Hollow viscus blunt abdominal trauma in children

INTRODUCTION — This topic will review blunt hollow visceral injuries in children, including mesenteric injury, duodenal hematoma, and perforation of the stomach, small intestine, and colon. Evaluation and management of traumatic liver, pancreas, and splenic injuries in children and bowel injuries associated with rectal foreign bodies are discussed separately. (See "Liver, spleen, and pancreas injury in children with blunt abdominal trauma" and "Rectal foreign bodies", section on 'Complications'.)

EPIDEMIOLOGY — In children, blunt trauma accounts for more than 90 percent of abdominal injuries. Although the incidence of hollow viscus injuries in all blunt trauma patients is <5 percent, these injuries comprise 15 to 20 percent of pediatric intra-abdominal injuries according to large multicenter reviews of children with intra-abdominal trauma [1,2]. Small bowel injury, especially to the jejunum or ileum, is the most frequent, followed by duodenal, colon, and gastric injury [2,3]. The most common mechanism for these injuries is direct blunt-force trauma, such as from a motor vehicle collision, sports injury, assault or physical child abuse [4], or fall onto a bicycle handlebar or other object. Seat belts are an important contributor to hollow viscus injuries caused by motor vehicle collisions [5]. (See 'Pertinent anatomy' below and 'Mechanism of injury' below.)

Although infrequent and often subtle at presentation because they do not lead to hemodynamic instability, hollow viscus injuries contribute to significant morbidity and mortality [3,6]. Operation is almost always required for these injuries in contrast to most other abdominal injuries, which are primarily managed nonoperatively. Delayed presentation or diagnosis can lead to intra-abdominal sepsis and death, and even timely operation carries with it significant risk of surgical site infection and intra-abdominal abscess [6].

PERTINENT ANATOMY — The anatomic location determines the likelihood of injury to specific portions of the gastrointestinal tract:

●Small intestine – The anterior location of the jejunum and ileum puts them at highest risk for hollow viscus injury, especially from a seat belt injury mechanism [2,3]. These injuries are most commonly perforations or mesenteric injuries that are sometimes referred to as "bucket handle" injuries, referring to the portion of intestine that is avulsed from the mesentery [7].

The duodenum is less commonly injured due to its retroperitoneal location, accounting for under 5 percent of all abdominal injuries; however, duodenal injuries can lead to high morbidity [6]. Concomitant injuries to the pancreas and vascular structures are common, and risk of leak from any repair is high given the combination of gastric, pancreatic, and biliary secretions; therefore, these injuries remain challenging for the trauma surgeon [6,8]. While duodenal perforation can occur with blunt trauma, including seat belt injury, duodenal hematoma is more common in children. Duodenal perforation can be difficult to diagnose because it is a retroperitoneal organ and peritonitis is less likely to be evident at presentation.

●Large intestine – Colonic injuries most commonly occur in the transverse and sigmoid segments, which are not retroperitoneal [9]. Large cecal or right colon hematomas can occur due to direct blunt trauma. Rectal injuries can also occur due to high-pressure jet streams or penetration of foreign bodies. (See "Rectal foreign bodies".)

●Stomach – Gastric injuries are rare following blunt trauma, likely because the stomach is shielded by the rib cage. However, when perforations do occur, they are easy to diagnose because they will present with generalized peritonitis and a large amount of free air on imaging.

MECHANISM OF INJURY — Blunt hollow viscus injuries arise from sudden direct force applied to the abdomen. Common mechanisms include:

●Improper restraint with a lap seat belt in children younger than eight years of age or <57 inches (145 cm) tall during a motor vehicle collision (image 1) [5,10-12]

●Fall from a bicycle or scooter onto the handlebar (image 2) [13,14]

●Other direct blow to the abdomen (eg, sports injury, assault, or horse kick) [15]

These mechanisms are specific to children because their thinner abdominal wall and lack of peritoneal fat provides less protection to the viscera.

Rare injuries include unintentional intestinal prolapse and evisceration from unsafe pool drains or rectal perforation caused by high-pressure water streams from a jet ski [16,17].

