Chronic Intermittent Intestinal Obstruction From a Seat Belt Injury

Southern Medical Journal 2001
Chronic Intermittent Intestinal Obstruction From a Seat Belt Injury
Janet R. Harrison, MD, Michael O. Blackstone, MD, Thomas Vargish, MD, Arunas Gasparaitis, MD, Division of Gastroenterology, University of Chicago Hospitals, Chicago, Ill

Abstract

Most patients with intestinal obstruction have had previous surgery. Rarely, the development of adhesions and resulting small bowel obstruction is attributed to previous intra-abdominal trauma. We present the case of a young man, without a history of surgery, who had been a restrained driver in a motor vehicle crash. Seven years later, the patient had an intermittent partial small bowel obstruction that recurred over the next 5 years. We review the pathophysiology and epidemiology of similar occurrences, as well as diagnostic options. [South Med J 94(5):499-501, 2001. © 2001 Southern Medical Association]
Introduction
Intra-abdominal adhesions cause most mechanical small bowel obstructions.[1,2] Most adhesions are due to previous intra-abdominal surgery.[2,3] In patients without a surgical history, intra-abdominal adhesions have rarely been attributed to blunt abdominal trauma.[1,2,4,5]
We report a case of a young man who was the restrained driver in a car crash. He had no history of laparotomy or intra-abdominal disease. After a protracted course of recurrent pain, adhesional intermittent partial small bowel obstructions were diagnosed. Abdominal trauma may be an under-recognized cause of obstructing intestinal adhesions.
Case Report
This 33-year-old man had had intermittent abdominal pain for 5 years. Approximately once a year, he had an episode of lower abdominal "tightening" and "spasm." The symptoms lasted 10 to 24 hours and were associated with nausea and vomiting. He limited his diet to clear liquids, toast, and crackers until the pain remitted. Between these episodes, he had no gastrointestinal symptoms.
Twelve years before this presentation, he had been the restrained driver in a motor vehicle crash, which had caused abdominal wall contusions, transient microscopic hematuria, a clavicular fracture, and a pneumothorax. He had not required surgery, and computed tomography had not been done. He had no other medical history; he denied surgery, abdominal radiation, intra-abdominal infection, and inflammatory diseases of the bowel.
Previous studies included small bowel radiography, barium enema, magnetic resonance imaging (MRI) of the abdomen, colonoscopy, urine porphyrin testing, and stool studies for ova and parasites. These were all unremarkable. The patient was intermittently treated with famotidine, dicyclomine, hyoscyamine, and omeprazole. There was no change in frequency, duration, or severity of symptoms. Family history and social history were unremarkable.
The patient was a well-appearing tall, thin man. He was afebrile and normotensive, and findings on physical examination, including the abdominal and rectal examinations, were normal.
To further investigate the source of pain, an enteroclysis and a Meckel's scan were done (while the patient was asymptomatic). Results of both were normal.
Four months after these tests, the abdominal pain recurred. While he was still symptomatic, another enteroclysis was done, which showed kinking of the small bowel at an acute angle. The contrast material moved slowly and pooled. This was diagnostic of an adhesional small bowel obstruction
At laparoscopy
Extensive small bowel adhesions were found, and several discrete bands were causing kinking in the distal jejunum (Fig 2). Lysis of adhesions was done during the laparoscopy. The bowel was normal in appearance, without stenosis, stricture, or inflammation. After 1 year of follow-up, the patient is well and has had no further episodes of abdominal pain.
Discussion
Adhesions from previous surgery cause most small bowel obstructions.[2,3] Combining the data from three published studies yielded a total of 1,730 patients with adhesional small bowel obstructions.[2,6,7] The vast majority of patients had a history of previous surgery, and only 218 patients (12.6%) had no surgical history. In 129 (60%) of the nonsurgical patients, an etiology was identified -- most often tuberculous peritonitis, a history of intra-abdominal inflammation, or a history of pelvic inflammatory disease. In one patient, the adhesions were attributed to abdominal trauma, occurring 3 weeks before the development of obstruction. In 89 (40%) of the nonsurgical patients, there was no identifiable cause for the adhesions.[2,6,7]
