Profile of missile-induced cardiovascular injuries in Kashmir, India

Abstract

Background:

Missile cardiovascular injuries have taken an epidemic proportion in Kashmir valley since the eruption of militancy in 1990. Present study was undertaken to analyse the pattern, presentation and management of missile cardiovascular injuries.

Patients and Methods:

Three hundred and eighty-six patients with missile cardiovascular injuries since Jan 1996 to Oct 2008 were studied retrospectively. All patients of cardiovascular injuries due to causes other than missiles were excluded from the study.

Results:

All patients of missile cardiac injuries were treated by primary cardiorrhaphy. Right ventricle was the most commonly affected chamber. Left anterior thoracotomy was most common approach used. Most of the patients of missile vascular group were treated by reverse saphenous vein graft or end-to-end anastomosis. Most common complication was wound infection (20.83%) followed by graft occlusion (1.94%) in missile vascular group. Amputation rate was 4.66%. Amputation rate was higher in patients with delay of >6 hours and associated fractures.

Conclusion:

Missile cardiac injuries should be operated early without wasting time for investigations. Clinical status at arrival, time interval till management, nature of injury and associated injuries, tell upon the mortality. Missile vascular injury needs prompt resuscitation and revascularization at the earliest. Time interval till revascularization and associated fractures has a bearing on mortality and morbidity.

INTRODUCTION

Most cardiovascular trauma in military conflicts occurs from fragmentary missiles such as artillery, rockets, grenades and bombs. Experimental studies of high-velocity wounds show that a temporary cavity can be created nearly 30 times as large as permanent residual tract.[1] This temporary cavitational effect injures tissue beyond the actual path of missile. It is estimated that 80-90% of patients with gunshot wounds of heart do not reach hospital.[2] The standard approach has been to repair the lacerations using mattress sutures while controlling hemorrhage with the finger on heart. Emergency temporary control of hemorrhage from cardiac laceration can be achieved with the use of skin stapler.[3] Following stabilization of the patient, the staples can be removed after definitive suture repair is performed in operating room. Hemostatic sealants such as Floseal, etc, offer significant promise as additional tool in the surgical armamentarium when dealing with laceration to the heart.[4] Regardless the approach used, care must be taken to avoid injury to coronaries. Vascular repair was first successfully performed in the early 1900s. The usual surgical approach to a major vascular injury was simple ligation of the vessel and amputation of limb. During Civil War, popliteal artery injury resulted in 100% amputation rate. In World War II, repair lowered the rate to 72%. During Korean War, a policy of mandatory surgical exploration of all potential vascular injuries lowered the amputation rate to 32% for popliteal injuries.[5] A policy of performing arteriography on all suspected vascular injuries combined with evolving vascular repair techniques, during 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. Present study was undertaken to evaluate the profile and management of missile cardiovascular injuries.

PATIENTS AND METHODS

This retrospective study comprised of data acquired from Jan 1996 to Oct 2008. During this period a total of 386 patients of missile cardiovascular injuries were admitted to our center. Twenty-six patients were operated for missile injuries to the heart. Three hundred and sixty patients were operated for missile vascular injuries. Patients who were pronounced dead on arrival to the hospital after missile injuries to precordium and patients with penetrating cardiac injuries or vascular injuries due to causes other than missile injuries were excluded from the study.

The patients of cardiac injuries were categorized into three groups depending on physiological parameters.

• Group I: (Stable) Mean blood pressure 62±2.3SD, alert, no respiratory distress.

• Group II: (Shock) Mean blood pressure of 48±4.4SD, conscious, mild respiratory difficulty.

• Group III: (Agonal) No recordable pressure, semiconscious, gasping.

Patients having systolic blood pressure of less than 90 mmHg or mean blood pressure of less than 60 mmHg were categorised as Group II i.e., shock.

All these patients were operated in the emergency operation theatre as emergency room thoracotomy is not available in our hospital. All patients were managed by cardiorrhaphy using 2/0 or 3/0 silk or prolene. In addition, ligation of terminal coronary branches was done in three patients. All procedures were performed without cardiopulmonary bypass.

Patients of vascular injuries were initially resuscitated in emergency reception and were categorised into two groups based on clinical examination:

Category 1 (Hard Signs): Include pain, pallor, pulselessness, parasthesias, pulsatile bleeding and a large or expanding hematoma.

Category 2 (Soft Signs): These include a relatively diminished but palpable pulse, a non-expanding hematoma and a peripheral nerve injury.

Patients of category 1 were directly shifted to emergency theater and explored. Patients of category 2 were subjected to vascular Doppler before exploration.

All patients received a third generation Cephalosporin and an amino glycoside at induction of anesthesia. Injured vessel was exposed after proximal and distal control of bleeding. Extent of injury was assessed. Patients with >2.5cm segmental loss was revascularized by reverse saphenous vein graft. Thorough debridement of soft tissue was done. We did not use temporary vascular shunts. None of our patients had more than one peripheral vascular injury.