Lap seat belt injury — Lap seat belt injury occurs when children are improperly restrained in a motor vehicle collision. The poor fit of a lap seat belt that is used without a properly fitted child safety seat in younger children permits the seat belt to ride up over the pelvis and compress the intra-abdominal contents against the spine during rapid deceleration. This injury pattern occurs most commonly in children between three to nine years of age [12].

The "seat belt sign" refers to linear abdominal ecchymoses (picture 1) across the abdomen, below the seat belt. They are strongly and independently associated with significant intra-abdominal injury, including hollow viscus injuries (image 1) [5,10,11]. For example, in a multicenter prospective study from the Pediatric Emergency Care Applied Research Network (PECARN) group that analyzed blunt abdominal trauma in over 3700 patients, seat belt sign was present in 16 percent of patients, and hollow viscus injuries were significantly more common in children with a seat belt sign who underwent definitive testing compared with those who did not have a seat belt sign (11 versus 1 percent) [5]. Furthermore, patients with a seat belt sign were more likely to undergo laparotomy than those without a seat belt sign (6 versus 1 percent). Of note, the 11 percent incidence of hollow viscus injury with seat belt sign in this study is lower than the 25 percent incidence reported in prior studies [10,11]. The seat belt sign as an indicator of intra-abdominal injury is discussed in more detail separately. (See "Pediatric blunt abdominal trauma: Initial evaluation and stabilization", section on 'Seat belt sign'.)

Handlebar injury — During a fall from a bicycle or scooter, the handlebar can strike the abdomen with significant force. Hollow viscus injuries resulting from this mechanism are well described [13,14]. Thus, any child with abdominal pain or abdominal wall bruising associated with a handlebar injury (picture 2) warrants careful evaluation (image 2). Because the initial fall may be viewed as trivial, the patient may occasionally present in a delayed fashion after the injury with anorexia and vomiting [18].

Direct blow — Direct blows such as from a horse kick, sports injury, or assault may also cause a hollow viscus injury [15].

Child abuse — The diagnosis of a hollow viscus injury in a child with a questionable or absent mechanism of injury is an important red flag for possible abuse, especially in a patient younger than five years of age [4,19,20]. Duodenal hematoma, duodenal perforation, and jejunal injuries are most commonly described. In a observational study of over 19,000 children with non-accidental trauma (child abuse) reported to the United States National Trauma Data Bank (NTDB), hollow viscus injuries accounted for 3 percent of all injuries and 28 percent of abdominal injuries [19]. Additionally, the presence of a hollow viscus injury in this population was the factor with the highest independent probability of death, probably due to the fact that the majority of these injuries had a delayed presentation for surgical care. In addition, evaluation and treatment of other abusive injuries and involvement of a multidisciplinary child abuse team, whenever available, are essential. (See "Physical child abuse: Recognition", section on 'Visceral injuries' and "Physical child abuse: Diagnostic evaluation and management".)

Pool drain evisceration — Rarely, intestinal prolapse, evisceration or amputation may result from a young child sitting directly on a pool drain [16]. This action forms a seal around the drain and centers the negative pressure at the anus. This injury has resulted in intestinal failure and subsequent death from complications of multivisceral transplantation. Modern pool or spa drains have design features, such as a suction cover, that prevent this injury, but older private pools can still pose this hazard.

Hydrostatic rectal injury — Rectal perforation can rarely occur from a high-pressure water stream from a jet ski directed into the anal canal [17].

STABILIZATION — Initial evaluation of pediatric trauma patients should follow the standard Advanced Trauma Life Support (ATLS) protocol, with life-threatening injuries that compromise airway, breathing, and circulation addressed first (table 1). Assessment for abdominal injury should take place as part of the secondary survey. (See "Trauma management: Approach to the unstable child", section on 'Abdomen'.)

EVALUATION

History — A focused history should identify the mechanism of injury, the presence of abdominal pain, vomiting, and any associated injuries found on the primary and secondary trauma surveys. (See "Trauma management: Approach to the unstable child".)

