Rectal Trauma

Etiology

The majority of rectal injuries are secondary to penetrating trauma, excluding iatrogenic, sex-related, and foreign body injuries. Gunshot wounds compose 85 to 90% and stab wounds approximately 5%. Approximately 5 to 10% are secondary to blunt trauma of which 1 to 2% are associated with pelvic fractures, most specifically anterior-posterior compression.[4][5][6][7]

Epidemiology

The incidence of rectal trauma in civilian trauma centers is 1 to 3%, and in recent military conflict, up to 5%. The military rectal wounds involve much higher velocity weaponry, blast injuries, fragmentations, and burns.[8]

Pathophysiology

The rectum is approximately 15cm long. It has an intraperitoneal portion, which includes the upper two-thirds anteriorly and the upper one third laterally. The lower third of the rectum is extraperitoneal. The blood supply is from the superior hemorrhoidal branches from the inferior mesenteric artery, the middle hemorrhoidal branch of the internal iliac artery, and the inferior hemorrhoidal branch of the internal pudendal arteries.

Decision making for management of rectal injuries has as its basis intraperitoneal and extra-peritoneal zones and the Rectum Injury Scale of the American Association for the Surgery of Trauma (image attached below).[9]

History and Physical

In the trauma patient, a systemic approach of the entire patient must be conducted, without exception, as outlined by the Advanced Trauma Life Support (ATLS) Program. An initial assessment of the patient is of utmost importance before focusing on the specific anatomic regions of obvious traumatic injury. The concept of this initial assessment, as outlined by the ATLS, includes a systematic evaluation including a primary survey, resuscitation, and detailed secondary survey with continuous re-evaluation through all steps.

The primary survey is designed to identify immediate life-threatening injuries quickly. Therefore, the universal approach has been established by the ATLS to follow the following in specific order: airway maintenance, breathing (ventilation), circulation (including hemorrhage control), disability (neurologic status), and exposure. Airway assessment and management have the highest priority of any injured patient irrespective of mechanism or wound location.[10] This cannot be overemphasized, to first secure or ensure a patent airway, before proceeding methodically, in appropriate order through the ATLS protocol.

During the primary survey, complete exposure of the patient is essential, as is to roll the patient potentially to both sides, as to not overlook penetrating injuries that may not be easily identifiable when lying in a supine position. The assessment includes an examination of the perineum, buttocks, and lower gluteal, anal, or groin folds (as is vital to examine the patients back, flanks, and axilla).

Recognition of rectal injuries requires a high level of suspicion in those evaluating any patient with a penetrating wound. This suspicion should increase with any identification of penetrating wounds to the lower abdomen, pelvis, perineum, buttocks, or thighs. Penetrating wounds should be counted and marked (one approach is a simple paper clip gets taped adjacent to the penetration site) to help physicians hypothesize missile projection. If the count is an odd number of penetrating wounds, the physician should have heightened suspicion that a foreign body may remain in the victim.

As with all penetrating wounds via knife, spear, or other large objects, these should not get removed until the patient is in a controlled environment, i.e., the operating room, no matter the location of the foreign body.

In all patients who are hemodynamically stable, alert, and oriented, obtaining a detailed history of the events surrounding their injury is essential. Questions pertinent to ask include proximity of projectile when fired, and caliber of the weapon if known. With all patients, it is crucial to attempt to obtain previous past medical, past surgical, and social histories as well as current patient medications and known drug allergies.

Evaluation

In the diagnostic assessment of a trauma patient, bedside ultrasonography in the form of the focused assessment with sonography for trauma (FAST) examination is considered standard of care. This diagnostic modality allows the operator to perform evaluations simultaneously during the primary of the initial assessment, as outlined above. Of the four views, the suprapubic location with visualization of the pelvic cul de sac requires inspection with a concern of penetrating rectal trauma. The presence of fluid in this window may indicate intra-abdominal hemorrhage, hollow viscus injury, hemoperitoneum, or ascites. A threshold of at least 200mL of fluid is necessary for the detection of fluid within the intra-abdominal cavity. Most recently, a FAST exam is noted to have a sensitivity of 69.8% and a specificity of 92.1%.[11] Positive findings in a stable patient can be evaluated further with CT. In contrast, positive findings in an unstable patient necessitate the surgeon to take the patient to the operating room for emergent abdominal exploration.

