The most commonly injured intra-abdominal organs in penetrating trauma are the small bowel and the colon. One prospective study of 309 gunshot wounds to the anterior abdomen demonstrated that the small bowel was injured in 37.7% of patients and the colon in 27.3%, followed in frequency by the liver (27.2%), the kidney (15.7%), the diaphragm (15.2%), the abdominal vasculature (14.3%), the stomach (12.4%), the spleen (6.9%), and the bladder (6.5%).¹

The goal of the evaluation of penetrating abdominal trauma is to reliably detect intra-abdominal organ injury requiring operative management while avoiding unnecessary celiotomy. The obvious benefits of early detection must be balanced against the morbidity associated with unnecessary operative intervention.

Before the 1960s, celiotomy was the gold standard for the evaluation of all cases of penetrating injuries to the abdomen. However, negative explorations are associated with significant morbidity. In one prospective study of 938 trauma patients undergoing celiotomy, unnecessary surgery was performed in 254 patients for an overall unnecessary celiotomy rate of 27%.² This rate was similar between patients with stab wounds and gunshot wounds. Forty-one percent of these patients developed a complication attributed to the negative celiotomy. The complications included atelectasis (15.3%), postoperative hypertension requiring medical management (11.0%), pleural effusion (9.8%), pneumothorax (5.1%), prolonged ileus (4.3%), pneumonia (3.9%), surgical wound infection (3.2%), small bowel obstruction (2.4%), and urinary tract infection (1.9%).

Approximately 20% of patients who did not have an associated injury and underwent completely negative celiotomy experienced a perioperative complication.² Subanalysis of this data revealed that the mean length of stay was 8.2 and 5.5 days, respectively, for patients with gunshot wounds and stab wounds after negative celiotomies. The overall mean length of stay for patients who had no associated injuries and on whom completely negative celiotomies were performed was 4.7 days. Postoperative complications increased this mean length of stay to 9 days.³ This increased length of stay was associated with significantly higher hospital costs compared to those patients with similar wounds that were managed nonoperatively.

Patients who are hemodynamically unstable or who have diffuse abdominal tenderness after penetrating abdominal trauma should undergo emergent operative exploration. A patient with an unreliable clinical examination
due to severe head injury, spinal cord injury, severe intoxication, or the need for sedation or intubation should have operative exploration or undergo further diagnostic evaluation for the presence of an intraperitoneal injury.⁴

Stab wounds to the abdomen are associated with a lower incidence of intra-abdominal injury than gunshot wounds. On the basis of this observation, there has been a shift toward selective nonoperative management of anterior abdominal stab wounds since the 1960s, and cautious conservatism is now the standard of care. Evidence suggests that selective operative management of stab wounds based on physical examination, local wound exploration, laparoscopy, computed tomography (CT), or some combination of these diagnostic modalities is safe and effective. Because no single technique has been proved to be adequate for all patients with anterior abdominal stab wounds, no standard of care regarding the most appropriate management exists.

There are some patients with abdominal stab injuries who may qualify for initial nonoperative management based on benign abdominal examination findings. These patients should be closely observed and serial examinations should be performed. In those patients who are selected for initial observation, exploratory celiotomy should be performed if peritonitis develops or an unexplained drop in blood pressure or hematocrit occurs.

Demetriades et al. performed a prospective study of 651 patients with anterior abdominal stab wounds. Patients were selected for operative or nonoperative management based on physical findings alone. Those who presented with peritoneal signs (tenderness, guarding, rebound tenderness, and absent bowel sounds) underwent immediate celiotomy; all other patients were selected for observation with serial physical examinations. These authors found that of the 306 patients who were initially managed nonoperatively only 11 (3.6%) required subsequent operative exploration. Of those who underwent delayed operative management, two patients had negative celiotomies. In total, 27.5% of patients with abdominal stab wounds were successfully managed nonoperatively without any deaths or major complications. The sensitivity of the initial physical examination to detect the need for operative management was 97.1%.⁵ Another group reported similar results in a study of 330 patients with anterior abdominal stab wounds. On the basis of physical examination, they were able to select 176 patients for nonoperative management with three (1.7%) missed injuries.⁶ Physical examination of the patient’s abdomen is highly sensitive and specific for intra-abdominal injury and is extremely cost effective.

Some centers use the presence of peritoneal penetration as an indication for operative management of hemodynamically stable patients with abdominal stab wounds. In cases of obvious peritoneal penetration, such as omental or bowel evisceration, celiotomy is used to completely evaluate the peritoneum for intra-abdominal injury. According to several series, evisceration of any organ is associated with a 75% to 100% incidence of intra-abdominal injury requiring operative management.⁷ In addition, evisceration indicates the presence of a fascial defect large enough to allow bowel herniation and requires repair. Most would agree that omental or hollow viscus evisceration mandates operative evaluation.