High-risk mechanisms for hollow viscus injury include any one of the following (see 'Mechanism of injury' above):

●Improper restraint with a lap seat belt during a high-speed motor vehicle collision

●Handlebar injury after falling from a bicycle

●Direct abdominal blow with significant force (eg, punch, kick, football tackle, fall from a height onto the abdomen)

In patients whose injuries are caused by child abuse, especially infants and children younger than five years of age, the history is typically implausible or absent. Vomiting, including bilious emesis, with an inability to tolerate oral intake is a frequent chief complaint that can arise from occult duodenal injury. If the abused child has a bowel perforation, fever may also be reported. (See "Physical child abuse: Recognition", section on 'Visceral injuries'.)

Physical examination — Patients with hollow viscus injury may have tachycardia, poor perfusion, and/or hypotension due to associated hemorrhage, sepsis, or both. However, signs of shock are often not present initially in these patients in the absence of significant bleeding from other injuries.

In patients with excessive vomiting and abdominal distention, a nasogastric (or, in patients with maxillofacial trauma, an orogastric) tube is warranted before abdominal examination or prior to transport to computed tomography (CT) to minimize the risk of aspiration.

Physical signs that should raise concern for hollow viscus injury or other intra-abdominal injuries include:

●Ecchymoses suggestive of a handlebar injury (picture 2) or other direct blow

●Seat belt sign (picture 1)

●Abdominal tenderness

●Peritoneal signs (eg, abdominal distension not relieved by gastric tube placement, abdominal rigidity, guarding or rebound on palpation, left shoulder pain on left upper quadrant palpation [Kehr sign], or absent bowel sounds)

●Upper abdominal mass (rare but suggestive of duodenal hematoma when present)

The abdominal examination may be unreliable in children with concurrent extra-abdominal injury (eg, head trauma, thoracic trauma, or extremity fracture) or impaired neurologic status (eg, traumatic brain injury or substance use). Clinicians should have a lower threshold for additional studies and observation in these patients.

Children with significant hollow viscus injuries may have limited findings other than persistent abdominal tenderness soon after injury. During observation, they may demonstrate tachycardia, fever, increasing signs of peritoneal irritation, vomiting, or a combination of these findings within 24 hours.

Laboratory studies — Laboratory studies are adjuncts to diagnosis but are not substitutes for clinical assessment and further imaging of children with suspected gastrointestinal trauma.

While there is no standardized "trauma panel," the following laboratory studies are warranted in children with blunt abdominal trauma and suspected intra-abdominal injury (see "Pediatric blunt abdominal trauma: Initial evaluation and stabilization", section on 'Laboratory evaluation'):

●Complete blood count

●Blood type and crossmatch

●Venous or arterial blood gas

●Serum transaminases (alanine aminotransferase [ALT] and aspartate aminotransferase [AST])

●Serum electrolytes, creatinine, blood urea nitrogen

●Blood glucose

●Amylase, lipase

●Prothrombin time (PT), partial thromboplastin time (PTT)

●Urinalysis

Imaging — Abdominal and pelvic CT with intravenous (IV) contrast is the preferred initial diagnostic imaging modality to evaluate for hollow viscus injury. Free intraperitoneal or retroperitoneal air (even a few bubbles) confirms the diagnosis of hollow viscus perforation (image 1 and image 2). However, the initial CT frequently may be normal or have minimal findings. (See "Pediatric blunt abdominal trauma: Initial evaluation and stabilization", section on 'Abdominal and pelvic CT'.)

Initial CT is typically diagnostic in patients with gastric perforations because pneumoperitoneum and peritonitis develop soon after injury. By contrast, findings of bowel perforation take more time to develop and are often subtle soon after injury because pneumoperitoneum or free fluid caused by leakage of bile or stool may not be apparent [6]. In addition, injuries of retroperitoneal structures such as the duodenum and posterior ascending and descending colon can be even more difficult to diagnose during initial CT evaluation because they do not cause peritonitis.

Suggestive signs of bowel injury on CT include bowel wall thickening, mesenteric abnormality, irregular contrast bowel enhancement, and free fluid without solid organ injury [21]; but these findings, in isolation, are not diagnostic.

