Pattern, presentation and management of vascular injuries due to pellets and rubber bullets in a conflict zone.

BACKGROUND: Rubber bullets and pellet guns are considered non-lethal low-velocity weapons. They are used to disperse a mob during street protests. The present study was undertaken to analyze the pattern, presentation and management of vascular injuries caused by these weapons. PATIENTS AND METHODS: This was a prospective study of patients with features of vascular injuries due to pellets and rubber bullets from June 2010 to November 2010. All patients with features of vascular injuries due to these non-lethal weapons were included in the study. Vascular injuries caused by other causes were excluded from the study.
RESULTS: A total of 35 patients who presented with features of vascular injury during this period were studied. All of them were males. The mean age was 22 years. Fifteen patients were revascularized primarily, 19 patients needed reverse saphenous vein graft and, in one, patient lateral repair was done. There were two mortalities in our series. Wound infection was the most common complication. The amputation rate was around 6%.
CONCLUSION: Pellet and rubber bullets can cause serious life-threatening injuries. Vascular injury caused by these weapons need no different approach than other vascular injuries. Early revascularization and prompt resuscitation prevents the loss of limb or life.

INTRODUCTION

Historically, most patients who sustained serious arterial injury did not survive long enough to reach medical care providers. Those who did reach generally had minor wounds. With advancement in health care systems, and urbanization of the population, many seriously injured patients now arrive at hospitals. Even those with very serious vascular injuries (e.g., carotid vascular injury) may be salvaged.

The usual surgical approach to a major vascular injury was simply ligation of the vessel and amputation of the limb, e.g. during the American civil war popliteal artery injury resulted in a 100% amputation rate. In World War II, repair lowered the rate to 72%. During the Korean War, a policy of mandatory surgical exploration of all potential vascular injuries lowered the amputation rate to 32% for popliteal injuries.[1] A policy of performing arteriography on all suspected vascular injuries combined with evolving vascular repair techniques, during the Vietnam War, reduced the amputation rate of these injuries to 15%. With current diagnostic and vascular repair techniques, almost all of these injuries can be revascularized, although severely mangled limb may still need amputation. With an epidemic of vascular injury due to numerous causes (including Missile vascular injuries), this institute has got a vast experience in revascularizing such patients.[2345]

Non-lethal weapons used for dispersing the agitated mob during street protests are not supposed to cause lethal vascular injuries. However, during civilian unrest in 2010 in the Kashmir valley, these non-lethal weapons caused serious vascular injuries. These weapons were used to disperse the unruly mobs in street protests during this period. The present study was undertaken to analyze the pattern and presentation of these injuries.

PATIENTS AND METHODS

This was a prospective study of patients from 1st June 2010 to 30th November 2010. All patients with features of vascular injuries due to pellets and rubber bullets were included in this study. On arrival, patients were attended in the Accident and Emergency Department and were resuscitated as per the vital status of the patient. Initial resuscitation was started by basic A, B, C, (airway, breathing and circulation). Pressure bandaging and clamping of vessels by bulldog clamp was done to achieve control over bleeding vessel in case of obvious vascular injury. I/V fluids, e.g., crystalloids, colloids and blood transfusion after cross-matching through two wide bore cannulae at the available sites were given as per patient requirements. Urinary catheterization was performed in every patient. Associated injuries were addressed by the respective colleagues. Patients with vascular injuries were categorized into two categories depending on the clinical status.

Category 1 (Hard signs)

These include pain, pallor, pulselessness, parasthesias, paralysis, pulsatile bleeding and large or expanding hematoma. A patient who shows these signs will have a > 90% chance of vascular injury.

Category 2 (Soft signs)

These include a relatively diminished but palpable pulse, a non-expanding hematoma and peripheral nerve injury. Thirty percent to 35% of these patients will have vascular injury.

Patients in whom vascular injury was obvious and those who were hemodynamically unstable were directly transferred to the emergency theater and explored. Others were investigated by vascular Color Doppler before exploration. All patients received pre-operative antibiotic, a combination of third-generation cephalosporin and an aminoglycoside. We used these antibiotics because there was improper asepsis and contamination at the site of injury. All associated fractures (when associated) were fixed in the same sitting. The various surgical procedures performed were:

End to end repair (after debridement of the ends)

Use of reverse saphenous venous graft (segmental loss of > 2 cm)

Lateral repair (in case of lateral tear only).