Prio practice was that all patients where there was a concern of penetrating rectal injury should undergo a digital rectal exam during the secondary trauma survey; this, however, has raised controversy and recently been called into question. Digital rectal examination is, however, not supported due to low sensitivity, approximately 51% of this test being inadequate to effectively rule out injury, coupled with significant risk for enlargening rectal perforation with a blind examination.[12][13][14][15] The physician, however, may attempt to directly visualize rectal injury with a higher yield modality, such as intraoperative examination with proctosigmoidoscopy. A senior-level physician who is familiar with proctosigmoidoscopy should perform this exam. If the location of the injury is not identifiable, blood seen on rigid proctosigmoidoscopy has been determined to have a sensitivity as high as 90% for the diagnosis of rectal injury.[16]

Computer tomography (CT) with IV contrast is the most useful adjunct for evaluation in the stable trauma patient to help identify missile trajectory, in addition to evaluation and/or determination of other concomitant injuries. If encountering hematuria during Foley catheter insertion, CT cystography may as well be useful to rule out associated bladder injury.[17][18]

Treatment / Management

The evidence-based management of rectal trauma is formulated based on the patient’s physiology and anatomy. Physiologically the patient is either hemodynamically stable or unstable with massive blood loss, acidosis, hypothermia, and coagulopathy. These patients would go straight to the operating room and have a damage control operation performed. This scenario is not uncommon for rectal trauma since the etiology is 85% gunshot wounds and blunt injuries are usually secondary to open-book pelvic fractures.

For the hemodynamically stable patient, the rectal injury is repaired based on the anatomy of the wound.[19] The rectum is partially intraperitoneal (anterior and lateral surfaces of the upper two-thirds, and partly extraperitoneal (posterior surface, and circumferential lower one-third). The management of intra-peritoneal wounds is the same as colon injuries. Primary repair with or without proximal diversion. The patient should also receive broad-spectrum antibiotics covering gram-negative and anaerobes for 24 hours. If the injury is nondestructive (less than 50% of the circumference of the intraperitoneal rectum), it can undergo repair. If the wound is destructive (greater than 50% circumferential involvement), the rectum requires resection to viable, healthy tissue and re-anastomosed.

Over the last several decades, there have been multiple studies showing that fecal diversion is not necessary, except in the setting of various transfusion requirements or hypotension. In 1979 Stone and Fabian performed a randomized prospective trial comparing primary repair of colon injuries versus colostomy creation and found equivalent infection (48% vs. 57% p>0.05) and mortality rates (1.5% vs. 1.4% p>50). This historical study revolutionized the management of colorectal trauma. In 2001, the American Association for the Surgery of Trauma conducted a prospective multicenter study on penetrating colon injuries, comparing diversion or primary repair. This study demonstrated lower mortality in the primary repair arm (0% vs. 1.3%).[9] A 2009 Cochrane review examined six randomized trials on colon injuries comparing primary repair versus fecal diversion from 1975 to 2002. [20] This also revealed a significantly lower rate of wound complication and infection with primary repair.(B2)

When considering diversion, one must take into account all of the complications of ostomies. There is a 35 to 55% complication incidence from forming an ostomy itself. The readmission rate is as high as 17% secondary to multiple potential complications, including parastomal hernias, stenosis, retraction, and metabolic imbalance.[21][22][23][24][25] With the reversal of the ostomy, there is a 5 to 25% complication rate, with a local wound infection rate of 3 to 20%.[21][23](A1)

In 2006, Gonzalez did a trial of 14 patients with nondestructive rectal trauma without fecal diversion and had no complications or mortality.[26] If one compares nondestructive rectal injuries in the non-trauma world, such as draining pelvic abscess of the rectum, excising rectal tumor trans-anally, or draining supra levator abscess via the rectum, none of these procedures require a fecal diversion.[27][28](B2)