Bedside focused assessment with sonography for trauma (FAST) has a limited role in patients with hollow viscus injury. Children with blunt abdominal trauma and intraperitoneal fluid on FAST who are too unstable to undergo CT of the abdomen typically warrant operative intervention in lieu of CT because the reason for instability is likely due to bleeding. Children with hollow viscus injury and sepsis who present many hours after injury may have free fluid, but since bleeding is unlikely, stabilization with fluid resuscitation and definitive imaging prior to operative repair is a safer approach.

The role of FAST for other intra-abdominal injuries is discussed separately. (See "Pediatric blunt abdominal trauma: Initial evaluation and stabilization", section on 'Ultrasonography'.)

DIAGNOSIS — During the initial evaluation, physical findings of pneumoperitoneum or peritonitis on physical examination or imaging (image 1 and image 2) establish the diagnosis of hollow viscus perforation. These patients warrant emergency surgery and operative repair. (See 'Pneumoperitoneum or peritonitis' below.)

The diagnosis of hollow viscus injury should also be suspected in children with the following clinical features soon after injury:

●History of high-risk mechanism of injury (eg, lap seat belt injury from a high-speed motor vehicle collision, handlebar injury after a fall from a bicycle, or high-force direct blow to the abdomen)

●Physical examination demonstrating any one of the following:

•Persistent abdominal tenderness

•Abdominal ecchymoses (picture 1 and picture 2)

•Peritoneal signs (eg, abdominal distension not relieved by gastric tube placement, abdominal rigidity, guarding or rebound on palpation, left shoulder pain on left upper quadrant palpation [Kehr sign], or absent bowel sounds)

•Upper abdominal mass (rare but suggestive of duodenal hematoma when present)

●Imaging suggestive but not diagnostic for hollow viscus injury (eg, computed tomography [CT] findings of bowel wall thickening or mesenteric abnormality such as mesenteric hematoma or stranding)

Patients with any of these suggestive findings for hollow viscus injury based upon initial evaluation warrant hospital admission to a pediatric trauma center and observation for signs of peritonitis or bowel hematoma. (See 'Suspected hollow viscus injury' below.)

Diagnostic peritoneal lavage has fallen out of favor due to its invasiveness, risk of causing injury, and lack of specificity compared with CT and laparoscopy. (See "Pediatric blunt abdominal trauma: Initial evaluation and stabilization", section on 'Peritoneal lavage'.)

DIFFERENTIAL DIAGNOSIS — Injury to the liver, spleen, or pancreas present with similar clinical features as hollow viscus injuries, including hemodynamic instability, abdominal pain, and tenderness. Hemorrhage from a solid organ injury can also cause peritoneal findings. (See "Liver, spleen, and pancreas injury in children with blunt abdominal trauma".)

Solid organ injuries following blunt abdominal trauma are typically detected by the initial computed tomography (CT) of the abdomen and pelvis with intravenous (IV) contrast. By contrast, hollow viscus injuries frequently produce subtle or no obvious findings on the initial CT. (See 'Imaging' above.)

Hollow viscus injuries may coexist with solid organ injuries to the liver, spleen, and/or pancreas [22]. Thus, patients with solid organ injury warrant careful monitoring for signs of hollow viscus injury while undergoing nonoperative management of their solid organ injury.

MANAGEMENT — Children with suspected hollow viscus injury require evaluation and continuing management by a trauma surgeon with pediatric expertise. In settings where pediatric surgical and intensive care are not available, these patients should undergo transfer for definitive care at a pediatric trauma center.

Pneumoperitoneum or peritonitis — Patients with evidence of perforation (ie, pneumoperitoneum and/or peritonitis) warrant timely operative repair. Important preoperative management includes intravenous (IV) antibiotics to cover bowel flora (eg, piperacillin with tazobactam or cefepime and metronidazole) and, for hemodynamically unstable patients, fluid resuscitation, which may also include blood transfusion. (See "Trauma management: Approach to the unstable child", section on 'Fluid resuscitation'.)