We used standard techniques for management of missile vascular injuries i.e., resuscitation with fluids and blood, properly defining the extent of vascular injury, proper control of bleeding using different types of vascular clamps, proper freshening and denuding the edges of injured vessel, tension free repair by using graft whenever needed, small lacerations treated by lateral repair only, bony injury (fractures) taken care of, in the same sitting, fasciotomy was performed as and when needed and systemic anticoagulation using heparin in perioperative period followed by Aspirin or Clopidogrel.

Different surgical procedures like direct end-to-end anastomosis, saphenous vein graft interposition and lateral repair were performed for revascularization. Heparin was used in perioperative period and later on patients were shifted to oral clopedogrel and aspirin. Liberal fasciotomy was performed in most of the patients whenever indicated on clinical assessment. All fractures were fixed before vascular repair. Hospital stay was 12-15 days depending upon other comorbid states or other organ injuries. Statistical analysis was done using Fisher's exact test with SPSS software (Spss USA) with 95% confidence interval.

RESULTS

Mean age of patients was 32±4.8SD. There were 322(83.41%) males and 64(16.58%) females. Twenty-six patients had missile cardiac injury and 360 patients had missile vascular injury.

The patients of missile cardiac injury were received in the Accident and Emergency Department between 24 minutes and 8.6 hours after the injury (mean 4.1 hours). There were seven (26.92%) patients in Group I, eight (30.76%) in Group II and 11 patients in group III. Eighteen patients (69.23%) underwent left anterior thoracotomy, sternotomy was done in four (15.38%) and in four (15.38%) both thoracotomy and sternotomy was needed. Sixteen patients had right ventricular injuries, five had left ventricular injuries, four had right atrial injuries and one had injury in left atrium. Clinical status at admission had a bearing on the outcome and the results are demonstrated in the Table 1. Ten patients (38.46%) in our series had firearm injuries (Gunshot injuries) and the remaining 16(61.53%) had pellet or splinter injuries to the heart due to the bomb blasts. Five (50%) patients survived in the gunshot group while nine 56.25% survived from the splinter/pellet group. Isolated cardiac injuries were noted in 61.53% (16/26) of the patients. Ten patients (38.46%) had associated other organ injury, some having injury at more than one site. The survival in patients with isolated cardiac injury was 61.11%, while it was only 37.50% in those with associated injuries. Single-chamber injury was noted in 84.61% of the patients. The survival in these was 63.63%. However, none of the four patients with multiple chamber injury in our series survived. Ten complications were noted in the series. One patient was re-explored for excessive bleeding and a missed right ventricular perforation was repaired. The details of the complications noted are shown in Table 2.

Table 1.

Outcome depending upon clinical status

Table 2.

Complications in resuscitated patients

The patients of missile vascular injuries were received in Accident and Emergency Department between 30 minutes to 24 hours after the injury. Three hundred and one patients were revascularized within 6 hours of injury (83.61%). Popliteal artery was the most common vessel involved (42.50%) followed by brachial artery (23.60%).

Table 3 shows the arterial distribution in our series. Right side was involved in 58.05% of patients. Transection was the most common type of injury followed by laceration (43.88% vs. 40.27%). Most of the patients were diagnosed by critical clinical assessment 244(67.77%). Doppler aided in diagnosis of rest of the patients. Most of the patients were revascularized by using venous graft or end-to-end anastomosis (52.22% vs. 39.16%). Lateral repair was done in 8.61% of the patients. Venous injury was associated in 19.44% of patients [Table 4]. Liberal fasciotomy was performed in 65% of patients. Associated skeletal trauma was present in 40% of the patient. Nerve injuries were associated in 19.44% of the patients [Table 5]. Only 18 primary nerve repairs were done. Rest of the nerves were repaired in the second setting. Wound infection was the most common complication followed by graft occlusion and thrombosis. Amputation rate was 4.66% in peripheral missile vascular injury. Amputation rate was not influenced by type of injury, type of repair or presence of associated venous injury. However, associated skeletal trauma increased the amputation rate [(P value =0.036) for limb salvage (significant) and (P value=0.65) for death rate (not significant) using Fisher's exact test with SPSS software with 95% confidence interval] [Table 6]. Another important factor influencing amputation rate was, delay in revascularization since time of injury. Patients who were revascularised after 6 hours of injury had higher amputation rates [(P value=0.045) for limb salvage (significant) and P value=0.061 for death rate (not significant) using Fisher's exact test with SPSS software with 95% confidence interval] [Table 7]. Eighteen patients underwent amputation. Nine patients had severe functional loss because of delayed revascularization after severe trauma to neurovascular bundle.

Table 3.

Distribution of artery involved

Table 4.

Distribution of associated venous injuries and their management (n=70)

Table 5.

Distribution of associated nerve injuries and their management (n=70)

Table 6.

Effect of associated fracture on outcome on limb salvage

Table 7.