In our case, a restrained driver in a motor vehicle crash had significant abdominal trauma, causing abdominal wall ecchymoses and microscopic hematuria at the time of the crash. Seven years later, intra-abdominal adhesions caused intermittent small bowel obstructions with associated abdominal pain. Although the motor vehicle crash and adhesional small bowel obstruction may be coincidental in our patient, there is no other explanation for the development of adhesions. Our case, therefore, suggests that the intra-abdominal trauma may have caused the development of adhesions and subsequent small bowel obstruction. A subset of patients with "idiopathic" adhesions may have had a history of remote abdominal trauma.
In 1962, Garrett and Braunstein first described the "seat belt syndrome," which encompassed a spectrum of intra-abdominal injuries caused by the seat belt during impact. In one study, 5% to 15% of patients sustaining blunt abdominal trauma had intestinal injury occurred. The intestine is, in fact, the third most commonly injured intra-abdominal organ in the seat belt syndrome. Relatively fixed portions of bowel, such as the proximal jejunum and distal ileum, are more susceptible to injury.[5,10,11] The mobile portions are able to escape the highest pressure and the resultant damage.[11]
Motor vehicle crashes cause intestinal injury by several mechanisms. As an individual is propelled forward upon impact, the seat belt or buckle inflicts pressure -- throwing the intestine against the vertebral column and causing a contusion.[4,12-14] Also, rapid deceleration may shear fixed ligaments and mesenteric attachments.[12-16]
Surgery and trauma result in peritoneal injury, the impetus for the development of adhesions. After surgery, the peritoneal surface is denuded and the microvasculature is disrupted, releasing a serosanguineous exudate that is followed by the formation of a fibrinous bridge.[3,17,18] Since fibrinolysis requires an adequate blood supply, tissue injury in an avascular milieu is associated with diminished fibrinolysis and a persistent fibrinous bridge.[3,17] Collagen is deposited 4 to 5 days later, and permanent adhesions result.[18] Since abdominal trauma is another cause of peritoneal injury, it is a logical supposition that adhesions could form in this scenario.
The seat belt syndrome includes acute intestinal injury, as well as the less common delayed small bowel obstruction.[5,12-16,19,20] Most patients have symptoms 2 to 3 weeks after a crash and go to their physician 4 to 18 weeks after the trauma, though presentation has been delayed as long as 18 years.[12,15] The common symptoms of abdominal distention, pain, and vomiting mimic postoperative obstruction.[16] At the time of surgical exploration, strictures, previous perforations, and adhesions have been identified as the cause of obstruction in patients with posttraumatic small bowel obstructions.[4,14-16,20] In one case report, a motor vehicle crash caused abdominal pain and an adhesional small bowel obstruction without structural abnormalities of the intestine.
In our case, a motor vehicle crash presumably caused an intestinal contusion, eventually resulting in adhesion formation and intermittent obstruction. Any source of severe blunt abdominal trauma, such as contact sports or biking accidents with resultant peritoneal injury, could cause adhesions by the same mechanism; peritoneal contusion associated with a decrease in fibrinolysis can result in the development of adhesions. Perhaps unrecognized "trauma" accounts for a portion of unexplained adhesional obstructions.[2,6,7] Recurrent obstructive symptoms should therefore prompt the clinician to take a thorough history of abdominal trauma.[5,21]
This case also portrays the difficulty of diagnosing an intermittent partial small bowel obstruction. Enteroclysis correctly diagnoses an adhesive small bowel obstruction in as many as 87.8% of patients.[22] False-negative studies occur and are more likely if the enteroclysis is done when the patient is asymptomatic.[22] Johnson et al[22] advocated the use of radiopaque markers, which collect proximal to the obstruction, to unmask adhesive obstructions. Results of our patient's initial enteroclysis were entirely normal, even on subsequent review. In comparison, when he was symptomatic, the study revealed a high density of contrast material proximal to an obstructing band, and the diagnosis of partial small bowel obstruction was made.