For stable patients with isolated hollow viscus injury, laparoscopy or traditional exploratory laparotomy may be used for the initial operative management of patients.

Exploratory laparoscopy is supported by a retrospective National Trauma Data Bank (NTDB) study demonstrating fewer complications, lower mortality, shorter hospitalizations, and no increase in missed traumatic injuries for patients undergoing exploratory laparoscopy and repair for intra-abdominal injuries compared with laparotomy [22]. However, patients undergoing laparoscopic repair had lower injury severity. If exploratory laparoscopy is used, any hollow viscus injuries that are seen can either be repaired laparoscopically, or the location and extent of the injury can be identified, which may limit the length of the open incision. With either the laparoscopic or open approach, a thorough abdominal evaluation should be performed.

The intraoperative management depends upon the type of injury, anatomic location, and severity:

●Lacerations of the stomach or small intestines – Small gastric or intestinal lacerations can be repaired primarily as long as the tissue appears well perfused. Larger injuries often require resection, which may be performed using a stapled wedge resection for gastric injury or a segmental intestinal resection [6]. Care must be taken to avoid narrowing of the lumen and to ensure that all devitalized tissue is resected.

Duodenal perforations are the most complex to manage because of the high risk of leakage caused by the high volume of gastric, pancreatic, and biliary fluid that passes through the duodenum daily. Small duodenal injuries may be managed with primary repair following debridement of devitalized tissue in a transverse fashion to avoid narrowing the duodenal lumen. It is vital that the duodenum is thoroughly mobilized (a full Kocher maneuver) in order to evaluate the posterior wall.

For duodenal injuries that disrupt more than 50 percent of the circumference (American Association for the Surgery of Trauma [AAST] grade III and higher [23]), options include:

•End-to-end duodenostomy

•Tension-free, Roux-en-Y duodenojejunostomy

•Billroth II (antrectomy and gastrojejunostomy)

If these repairs are tenuous, or the patient is at high risk for dehiscence, then they can be protected with a pyloric exclusion to avoid gastric fluid from bathing the fresh anastomosis [6]. A small observational study suggests that pyloric exclusion may not be necessary to assure good outcomes and may prolong hospitalization [24]. However, more evidence is needed to determine the optimal approach. For unstable patients, placement of a tube duodenostomy within the defect that is externalized through the skin until the patient is stable enough for formal repair provides a "damage control" option [23].

Combined duodenal-pancreatic head injuries (rare in children) may end up requiring a pancreatoduodenectomy (Whipple procedure). However, this procedure is not recommended until the patient is stable; damage control options should be considered until the patient is stable enough for formal reconstruction [23].

●"Bucket handle" mesenteric injuries – Mesenteric injuries that lead to a "bucket handle" segment of devascularization of the associated intestine also require intestinal resection. If these injuries are not addressed, then they can lead to bowel stricture, and children will present a few weeks after injury with a bowel obstruction [25].

●Injuries to the colon or rectum – Injuries to the colon or intraperitoneal rectum historically required diversion with a colostomy, but primary repair or segmental resection and anastomosis may be an option, even if there is stool contamination [6]. For example, in a retrospective review from the NTDB of over 500 pediatric patients who received colostomies for colorectal trauma, diversion colostomies were associated with similar complication incidence, but longer hospital stays, compared with children undergoing primary anastomosis [26]. Prospective studies confirming these findings are needed to clarify the best surgical approach.

Extraperitoneal rectal injuries generally require diversion with colostomy to permit natural healing; however, presacral drains and rectal washout are no longer recommended [27]. Pelvic abscess may develop with delayed presentation, which can generally be managed with percutaneous drainage.

Suspected hollow viscus injury — For stable patients with concern for bowel or mesenteric injury but equivocal findings, we suggest initial nonoperative management with close observation for the development of clinical signs of peritonitis rather than early surgical exploration [28,29]. Physical findings of peritonitis include tachycardia (often the first sign), fever, increased abdominal pain or peritoneal signs (eg, guarding, rebound, or rigid abdomen), nausea, and/or persistent vomiting.