Outcome as per timing of repair

DISCUSSION

Cardiothoracic injury causes 25% of deaths immediately following trauma, and the majority of these fatalities involve cardiac or great vessel injury. Penetrating cardiac trauma represents an increasingly important form of trauma due to more use of firearm and bombs in civilian violence. The management of penetrating cardiac injury has evolved from conservative management during World War II to aggressive early surgical intervention.[6–8] Penetrating cardiac trauma presents with two clinical manifestations, exsanguinating hemorrhage or pericardial tamponade. Pericardiocentesis in patients with acute tamponade is unreliable[6,7] and was not used in our series. All patients were subjected to early surgical intervention in the emergency operation theater.

The overall survival in our series was 53.84% (14/26). This is comparable with survival rates reported by others for gunshot and missile cardiac injuries.[9,10] In our series, survival of patients with pellet splinter injuries to the heart was found to be better than with gunshot injuries (56.25 vs. 50%). Variable mortality rates ranging 12-81% have been reported after gunshot wounds to heart by others.[9,11,12] In 2006, a retrospective study of penetrating cardiac injury in South Africa found 81% mortality among the 21 patients who sustained gunshot wounds to the heart.[10]

The clinical status at admission has a significant bearing on the outcome. Only one patient in our series who was stable on admission died while eight out of 11 who were admitted in an agonal state (Group 111) died. This high mortality of 72.72% in these agonal patients could be due to the lack of facilities for emergency room thoracotomy in our hospital. In the present series, survival was better in patients with isolated cardiac injury as compared to those who had associated injuries (61.11 vs. 37.50%). However, previous studies have shown that risk of mortality was not higher in patients with associated injuries.[11] None of the patients in our series with multiple chamber injury survived. However, the risk of death was not found to be different between patients sustaining single or multiple cardiac injuries in the series by Degiannis.[11]

The most commonly involved chamber was found to be the right ventricle in 61.53% of the patients followed by left ventricle, right atrium and left atrium. This is easily explained by the fact that the right ventricle covers the greatest part of the anterior chest wall and represents 55% of the anterior cardiac surface. In a review of 1,802 cases of penetrating cardiac trauma from 20 reports, the right and left ventricles were injured 43% and 33% of the time, respectively. The frequency of involvement of the other chambers is directly proportional to the area of the chest wall they cover.[13] The coronary arteries are reported to be involved in 3.1-4.4% of penetrating cardiac injuries.[14–16] In the present series they were involved in three (11.53%) of the cases. Owing to its anatomically anterior placement, the left anterior descending artery is the most frequently involved, being injured in 87.5% of cases of coronary artery lacerations.[16] The right coronary is the second most commonly involved.[14] In the present series, only two patients had main coronary artery laceration both involving the left anterior descending branch. All the injuries to the heart were repaired with interrupted sutures alone. Teflon pledgets have been used to assist in anchoring the sutures and prevent sutures from causing further myocardial damage.[17] However, they were not used in our series.

Murphy[18] in 1896 did first successful vascular end-to-end anastomosis in a man. Because of improvement in vascular repair techniques, accompanied by substantial progress in anesthesia, blood transfusion and use of antibiotics, improved outcome in vascular injuries was obtained in Korean conflict as compared to World War II.[19,20] Most recent studies have documented the continuous improvement in limb survival after vascular injuries, a reflection of primary repair or interposition graft. A cardinal operative principle in managing vascular trauma is to obtain proximal and distal control of injured vessel before entering surrounding hematoma.[1] In extremities as in neck, control is achieved using standard extensile vascular exposure techniques.[21,22]

Early recognition of missile vascular injury is a must for successful outcome. Diagnosis is usually by critical clinical assessment aided by vascular Doppler whenever necessary.

Although popliteal vein was successfully ligated by many authors,[23–26] but we advise repair of popliteal vein which enhances the success of arterial repair by relieving acute venous hypertension, compartment syndrome and edema. However, arterial repair precedes venous repair to decrease ischemia time. Associated venous injury did not increase the amputation rate as reported by some authors. The significant factor associated with increased limb loss is the time lapse between injury and revascularization.[24,27–33] This is because of progression of muscle ischemia and small vessel thrombosis that prevents successful outcome of repair. This was true in our patients as well. Another important factor contributing to limb loss is associated fractures.[30,34] In our study associated fractures had a significant impact on the amputation rate. We used fasciotomy very often and liberally as advised by many authors.[27] This have favored the prognosis in our series as well having reduced the amputation rate remarkably to 4.66%.

In our study, wound infection was very high because of contamination and improper asepsis at the site of injury, at the time of mass casualties.

CONCLUSION

Missile cardiac injuries should be operated early without wasting time for investigations. Clinical status at arrival, time interval till management, nature of injury and associated injuries will tell upon the mortality. Missile vascular injury needs prompt resuscitation and revascularization at the earliest. Time interval till revascularization and associated fractures has a bearing on mortality and morbidity.