia repair were performed in 8 cases (15%), while no repair was observed in 2 cases (4%), and 2 other cases did not report their method of abdominal wall repair.
Case Report
A 25-year-old muscular man presented to the emergency department at Sunshine Hospital immediately following blunt abdominal trauma; he had a motor bike accident at approximately 50 km/hour and as a result, he sustained an injury of his abdomen to the handlebar. A few minutes after the accident, a periumblical bulge with surrounding ecchymosis was noticed at the point of impact, which thought to be large rectus sheath hematoma on initial assessment. The patient denied any previous abdominal wall hernia. He complained of diffuse abdominal pain. His primary survey was unremarkable. Abdominal examination revealed tender soft tissue bulge above the umbilicus with superficial ecchymosis measuring approximately 7 × 10 cm, which was thought to be a large rectus sheath hematoma. No other associated injuries were discovered on the rest of his secondary survey. CT abdomen demonstrated ventral abdominal hernia disrupting all the layers and contacting small bowel (Figs. 1 and2). There were no other injuries seen. The patient was taken to theatre for explorative laparotomy. There were no intra-abdominal injuries detected. The hernia was reduced and he underwent early mesh tension-free repair. He remained well and was discharged after 3 days.
Citation: International Surgery 100, 3; 10.9738/INTSURG-D-14-00079.1
Citation: International Surgery 100, 3; 10.9738/INTSURG-D-14-00079.1
Discussion
The term “handlebar hernia” was initially introduced by Dimyan et al in 1980.43 The mechanism of injury for TAWH usually involves a sudden application of a large force to a small area of the abdomen resulting in the disruption of the deeper tissue of the muscle and fascia with or without skin involvement.19 The tangential shearing stresses associated with a sudden elevation in intra-abdominal pressure are thought to be the basic injury mechanism.44 TAWH has been associated with delayed presentation with some postulated theory relating muscle spasm from pain following the trauma initially masking the defect. Ensuing muscle relaxation and raised intra-abdominal pressure from bowel dilatation then thought to exacerbate the muscular defect and developed the herniation. Delayed herniation, as a result of weakening of the abdominal wall from a hematoma or wound infection, have also been reported.31
The frequency of traumatic hernia is considered infrequent if compared with the presentation of blunt abdominal trauma in clinical practice. Dennis et al3 reported an incidence of 0.2% of 3932 CT scans performed after blunt trauma at a level 1 trauma center over a 20-month period. Several attempts have been made to classify traumatic abdominal wall hernia but Dennis et al developed an effective numeric grading system in 2009 (Table 1). Notably the grade 5 herniation (complete abdominal wall disruption with herniation of abdominal contents) for all blunt trauma patients has been estimated at 0.07%. In most reported cases, these cases were managed by early operative repair.
Early recognition and differentiation from hematoma is important and a high index of suspicion and awareness of the condition facilitates treatment and improves outcome. The differential diagnosis is mainly a rectus sheath hematoma and therefore, like others, we believe that high index of suspicion is essential as an accompanying hematoma often confounds the diagnosis.45 CT scan is crucial in the diagnosis of traumatic hernias due to the frequent association with significant intra-abdominal injuries.46 Old age, weak abdominal muscles, and pre-existing hernia are known risk factors for traumatic hernias.47 However, our patient was of a young age, muscular with no pre-existing abdominal wall defect.
Treatment has been controversial and both mesh and primary repair have been successfully performed for treatment of traumatic hernia.24 Traditional layered suture repair has a high recurrence rate, with previous studies measuring up to 54% for incisional hernia repair.30,48,49 Mesh repair has a comparatively lower recurrence rate between 15–30%.48,49 Delay in hernia repair has only been reserved for unstable patients with immediate risk to their lives.37 These studies collectively advocate immediate surgical exploration and repair to avoid complications such as incarceration and strangulation, with no studies offering any reasons otherwise.30,46 Of note, this evidence is largely based on case series, with no level 1 or 2 studies undertaken in such cases.
Conclusion
While TAWH is uncommon, a high index of suspicion is required in patients who present with blunt abdominal trauma. A staging system for TAWH can facilitate appropriate management of priorities and treatment. CT scanning is crucial in the diagnosis of TAWH, and aids in definitive management of these patients. The literature supports immediate surgical exploration for most TAWH.
Axial computed tomography (CT) slice demonstrating abdominal wall disruption of all layers. There is loss of continuity between rectus abdominus muscles, with protrusion of small bowel into the subcutaneous space. No other intra-abdominal injury or free fluid is seen in the abdominal cavity.
Sagittal computed tomography (CT) slice demonstrating protrusion of abdominal contents through a disruption of all layers of the abdominal wall.
Contributor Notes