Key interventions during observation include:

●No oral intake (keep patient NPO)

●After initial fluid resuscitation, provide maintenance IV fluid (eg, Lactated Ringer with dextrose) with adjustments made, as needed, based upon vital signs, urine output, and need to replace further losses (eg, ongoing vomiting)

●Serial abdominal exams every six hours by a surgeon or other clinician with trauma expertise

Gastric tube placement should be avoided in patients with suspected gastric or duodenal perforation to avoid further injury. Otherwise, individuals who are vomiting and have abdominal distensions may undergo nasogastric or, if oromaxillary injury is present, gastric tube placement and decompression.

Further care is determined by the patient's clinical course:

●Patient develops peritonitis – If the child develops peritonitis, then the surgeon should perform timely operative repair.

Antibiotics should only be administered once the diagnosis of hollow viscus injury is confirmed clinically or radiographically to avoid masking signs and symptoms of peritonitis and delaying surgical intervention.

Once a diagnosis of hollow viscus injury is made, the child should promptly receive parenteral antibiotics to cover bowel flora (gram-negative and anaerobic organisms). Potential antibiotic regimens include piperacillin with tazobactam or cefepime and metronidazole. IV fluid resuscitation should be initiated, as needed (see "Hypovolemic shock in children in resource-abundant settings: Initial evaluation and management"), and the patient should be taken to the operating room as soon as possible. (See 'Pneumoperitoneum or peritonitis' above.)

Awaiting clear manifestations of peritonitis may take up to 24 hours in stable patients with blunt intestinal injury. This delay in operation has raised concern for increasing the risk of morbidity and mortality from abdominal sepsis. This problem is highlighted in abused children with hollow viscus injuries, who always have a delayed presentation and have a 2.3 times increased risk of mortality compared with children that are not abused [19].

However, limited evidence and our experience suggest that observation versus early surgery in stable children with possible hollow viscus injury is safe. For example, in a retrospective, observational, multicenter study of over 200 United States children with blunt intestinal injury, all deaths occurred in children undergoing operation within 12 hours and were associated with high injury severity scores [29]. Early and late complications were similar regardless of the time to surgery. However, over 90 percent of patients underwent surgery within 24 hours. Thus, evidence is limited regarding clinical outcomes in stable children with blunt intestinal injury who undergo surgery beyond 24 hours.

In adults, the Bowel Injury Prediction Score (BIPS), which includes a new computed tomography (CT) grading scale for mesenteric injury, has been proposed to increase the sensitivity of CT findings and aid in earlier diagnosis of blunt bowel and mesenteric injury [30]. However, it requires further study, especially in pediatric patients. When adapted in a single-center retrospective study of patients with surgically proven bowel injury that included teenagers older than 14 years, the BIPS score only identified 56 percent of patients, and 9 percent of patients had completely normal CT at presentation. Additionally, free air, bowel wall thickening, hypoenhancement or discontinuity, or contrast extravasation were not commonly identified on initial CT [31].

●Persistent symptoms but no clear findings of perforation – When the patient persists with concerning physical findings, repeat CT imaging is warranted. If radiographic findings are suggestive but not diagnostic, then diagnostic laparoscopy is an option to clarify the injury and intervention:

•If a bowel perforation or bucket handle injury is identified on laparoscopy, then the operation may sometimes be completed using laparoscopic techniques, or, if laparotomy is necessary, then a smaller incision may be made to address the injury in an open fashion because the rest of the abdomen was already evaluated during laparoscopy. Smaller incisions generally lead to less pain and fewer associated complications. (See 'Pneumoperitoneum or peritonitis' above.)

•Patients with peritonitis caused by hemorrhage without perforation may not require open surgery or bowel resection if the bleeding is from the mesentery or a stable hematoma. Thus, laparoscopy avoids laparotomy for these patients. (See 'Duodenal hematoma' below and 'Extraduodenal intestinal hematomas' below.)

●Patient improves – If no further signs or symptoms of hollow viscus injury develop by 12 hours, then oral intake can be started, and the patient can be discharged by 24 hours if they continue to tolerate advancing oral intake and remain stable with improvement or resolution of their signs and symptoms.

