GUNSHOT WOUNDS OF THE ABDOMEN
 

Introduction:

GSWA continue to occur with increasing frequency in our country especially during the escalation of the Israeli – Palestinian conflict.

In wars the percentage of casualties with abdominal wounds on battlefields is near 20%, roughly half of these casualties (10%) are fatally wounded and die almost immediately from bleeding (1). However, the developments of efficient ambulance services, blood banks and regional trauma centers have contributed to the reduction of the mortality of injured patients (2). Also, the experience of our surgeons and all the medical and paramedical staffs, which developed during the Intifada (1987-1994), had positive impact in their performance in dealing with the injured patients.

The aim of this study is to declare our experience and to identify the important factors that influence the mortality and morbidity in patients with abdominal gunshot wounds.

 Patient and Methods:

We reviewed the records of 264 patients admitted to Shifa Hospital due to GSWA, during the period from September 2000 to April 2003. Of the 264 patients reviewed, 230 patients were explored   while the remaining 34 patients were observed and discharged without operations and hence were excluded from the study.

All patients were males with median age 20.4 years, ranged between 10 and 70 years. The surface anatomical definition of the abdomen was from the

 nipple line to the pubis anteriorly and from a line joining the inferior angles of the scapulae to the lower buttock crease, posteriorly (3). Patients with GSWA were classified into three groups; those unstable and or with evisceration were sent immediately to the operation room. The stable patients were prepared in the waiting area or the surgical department for surgery. The third group included those patients with equivocal signs and they were admitted to the department for more investigations and evaluation. Routine blood investigations e.g. complete blood picture and cross matching   performed for all patients. Plain x-rays for skull, chest, abdomen and extremities   done according to the needs. Ultrasonography performed to the stable patients with equivocal signs to see blood or fluid collection in the peritoneal cavity.

All patients with penetrating GSWA and positive abdominal signs underwent exploratory laparotomy, usually through a midline incision. Patients in whom the missile tract was tangential in the abdominal wall, appearing superficial to the peritoneum, were observed in the surgical department for 24 to 72 hours to exclude visceral injuries. When the depth of injury was in doubt or when equivocal abdominal signs occurred C-T scan of the abdomen was performed. Laparotomy was performed in patients that developed acute abdomen during observation; otherwise they were discharged home after few days

The approach to the gunshot wounds of the lower thorax was similar to that just outlined for abdominal gunshot wounds.

The realization that nearly half of gun shot wounds in the region are associated with significant intra-abdominal injury has led to a more aggressive search for visceral injury (4).

Peri-operative antibiotics given to all patients with penetrating abdominal wounds. Intravenous    ceftriaxone, or cefazolin and metronidazole were commonly used.

Splenorraphy rather than splenectomy was performed when the condition of the patient and the severity of the injury allowed. In this study 25% of splenic injuries resulting from gunshot wounds were repaired.

Hepatic injuries were managed by different techniques according to the severity of injury. The superficial wounds or the inlet and exit tract without any bleeding were left alone. In deep hepatic wounds resectional debridement or hepatotomy with selective vascular ligation were performed in preference to deep horizontal mattress sutures. Perihepatic packing to stop the bleeding on the basis of damage control surgery was used in 5% of patients with hepatic injuries during this study.

Pancreatic injuries not involving the major duct were treated by open Penrose drainage for 7-10 days. While moderate and severe injuries were treated with pyloric exclusion and antecolic gastro-jejunostomy.

Intraabdominal vascular injuries were treated with lateral arteriorraphy or venorraphy, whenever possible. When more extensive injuries were present, an end to end anastomosis   or insertion of a graft was performed. 

Wounds of gastrointestinal tract were usually closed in two layers using 3-0 vicryl sutures.

Colonic injuries treated with primary repair in 72% of cases, whereas colostomy was performed in another 28%.

Before closure, irrigation of the abdomen with saline was performed until the effluent was clear.

In patients with diffuse bleeding from the retroperitoneal space or pelvis an intraabdominal packs were left in the abdomen to control the bleeding and the patients sent to the intensive care unit for stabilization; usually for 24 to 72 hours then the packs removed in the operation room.

Intraabdominal drainage done either with Penrose drains or closed system tube drains.

Closure of the abdominal wall done either with mass suturing or in layers.

The Penetrating Abdominal Trauma Index (PATI) score for each patient was calculated as described by Moore et al (5). The trauma score was calculated for each organ injured by multiplying assigned risk factor (1-5) by the severity of each injury estimate (1-5), the sum of the individual organ injury score comprise the final PATI.

In the post operative period the diagnosis of a wound infection was confirmed by the presence of pathogenic organisms in exudates obtained from the wound (6).Intra abdominal abscess was defined as the presence of localized pus within the abdomen diagnosed by ultrasound or C-T scan.

Thoracic injuries due to penetration of chest resulted in haemopneumothorax were treated with local wound excision and chest drainage. Thoracotomy was done when the haemothorax was massive and more than 1500 ml of blood drained immediately after chest tube insertion or when the chest tube drained more than 200 ml blood per hour.

Data reviewed in this study were taken from the patient’s charts and or by personal contact.

Data were entered and analyzed on a personal computer using Epi Info version 6.02, (centers for Disease Control, Atlanta, GA).