For destructive extraperitoneal rectal trauma (greater than 50% circumferential involvement), associated pelvic fractures, or concomitant vascular injuries that can compromise the blood supply to the rectum causing anastomotic failure; fecal diversion would be a safe alternative. With regards to presacral drainage and distal washout, these procedures were established during the Vietnam Conflict and published in 1971 by Lavenson and Cohen. Over the past several decades, there have been numerous studies demonstrating no benefit in presacral drainage or distal rectal washout. For extraperitoneal rectal injuries, there is controversy over fecal diversion, presacral drainage, and distal rectal washout. The Eastern Association of the Surgery of Trauma (EAST) recently published guidelines on fecal diversion for extraperitoneal rectal trauma despite finding the quality of evidence to be weak, and conditionally recommended proximal diversion.[20] The Eastern Association of the Surgery of Trauma practice management guidelines on nondestructive penetrating extraperitoneal rectal injuries also conditionally recommended not performing rectal washout or pre-sacral drainage.[20]

The exception to this is wartime related injuries, where there is severe presacral destruction with large soft tissue injury or those associated with pelvic fractures. The patient with severe presacral destruction and large soft tissue injuries associated with pelvic fractures are much more commonly seen in war-related injuries.[29] It is in these patients where proximal diversion is indicated, with the use of pre-sacral drainage not clearly defined, and overall not well supported.

Blunt trauma accounts for 1 to 2% of rectal trauma and is usually secondary to an anterior-posterior compression mechanism causing an open book pelvic fracture.[6][7] These injuries should always have fecal diversion. (B2)

Concomitant bladder injury with rectal trauma does not increase the rate of abdominal complication nor mortality. Fecal diversion does not change the outcome of concomitant traumatic bladder injuries.[30]

Differential Diagnosis

Suspicion for rectal injury should increase with any identification of penetrating wound to the lower abdomen, pelvis, perineum, buttocks, or thighs. With the identification of trauma to this region, the differential diagnosis must include intra-peritoneal vs. extraperitoneal rectal injury, vascular injury, bladder injury. Nearly any major vasculature or viscera may be injured and subsequently must be excluded with the identification of a penetrating injury.

Prognosis

The overall prognosis for patients who sustain rectal trauma is again multifactorial, including but not limited to patient’s age, comorbidities, hemodynamics, concomitant injuries, and, as discussed, the location of injury (intraperitoneal compared to extraperitoneal). Despite advances in trauma guidelines, mortality rates en total remain between 3 and 10% with additional morbidity of 18 to 21%.[31]

Brown et al. performed a retrospective review from 2004 to 2015, of all patients sustaining a traumatic rectal injury at 22 participating level 1 trauma centers. They demonstrated patients with intraperitoneal rectal injuries that underwent proximal diversion sustained more abdominal complications thereafter than those that did not (22% vs. 10% p=0.003). Further independent risk factors for intra-abdominal complications in patients with intraperitoneal injury included a high-grade injury (defined as AAST grade greater than II) or if the mechanism of injury was of penetrating in nature. Regardless of proximal diversion, there was no difference in overall mortality (3% vs. 2% p=0.66), excluding patients that died within 48 hours of hospital arrival.[32]

Prognosis is similar concerning extraperitoneal injury. The same study showed no difference in mortality in the extraperitoneal rectal injury population, with proximal diversion, found to be (2% vs. 1% p=0.55), again excluding those that died within 48 hours of arrival. After multivariate analysis, independent risk factors for complications with extraperitoneal injuries were those that received distal rectal washout (OR 3.4 p=0.008) and presacral drain placement (OR 2.6 p=0.02).[32]

Although only selectively indicated for destructive extraperitoneal rectal injuries, proximal diversion and creation of an ostomy are important to note for prognosis, as this holds 25 to 55% complications incidence in and of itself.[21][22][23]

Complications

In most studies related to bowel injury, similar factors predispose to the relative risk for infectious morbidity and primary repair or anastomotic failure. These relative risks include fecal contamination, extensive blood loss, and hemodynamic instability or shock state. Further severe concern complications from direct rectal injury include wound infection, abdominal and or pelvic/retroperitoneal abscess, fistulous tract formation, fascial dehiscence, bacteremia, and necrotizing fasciitis.[19] Non-life-threatening conditions with lifestyle implications include not only possible ostomy maintenance but as well as fecal incontinence.

Despite increasing literature against and need to increase selectivity, proximal diversion, and ostomy creation in multi-institute studies examining rectal trauma are as high as 76%. Ostomy complications include parastomal hernias, stenosis, retraction, and metabolic imbalance. With the reversal of an ostomy, there is a risk for local wound infections between 3 to 20%.[21][22][23]