Observation of patients with equivocal findings after blunt abdominal trauma avoids unnecessary operation. In particular, early surgical intervention is not indicated in children with blunt abdominal trauma and isolated free intraperitoneal fluid on CT but no peritonitis on initial physical examination because the likelihood of hollow viscus injury appears to be low. For example, in a case series of 94 pediatric patients who had isolated free fluid on initial CT, only two (2.1 percent) had hollow viscus injuries, both of whom developed peritonitis after admission [28].

Duodenal hematoma — In patients with duodenal hematoma, nonoperative treatment is generally sufficient as long as there is no associated perforation. These patients initially have gastric outlet obstruction, which can be managed with nasogastric decompression and parenteral nutrition or feeding via a nasojejunal tube. The hematoma may take days to weeks to resolve [32]; however, given the high morbidity associated with duodenal surgery, this is an acceptable recovery time.

Extraduodenal intestinal hematomas — Intestinal hematomas in sites other than the duodenum are rare in children with blunt abdominal trauma. With the exception of intramural cecal hematomas, they are managed similar to duodenal hematomas. However, because the thin wall of the cecum is associated with pressure necrosis and perforation, early surgical resection of intramural cecal hematomas may be warranted [33]. Otherwise, our experience suggests that colonic necrosis and perforation may occur, even in asymptomatic patients.

Suspected child abuse — In addition to management as described above, children with hollow viscus injuries who have an implausible or absent history of trauma or have other signs suggestive of child abuse (table 2) warrant additional evaluation in consultation with a multidisciplinary child abuse team. In many regions, mandatory reporting to the appropriate government agency responsible for further legal investigation is also required. (See "Physical child abuse: Recognition" and "Child abuse: Social and medicolegal issues".)

COMPLICATIONS — Retrospective observational studies suggest that the risk of complications after surgery for hollow viscus injury ranges from 3 to 10 percent and typically consists of wound infection or abscess [3,22]. Mortality is described in up to 11 percent of patients, although it is often caused by concomitant injuries such as traumatic brain injury [34]. Child abuse is associated with an increased risk of death due to hollow viscus injury; this finding is likely explained by delayed presentation, which results in a higher likelihood of microbial contamination of the abdomen with postoperative sepsis [19].

Abscesses can generally be managed with percutaneous drainage and antibiotics. However, if there is a clear anastomotic breakdown or the patient develops sepsis, then reoperation with thorough abdominal washout and proximal diversion of the stool stream is of utmost importance for source control. Wound infections occur due to bacterial contamination during the operation, ongoing gastrointestinal leakage, or communication with intra-abdominal abscess and rarely result in a fistula. These are managed by partial or complete skin opening to permit passive drainage.

Finally, any abdominal operation carries a lifelong risk factor for future adhesive small bowel obstruction, although the risk appears to be low (2 to 4 percent) [22,34].

FOLLOW-UP — Because delayed complications are rare, children with hollow viscus injury who recover well after surgery and demonstrate full return of bowel function and clearance of infection typically need one or two follow-up visits with the surgeon.

If children are discharged after observation without evidence of hollow viscus injury, a single follow-up visit at two weeks, either by the pediatrician or trauma surgeon, is generally adequate to ensure that there is no delayed complication of intestinal obstruction from stricture due to either mesenteric bucket handle injury or partial bowel ischemia.

SUMMARY AND RECOMMENDATIONS

●Initial evaluation of pediatric trauma patients with possible hollow viscus injury should follow the standard Advanced Trauma Life Support (ATLS) protocol, which prioritizes treatment of immediate life-threatening injuries that compromise airway, breathing, and circulation (table 1). Assessment for hollow viscus injury should take place as part of the secondary survey. (See 'Stabilization' above.)

