An unusual stab wound to the buttock.

Stab wounds to the buttock are uncommon injuries that are rarely seen in surgical civilian practice. Although, the wound appears trivial, it may cause major life-threatening visceral and vascular injuries. Failure to detect these injuries may lead to serious morbidity and mortality. Herein, we report a patient with a single gluteal stab wound, which was initially sutured and treated conservatively. Two days later, patient developed fever, lower abdominal pain and tenderness with leakage of fecal material from the wound. Exploratory laparotomy revealed an extraperitoneal rectal perforation for which a Hartmann's procedure was performed. Computed tomography scanning is recommended as a diagnostic tool for stable patients having buttock stab wounds. Diverging colostomy is the standard surgical procedure for extraperitonal rectal injuries that cannot be properly visualized and repaired during a laparotomy. More evidence is needed to assess the fecal non-diversion approach in the treatment of these patients.

INTRODUCTION

Stab wounds to the buttock are uncommon injuries that are rarely seen in the surgical civilian practice.[1] The wounds may appear trivial. However, major life-threatening visceral and vascular injuries may occur in about one quarter of these injuries.[2] The management of stab wounds of the gluteal region is challenging. There are no standards of care agreed on for the management of these injuries. The treatment of patients varies according to different trauma centers. Organ injuries related to these wounds may manifest slowly and failure to detect them may lead to death.[3]

Herein, we report a patient who sustained a single gluteal stab wound that was associated with rectal perforation. This case demonstrates the importance of clinical suspicion for early diagnosis of organ injuries caused by penetrating buttock stab wounds.

CASE REPORT

A 47-year-old diabetic man had a stab wound to his right buttock inflicted by his roommate using a kitchen knife. On examination, his pulse was 75 beats/min and his blood pressure (BP) was 100/50 mmHg. The abdomen was soft and not tender. A single wound was seen on the medial side of the right gluteal area superior to the intertrochanteric plane [Figure 1]. No neurological deficits were detected. Arterial pulses of the lower limbs were well-felt. The wound was sutured in the Emergency Department and patient was scheduled for discharge. Patient felt dizzy, complained of fresh bleeding per rectum and fainted before being sent home. At this stage, his pulse rate was 105 beats/min and his BP had dropped to 65/40 mmHg. Patient was resuscitated with crystalloids and he became hemodynamically stable. Rigid sigmoidoscopic examination was performed under general anesthesia and showed blood clots in the rectum with no active bleeding. No obvious injury to the rectal wall was seen despite the injection of methylene blue through the gluteal wound. Patient was admitted to the surgical ward for close observation. He was kept fasting, had intravenous fluids and antibiotics were administered. Two days later, patient complained of lower abdominal pain. Fecal matter passed through the gluteal wound. Patient had a temperature of 38°C. There was tenderness and guarding in the lower abdomen. Abdominal computed tomography (CT) scan with oral, rectal and intravenous contrast was performed. It showed contrast leakage from the posterior wall of the rectum, intraperitoneal free air and air in the mesentery around the rectum [Figures 2 and 3]. Exploratory laparotomy was performed. No intraperitoneal fecal soiling was seen. Nevertheless, there was a significant amount of air in the retroperitoneal space and in the bowel mesentery [Figure 4]. The rectum was mobilized, but the extraperitoneal perforation could not be seen. Hartmann's procedure was performed. Gluteal wound exploration revealed a deep laceration lateral to the edge of the sacrum. Debridement of the necrotic tissue was performed. Post-operatively, patient had slow recovery because of intestinal ileus. The colostomy started to function on the fourth post-operative day. Patient recovered completely at day 10 and was scheduled for reversal of the Hartmann's procedure 12 weeks after surgery. He decided to travel overseas to his home country to continue his treatment.