Results:

 All the patients were males, their age ranged between 10 and 70 years with    mean age 20.4 years. High velocity bullets were the most common cause of injury while shrapnel from shell or rocket fragments were less common. Abdominal explorations were done in   230 patients. In 15 patients (6.5%) no intra abdominal injuries was found; while in the other 215 patients (93.5 %)  the commonly injured organs were the small intestine112 (48.7%),  colon 73 (31.7%), stomach 44 (19.1%) Table1. A total of 34 patients were discharged without operations and so were not included in the statistics.

Retroperitoneal haematoma (75, 32.6%),

Appendix 2, gallbladder 2

Table 1; Distribution of the injured organs

Among the extra abdominal injuries that occurred in 76 patients, the lungs were the most frequently injured organ; Table 2.

Table 2; Distribution of the extra abdominal injuries

 Eighty six complications related directly to GSWA   occurred in 78 (33.9%) patients. The most common complication encountered was wound infection which occurred in 39(17.0%) of all patients; table 3.

Table 3; Post operative complications

The number of organs injured versus mortality rate is depicted in table 4

Table 4; Number of injured organs versus mortality

 The relationship between the Penetrating Abdominal Trauma Index (PATI) and mortality is depicted in table 5.

Table 5; PATI score versus mortality

All patients with PATI scores of 35 or more died during or immediately after laparotomy. The average PATI score was 15, the median 12 and the range was 0-47. Forty (17.4%) patients sustained GSWA  had PATI score greater 25.

Seventeen patients (7.4%) died; eight of them died in the operating room from uncontrolled bleeding, while the other nine patients died later.  

Discussion

The evaluation and management of abdominal war wounds have seen great advances over the past century. In 1882 Simms emphasized the need of laparotomy in abdominal wounds, but the mortality rate remained 72%. It was not until end of World War I that operative management replaced expectant therapy and reduced the mortality rate to 53.5%. Since then the mortality rate from abdominal wounds dropped to 25% in World War II and 12% in the Korean conflict, reaching 8% at present (7).

This reduction in mortality rate was herald by the introduction of blood transfusion, the liberal use of antimicrobials, The prompt evacuation of casualties as well as improved per-, intra-, and post operative patient care (8).

Whether or not all patients with penetrating abdominal wounds should undergo surgical exploration has been the subject of several studies (9). Because some workers documented that mandatory exploration irrespective of clinical signs carries a high percentage rate of negative laparotomy (10,11).

Others mentioned that wound exploration under local anesthesia in the emergency department is now the preferred technique to establish if the peritoneum is entered (12).

 Our approach was to explore those patients with definitive peritoneal penetration, and we observed those stable patients with equivocal clinical signs in order to minimize the number of negative explorations. By this policy we performed only 15 negative explorations from 230 patients explored; in those negative exploration cases we found the bullet settled pre peritoneal and we could remove all of them. 

 The small intestine, colon, liver and stomach have been the most commonly injured organs in recent large series of abdominal gunshot wounds (13), such as in the current study. The most devastating and difficult injuries were those produced by multiple large pieces of shrapnels and were often with injuries to another body area.

 A major problem for patients who survive a traumatic injury is morbidity due to infectious complications (14). In this study wound infection occurred in 39 (17.0%) patients, which is not different from the 18% to 24% rate reported previously for similar studies (15). This relatively low rate of wound infection is difficult to explain; also serious wound infection was extremely rare.

 This was hypothesized that, those young basically healthy, resilient population possesses some form of herald immunity (16). The incidence of intraabdominal sepsis following penetrating abdominal trauma varies from 2.4% to 45.7% in published reports (17). In this work 11 (4.8%) patients had intraabdominal abscesses which are similar to other works. The use of broad spectrum perioperative antibiotics in combination with metronidazole and saline irrigation of the peritoneal cavity, contributed to the low incidence of post operative intraabdominal sepsis reported in this study. In those patients with infectious complications, like in other similar works (18, 19) we found prolonged duration of hospitalization.

In this work the average period of hospitalization for all patients was 12.5 days, ranged between 1 to 80 days while that with septic complications was 20.5 days ranged between 12 to 80 days (p< 0.001).

Previous studies have shown that in abdominal gunshot wounds, the mortality rate rise with the number of intra abdominal injured organs (20). Like the others we demonstrated a positive correlation between the number of intraabdominal injured organs and mortality.

However, the number of injured organs does not accurately quantify the overall severity of injury, for example, a patient with an isolated 3 cm. superficial liver injury is not severely injured as another with extensive liver parenchyma destruction, but both have one organ injured.

The PATI score is a more accurate method of quantifying the extent of damage to different organs and more valid index of overall severity of injury (5). In this study, the patients with PATI more than 35 died either during or immediately after operation. There was positive correlation between PATI and mortality, (p< 0.001).

Abdominal vascular injuries are among the most fatal injuries sustained by trauma patients (21,22). In this work 37 (16.1%) patients had intraabdominal big vessel injuries, eight of them died during operation from uncontrollable bleeding which was due to one or bigger vessel injuries.

The overall mortality rate in this work was 7.4 % which is surprisingly low. In most series the mortality from penetrating abdominal injury is close to 10% (1). The age of the injured persons, the efficient transportation system, the rapid surgical intervention after injury, the use of fresh blood for transfusion all are among the factors that contributed to minimize the low mortality rate in this work.

References:

Dr. AHMED KANDIL,

MB, BCh, MS, MD, PhD, AFSA (Gastro)

Consultant Surgeon

           Head of Gastrointestinal and Laparoscopic surgery department.

Shifa Hospital