●A focused history should identify the mechanism of injury, the presence of abdominal pain, vomiting, and any associated injuries found on the primary and secondary trauma surveys. High-risk mechanisms for hollow viscus injury include any one of the following (see 'History' above):

•Lap seat belt injury (picture 1) occurs in an improperly restrained child who is injured in a motor vehicle collision

•Handlebar injury after a fall from a bicycle or scooter (picture 2)

•Direct blow to the abdomen (eg, sports injury, assault, or horse kick)

●In patients whose injuries are caused by child abuse, especially infants and children younger than five years of age, the history is typically implausible or absent. Vomiting, including bilious emesis, with an inability to tolerate oral intake is a frequent chief complaint that can arise from occult duodenal injury. If the abused child has a bowel perforation, fever may also be reported. (See 'History' above.)

●Physical signs that should raise concern for hollow viscus injury or other intra-abdominal injuries include (see 'Physical examination' above):

•Ecchymoses suggestive of a handlebar injury or other direct blow

•Seat belt sign

•Abdominal tenderness

•Peritoneal signs (eg, abdominal distension not relieved by gastric tube placement, abdominal rigidity, guarding or rebound on palpation, left shoulder pain on left upper quadrant palpation [Kehr sign], or absent bowel sounds)

•Upper abdominal mass (rare, but suggestive of duodenal hematoma when present)

The abdominal examination may be unreliable in children with concurrent extraabdominal injury (eg, head trauma, thoracic trauma, or extremity fracture) or impaired neurologic status (eg, traumatic brain injury or substance use). Clinicians should have a lower threshold for additional studies and observation in these patients.

●Suggested laboratory studies are provided above. Laboratory studies are adjuncts to diagnosis but are not substitutes for clinical assessment and further imaging of children with suspected gastrointestinal trauma. (See 'Laboratory studies' above.)

●Abdominal and pelvic computed tomography (CT) with intravenous (IV) contrast is the preferred initial diagnostic imaging modality to detect hollow viscus injury and other intra-abdominal injury in hemodynamically stable children who have sustained significant blunt abdominal trauma. Free intraperitoneal or retroperitoneal air (even a few bubbles) (image 1 and image 2) confirms the diagnosis of hollow viscus perforation. However, CT frequently may be normal or have minimal findings during the initial evaluation of these patients. (See 'Imaging' above.)

●Physical findings of pneumoperitoneum or peritonitis on physical examination or imaging establishes the diagnosis of hollow viscus perforation. These patients warrant emergency surgery and operative repair by a surgeon with pediatric trauma expertise. The intraoperative management depends upon the type of injury, anatomic location, and severity. (See 'Diagnosis' above.)

●Children with significant hollow viscus injuries may have limited findings other than persistent abdominal tenderness soon after injury. Patients with concerning clinical features associated with hollow viscus injury or CT findings suggestive but not diagnostic for hollow viscus injury warrant hospital admission to a pediatric trauma service and observation for signs of peritonitis or bowel hematoma. (See 'Diagnosis' above.)

●For stable patients with potential for bowel or mesenteric injury but equivocal findings, we suggest initial nonoperative management with close observation for clinical signs of peritonitis by a pediatric trauma team. Key interventions during observation include (see 'Suspected hollow viscus injury' above):

•No oral intake (keep patient NPO)

•After initial fluid resuscitation, maintenance IV fluid (eg, Lactated Ringer with dextrose) with adjustments made, as needed, based upon vital signs, urine output, and need to replace further losses (eg, ongoing vomiting)

•Serial abdominal exams every six hours by a pediatric surgeon or trained trauma professional with pediatric expertise

Further care is determined by the patient's clinical course. Antibiotics should only be administered once the diagnosis of hollow viscus injury is confirmed clinically or radiographically to avoid masking signs and symptoms of peritonitis and delaying surgical intervention.

●In addition to management as described above, children with hollow viscus injuries who have an implausible or absent history of trauma or have other signs suggestive of child abuse (table 2) warrant additional evaluation in consultation with a multidisciplinary child abuse team. In many regions, mandatory reporting to the appropriate government agency responsible for further legal investigation is also required. (See "Physical child abuse: Recognition" and "Child abuse: Social and medicolegal issues".)

ACKNOWLEDGMENT — The UpToDate editorial staff acknowledges Haley Guzzo, MD and William Middlesworth, MD, FAAP, FACS, who contributed to an earlier version of this topic review.