All vessels were repaired by using continuous monofilament 6/0 prolene sutures. Venous graft whenever needed was taken from the saphenous vein of a non-injured limb. No temporary shunting was used. Fasciotomy was done as and when needed to relieve either existing compression or to avoid this from occurring in the post-operative period. Nerve injuries were assessed for immediate or delayed repair. Proper debridement of muscle tendon units was done and the repaired vessel was covered by a viable soft tissue cover in all settings. All patients received heparin intraoperatively. Heparin was continued in the post-operative period, which was followed by antiplatelet therapy. Venous injuries whenever identified were repaired after initial arterial repair. Patients were transferred to the Surgical Intensive Care Unit or the Postoperative Ward, where strict monitoring of vital signs was performed. On the second post-operative day, patients who made good progress were transferred to the main ward. All patients underwent Doppler studies before discharge. All patients were regularly followed-up in the outpatient department on a weekly basis for the first month, fortnightly for the next 3 months and 3-monthly thereafter.

The following were excluded from the study:

Patients with vascular injury other than that caused by pellets and rubber bullets

Vascular injury below the radial/ulnar and tibial arteries.

Finally, the entire data set was compiled and analyzed statistically.

RESULTS

A total of 35 patients were enrolled in this study. All of them were males. The mean age was 22 years. Popliteal artery was the most common vessel, followed by femoral artery [Table 1]. Sixty percent of the patients presented within 6 h of injury, while 40% presented after 6 h of injury. Contusion was the most common type of injury, followed by transaction. Lateral tear was present in three patients, one of whom had a carotid artery injury. Associated injuries were present in 57% of the patients [Table 2]. Long bone fractures were present in 40% of the patients. Reverse saphenous vein graft was performed in 54% of the patients. Fifteen patients underwent end to end anastomosis. Lateral repair was performed in one patient. He had a carotid artery injury. Venous injury was present in 11 patients. Nerve injury was identified in 11 patients. Wound infection was the most common complication, followed by graft occlusion (thrombosis). Wound infection occurred in 40% of the patients. Three patients developed graft occlusion. They were re-explored and thrombo-embolectomy was done. One of them ultimately ended up in amputation. The type of procedure (whether primary anastomosis or vein graft) did not influence the amputation rate. Amputation rate was 6%. The amputation rate was significantly higher in patients with long bone fractures and in those who reached the hospital after more than 6 h [Tables 3 and 4].

Table 1

Distribution of arteries involved

Table 2

Associated injuries

Table 3

Outcome as per timing of repair

Table 4

Effect of associated fracture on outcome of limb salvage

DISCUSSION

The study was performed keeping in view the civil war-like situation of Kashmir valley, in which there has been a steep rise in usage of rubber bullets and pellet guns. This study was undertaken to evaluate the pattern, presentation, management and outcome of these injuries in our hospital, the Sheri-Kashmir Institute of Medical Sciences Srinagar, the only tertiary care center in the whole state of Jammu and Kashmir for management of such injuries. Keeping in mind the nature and severity of these injuries, that not only can they disable but also kill a patient if not treated immediately, the study was performed to analyze the management profile of these injuries. All patients were young males involved in these street protests. Popliteal artery was the most commonly affected vessel, followed by the femoral artery. The distribution of arterial injury in our series was comparable to that in other series.[678] These series also had an almost similar arterial distribution.

Contusion was the most common type of injury, followed by transaction. This was probably because of the low velocity impact of the pellet and rubber bullet. Others had similar results in their series.[910] However, all these types of comparisons depend upon the mechanism of trauma, whether it was high velocity or low velocity trauma. In our series, most of the patients were injured by low velocity trauma.