Figure 1

A diagram demonstrating the site of a single wound on the medial side of right buttock superior to the intretrochantric plane (line)

Figure 2

Abdominal computed tomography scan showing leakage of rectal contrast and air (arrow) from the posterior wall of rectum

Figure 3

Abdominal computed tomography scan showing air in the mesentery (arrow) and around the intestine

Figure 4

A significant amount of air is seen in the mesentery (arrow)

DISCUSSION

The thick fat that covers the gluteal muscle, sacrum and iliac bones gives a false assurance that stab wounds to the buttock do not cause serious injuries.[2]

Actually, there is a higher mortality from gluteal stab wounds compared with gluteal gunshot wounds.[4] This may be related to the delayed diagnosis of serious injuries caused by the false sense of security of what appears to be a simple wound.[2] Penetrating wounds to the buttock can cause serious vascular injuries (gluteal vessels, iliac vessels), nerve damage (the sciatic nerve, gluteal nerve) or pelvic and abdominal visceral injuries, depending on the direction and depth of the wound.[56789]

Gluteal penetrating wounds that are located superior to the intretrochanteric plane (as in our patient) can be associated with serious injuries.[2] If the gluteal wound has penetrated through the deep fascia, then the patient should be admitted for close and repeated clinical evaluation.[289]

Gunshot penetrating rectal injuries can be destructive, involving more than one quarter of the rectal circumference. Non-destructive wounds involving less than one quarter of the rectal circumference are usually caused by stab wounds. Our patient had a penetrating extraperitoneal non-destructive rectal injury. Gunshot and stab wounds of the buttock are two separate clinical entities and require different management approaches.[4] Management of penetrating rectal injury in civilian practice is rare. Most experience in these injuries is gained from managing wartime penetrating destructive rectal injuries.[9] Management includes performing a diverting colostomy, rectal injury repair (when feasible) and presacral drainage.

The management of buttock stab wounds depends on the site and direction of the wound and the hemodynamic status of patient.[146] If patient is in shock and the wound is bleeding externally, then the wound should be packed[6] and focused assessment sonography for trauma (FAST) should be carried out. If FAST is positive, then the patient needs a laparotomy.[4] If FAST is negative then the patient needs an angioembolization.[4]

Rectal examination, urine analysis, proctoscopy and sigmoidoscopy are useful diagnostic methods, especially when there is bleeding per rectum.[68] The rectal wall injury in our patient was missed by the rigid sigmoidoscopy. Clearly, air leaked through the perforation during this procedure and a significant amount of air was trapped in the retroperitoneal space and bowel mesentery. No intraperitoneal bowel perforation was detected during the laparotomy. Air leakage through the parietal peritoneum may have been the cause of intraperitoneal free air, which was detected by abdominal CT scan.[10]

The cornerstone of early diagnostic management for stable patients having buttock stab wounds has become CT scanning.[4] If patient is hemodynamically stable, then the wound should be explored in the Emergency Room and if the muscle fascia is violated then patient should have CT scan of the abdomen and pelvis.[1] If CT scan is negative, then patient should be admitted for observation[1] and if it shows free intraperitoneal air, then patient needs a laparotomy. If there is an arterial blush then angioembolization is indictaed.[14] If CT scan shows free intraperitoneal fluid then urethrocystography is indicated to rule out urinary bladder injury. Diagnostic peritoneal lavage will be useful in this case.[9] Laparatomy will be indicated if the hemodynamic status of patient deteriorates or patient develops peritonitis.[7] If CT scan shows an extraperitoneal rectal injury without a major intra-abdominal vascular or visceral injury in a hemodynamically stable patient, then conservative management with active close clinical observation can be adopted.[11]

Furthermore, presacral drainage may not be indicated for non-destructive penetrating extraperitoneal rectal injury in civilian practice.[12] We have used complete diverging colostomy in our patient because he was septic, diabetic and had an infected gluteal wound and a delayed diagnosis.

CONCLUSIONS

Stab wound of the buttock must be considered as a potentially serious injury. CT scanning is recommended as a diagnostic tool for stable patients having buttock stab wounds. Diverging colostomy is the standard surgical procedure for extraperitonal rectal injuries that cannot be properly visualized and repaired during a laparotomy. More evidence is needed to assess the fecal non-diversion approach in the treatment of these patients.