For stable patients in whom peritoneal penetration is in question, local wound exploration may be employed to evaluate for penetration of the anterior abdominal fascia. This may be performed in the emergency department using local anesthetic and sterile technique. The wound should be surgically extended to facilitate visualization of the anterior fascia. If fascial penetration is confirmed, celiotomy is performed. Some centers advocate the additional step of laparoscopy to confirm peritoneal penetration before celiotomy is performed. However, even proven peritoneal penetration is not always indicative of organ injury. Some studies report that up to 30% of patients with proven peritoneal penetration do not have significant intra-abdominal injuries and that these patients maybe managed with close observation alone.⁵

The increased use of laparoscopy for the evaluation of peritoneal penetration in anterior abdominal stab wounds is a reflection of its widespread availability and advances in laparoscopic technologies. In one study of 40 laparoscopies performed for penetrating abdominal stab wounds, half of the study patients had laparoscopies that were negative for peritoneal penetration and were able to avoid an unnecessary celiotomy.⁸ Of the 22 patients with peritoneal penetration on laparoscopy, 3 had minor isolated liver injuries that did not require further intervention, 4 had injuries to the left diaphragm that were repaired laparoscopically, and the remaining 15 patients required celiotomy for open repair of intra-abdominal injuries. In total, the use of laparoscopy avoided unnecessary celiotomy in 66% of patients with penetrating abdominal injury. One benefit of this less invasive approach is the shorter length of hospital stay. For those with negative laparoscopy, the length of stay was 2.2 ± 1.1 days compared to 4.0 ± 1.7 days for those patients who underwent open exploration. These findings are similar to those of older studies⁹ that also report negative laparoscopy rates of 50% and significantly shorter hospital stays following laparoscopy.

Laparoscopy has been used successfully in the evaluation of penetrating injuries to the left thoracoabdominal area. It has been shown that these injuries carry an 18% to 35% incidence of contemporaneous injury to the diaphragm.¹⁰,¹¹ Before the availability of laparoscopy, routine open exploration was the gold standard to avoid
missed diaphragmatic injuries. In the early 1990s, studies proved that laparoscopy could be used to avoid the 30% to 65% negative celiotomy rate associated with routine celiotomy for thoracoabdominal injuries.¹⁰,¹¹ One important advantage of laparoscopy in these types of injuries is that it permits both the diagnosis and the repair of diaphragmatic injuries. The disadvantages of the laparoscopic approach are that it is invasive, costly, and it is inadequate for the evaluation of hollow viscus injuries. In addition, laparoscopy requires general anesthesia and carries with it the small, but significant risk of iatrogenic injury during trocar placement.

Helical CT has long been used for the evaluation of hemodynamically stable patients with blunt abdominal trauma. With its increasing availability, speed, and sensitivity, CT is emerging as a useful tool in the evaluation of penetrating abdominal trauma. Although several studies conclude that CT scan can accurately detect bowel injury, peritoneal penetration, and need for operative intervention, these studies are limited in that they are nonrandomized, retrospective reviews, and not limited to penetrating anterior abdominal wounds.¹²,¹³ One potential application of CT scan in penetrating trauma is that it may be a useful adjunct in the evaluation of patients with reassuring abdominal examinations to allow for early discharge of patients with benign physical findings and negative CT scans.

Although selective nonoperative management is practiced extensively for abdominal stab wounds, routine celiotomy is still considered the standard of care for anterior abdominal gunshot wounds in the combat theater and in many trauma centers. One argument for routine exploration is that gunshot wounds carry with them a higher incidence of intra-abdominal organ injury than stab wounds, ranging from 30% to 70%.¹

One large retrospective review by Velmahos et al. of 1,405 patients with anterior abdominal gunshot wounds from a single institution reported the results of their nonoperative management strategy. Of these patients, 484 (34%) were initially selected for nonoperative treatment based on stable vitals signs and benign abdominal examinations. Within the nonoperative group, 65 patients (5%) required delayed celiotomy, and of these patients, 17 (26%) had negative celiotomies. The average time to delayed operative management was 6 hours from admission and there were no deaths among the patients treated nonoperatively. In all, 30% of patients with anterior abdominal gunshot wounds were successfully managed without operative exploration.¹⁴ This is similar to the successful nonoperative management rate seen in studies of anterior abdominal stab wounds.

Blunt trauma is the most common mechanism of injury seen in the United States, and is most frequently caused by motor vehicle collision, motorcycle accidents, falls, assaults, and pedestrians struck. Colon and small bowel injuries are found in 1.2% and 0.3% of blunt trauma patients respectively.¹⁵ Delay in diagnosis of >8 hours has been shown to increase morbidity and mortality directly attributable to the missed bowel injury. Mortality and complication rates were found to increase in parallel with time to operative intervention.¹⁶

Blunt traumatic bowel injuries are notoriously difficult to diagnose. Abdominal pain and peritonitis may take up to 6 to 8 hours to develop. One multi-institutional analysis demonstrated that 13% of patients with perforating small bowel injuries had normal abdominal CT scans preoperatively.¹⁶ As nonoperative management of solid organ injuries becomes the standard of care, there is an increased risk of delayed diagnosis of blunt small bowel injuries.

In a review of the Pennsylvania trauma registry, Nance et al. showed a predictive relationship between solid and hollow viscus injuries in blunt abdominal trauma patients. The authors reviewed 3,089 patients who suffered a solid organ injury and found that 9.6% also had a hollow viscus injury. They further examined the number of solid organs injured and the percent of these patients who suffered hollow viscus injury. Among the 79% of patients with a single solid organ injury there were 7.3% patients with a hollow viscus injury. Of the patients with two solid organs injured, 15.4% also had a hollow viscus injury. Finally, in those patients with three or more solid organs injured, 34.4% also suffered a concomitant hollow viscus injury. The authors advocate a higher index of suspicion and early operative intervention for patients who suffer blunt abdominal trauma and have multiple solid organ injuries.¹⁷