Most patients were diagnosed by careful clinical assessment. In doubtful cases, pre-operative vascular Color Doppler studies aided the diagnosis. Doppler study is easy and quick to perform in doubtful cases without much delay in treatment. We did not perform angiography because of its invasiveness and time consuming process; its use in this type vascular injury is limited as first-line investigation. However, it is a useful tool for the diagnosis of delayed vascular injuries (missed injuries). Facility of on-table angiography is not available in our setup. In most of the series, careful clinical assessment was the most common method of diagnosis.[811] Patients with vascular injury were most often treated with reverse saphenous venous graft or end to end anastomosis. We performed end to end anostomosis only in those patients where the two ends could be approximated easily after proper mobilization and debridement of the two ends. End to end anastomosis was fashioned in 42% of the patients while vein graft was used in 54% of the patients. With advanced techniques of vascular repairs and understanding the pathophysiology of vascular injuries, end to end anastomosis is the preferred treatment provided conditions are favorable. However, it is customary not to perform anastomosis under tension, and the saphenous venous graft must be used to bridge any segmental loss.

Associated skeletal trauma presents a challenge to the surgeon because skeletal trauma increases the morbidity rate such as amputations or even mortality. Injury caused by high velocity trauma is usually associated with soft tissue loss, damage to the collateral circulation and venous injuries as well. Longer surgery as well as excessive manipulation of tissue due to fixation of bony fragments adversely affects the outcome. During bony stabilization, due respect should be given to the surrounding tissue and the cold ischemia time should be calculated accordingly. In our series, associated fractures have a significant impact on limb salvage. Those without fractures had limb salvage of 100% versus 85% of those with fractures. Associated skeletal trauma, particularly femur and tibial fractures, were major causes of morbidity in our series. We made fixation of fracture mandatory in the same sitting. Any vascular injury with concomitant skeletal trauma should be considered as a very high risk for limb loss and hence should be dealt with very meticulously and carefully, especially in those with associated spinal injuries such as cord compression, contusion or laceration. Internal fixation was done in four patients while external fixation was done in the remaining of the 10 patients.

There were 11 patients having associated venous injuries (32%). Venous injuries are mostly diagnosed on exploration of the wound. Venous injury should be repaired unless the situation demands otherwise. Ligation works on the principle of collateral channels, but, when in doubt, every attempt should be made to restore the continuity of the vessel. Our series had 32% associated venous injuries correlating very well with reports of other centers.[612] We always ensured repair of any major vein, as ligation alone would jeopardize arterial perfusion because of Compartment syndrome.

Nerve injury was an associated injury in 11 patients. Seven of them were repaired primarily. Nerve repair was done using 8/0 prolene by a plastic surgeon. In the remainder of the patients, the cut ends of the nerves were identified and tagged with prolene and approximated as much as possible to avoid retraction and for later identification of the nerve. Our results were comparable to those of other series.[713]

Vascular injuries were defined as early or late depending on whether they presented before or after 6 h post injury, resulting in a delay in revascularization from the time of trauma. This is the cold ischemia time, which is important with regard to the viability of the tissue, thrombus formation and distal patency of the vessel. Also, it indirectly affects the hemodynamic stability of the patients. In our study, 14 patients (40%) had a time lag of > 6 h and 21 patients (60%) were revascularized within 6 h or less. This is a reflection of early transportation and efficient management with increasing facilities and technology. In cases where blood flow was re-established within 6 h, 100% of the limbs were salvaged, while only 86% of the limbs could be salvaged in case of delay of > 6 h. Vascular repair should be attempted in every case, whether early or late. With meticulous repair, proper use of fasciotomies and proper wound care, the results may be satisfactory. Of course, proximal and distal thromo-embolectomy are a necessity, and more so is clearly defining the injured sites of these vessels by deskeletonizing the proximal and distal stumps or the site of lateral trauma before any repair is attempted.

Of the 34 limbs injured in this series, 32 were salvaged (94%), which is comparable to the results of other series.[671415]

CONCLUSION

Early intervention and prompt resuscitation should be done. No time should be wasted for time consuming investigations. Associated trauma to bones, lag time > 6 h and hemodynamic instability should be considered high risk factors among vascular injuries. The technique of reconstruction, whether primary anastomosis or saphenous vein graft, should be meticulous and fastidious, without any amount of tension on the anastomosis site. Tissue coverage of anastomosis by muscle, rotation flap, etc., prophylactic fasciotomy when indicated and good post-operative care are keys to success.