Problem Statement

Of nearly 10,000 sloth bears (Melursus ursinus) in India, nearly 3,000 lives in dens of Chhattisgarh, the largest in India.6 This species is included in Schedule I of the Indian Wildlife (Protection) Act 1972 and International Union of Conservation of Nature (IUCN 2010). This forest land is in patches, interspersed with agricultural land with human habitat. The sloth bears live in a den during cold weather and come out during summer and early springs during dusk and dawn (crepuscular) for food collection. Sloth bears mostly feed on ants, termites, honey, and fruits. Secondarily bears are known to raid crops in agricultural farms. In Chhattisgarh, when the temperature rises above 40°C during summers, fields are mostly devoid of crops, and most tribal occupants invade forests for fruits and their livelihood on rubber plants and tendu leaves. Additionally, tribal populations routinely encroaches forests during dusk and dawn due to a lack of proper sanitation facilities explaining the reasons for most of the conflicts during these hours of the day. This encroach creates competition and conflicts with sloth bears. The incidence of bear mauling is on the rise in Chhattisgarh. There were 157 such incidents during 2018 to 2019 with a 35% rise to 202 incidents in the year 2019 to 2020.1 In a study published by Bargali et al in 2005, there were 137 such incidents with the loss of 11 humans, and two beer lives in 32 months in only one forest division.7 As per media reports, 215 human had lost their lives due to animal mauling from 2005 to 2014.6

The Conflict: Man versus Wild

According to Rajpurohit and Krausman the sloth bear is one of the most dangerous wild animals.8 They are even known for unprovoked attacks.9 In the present series, 25% of the attacks were unprovoked. Their attacks on humans are responsible for 67% of all animal attacks, with death to injury ratio of 1:14.3.8 Average sloth bears can grow up to 6 feet, gain 140 kg weight, run up to 48 km/h, and have strong jaws and teeth along with long and sharp nails.5 The human body’s limits cannot overpower them by any means. The brutal force by bears can shatter any skull, and the pattern of craniofacial injuries is unmatchable and devastating. The conflicts usually occur when neither of both aware of proximity and sudden appearance leads to a panic situation. The bears do so in an attempt to protect their cub, food, or territory. Humans are only left with options like a fight, run, or climb the tree; unfortunately, all are in bears’ domains. The only chances of survival are left on mercy by the bear, severity of the injury, and timely reach to the proper medical facility.

Like the present series, mostly males had been found victims in all series. The middle age group (30–50 years) is most commonly affected due to increased outdoor activities. Bargali et al stated most encounters during dusk and dawn but some have reported during the daytime.7 In the present series, a total of 75% of encounters was during dawn and dusk due to human encroachment in forests for sanitation. Rasool et al and Shah et al found most attacks sudden and unprovoked, unlike the present series.2 5 We believe that most animals have possessive behavior and only offend when compromised for the safety of themselves and cubs, food, or territory. To restrict bears to the forest territory by providing food and water opportunities, the Chhattisgarh government has started the “Jamvant” Project. The state government also bears the burden to provide compensation aid to the victims.6

Spectrum and Mechanism of Injuries

The first reported surgical management of such injuries dates back to 1891 by Moir.10 The data of structures injured varies among reports, but many had found face as a primary target. In a quest to incapacitate their victims and overcome counter attack, bear targets on craniofacial structures which comprise 19% of injury in one study, while the other published study from Chhattisgarh reported collectively 70% injury to face and scalp with only two head injury cases.11 The injury to the eyeballs makes the victim blind to retaliate.12 The brutal force applied by the bear led to multiple shattering of facial bones involving the maxilla, zygoma, mandible, nasal bones, orbit, frontal, and parietal calvarias along with extensive soft tissue injury.5 It is common to observe tissue loss to a certain extent. The actual incidence of neurological injury is unknown. Out of a total of 79 patients admitted at our institute, 28 (35.44%) had a TBI. The actual incidence figures may vary as many victims with minor injuries had not been referred to our center or some would have succumbed either at the scene or in transport. As the frontal region is in direct view of the bear, frontal scalp lacerations, bone fractures, and parenchymal contusions are more common. Temporal, occipital, and skull base were less commonly seen fractured.3 5 13 Overall, the spectrum of TBIs matches as of due to road traffic accidents except for higher incidences of skull fractures (especially depressed type) and lower incidences of diffuse axonal injury. Other structures commonly seen injured are limbs (55%) in futile defense attempts. Vascular injuries are also reported in 15 of 212 cases by Wani et al.14

Management

These conflicts occur in remote areas where neurosurgical facilities are still a dream. The majority of these victims were initially taken to the primary health center where the only possible surgical means are first aid. Many of our patients received were wrapped in piles of bandage without primary suturing due to extensive soft tissue damage puzzling the means of repair. All these patients need vitals stabilization, hemostasis, and robust tissue approximation before radiological evaluation.

Another critical issue is airway protection in the setting of severe damage to facial structures leading to inadequate seal and support for mask during bag and mask ventilation. We use cotton mops to provide a seal for slight leak and saline filled surgical gloves to bridge larger gaps. These patients have a high risk of aspiration due to the pooling of blood and saliva in the oropharynx, along with soft tissue damage and edema.15 Even the suction and intubation are challenging and may require emergent tracheostomy. Video laryngoscope is a useful aid for assisted intubation. Adequate pain relief is of paramount importance and requires opioid analgesics. Often these patients lose a large pool of blood at the scene and require transfusions. After proper resuscitation, the optimal imaging modality is two-dimensional (2D) and three-dimensional (3D) craniofacial noncontrast CT scan for assessment, planning, and to decide urgency for intervention.

These devastating injuries require a multidisciplinary team approach consisting of neurosurgeons, plastic and maxillofacial surgeons, anesthetists, and intensivists. In an attempt to restore optimal neurological and aesthetic sense, long operative hours fiddling up with leftover devascularized tissue fragments is a necessity. Raising scalp flap for cranial intervention in a customized manner is often not possible, and scalp incisions need to be tailored based on patterns of scalp lacerations and the size of craniotomy required. The main trunk and branches of the superficial temporal artery must be preserved as carefully as possible. These patients require elevation and excision of shattered bone fragments, removal or hematomas, and contusions, and watertight but lax dura repairs from a neurosurgical perspective. We prefer to use either pericranial fascia if possible or fascia lata graft for dura repair instead of artificial substitutes due to infection concerns. We also tend to avoid placing Gelfoam over dura as much as possible. We do not use titanium mesh during the first surgery to cover bony defects due to similar reasons. The scalp is essentially sutured in an interrupted manner rather than continuous. We use prophylactic antiepileptic drugs as a protocol in all cases of parenchymal lacerations.

Aesthetic surgeons have a tough time to find means of tissue approximation after maxillofacial fractures are stabilized with implants. Regions of excess tissue loss segment require rotation or pedicle flap for coverage. In a delayed presentation with infection and devitalized tissue, the only debridement should be considered and primary closure is withheld till the resolution of infection. Some patients require multiple-stage operations due to the complexity of defects. Due to injury to the associated facial nerve, even with good tissue approximation, functional results are suboptimal,16 and such disfigured faces retract themselves from social appearances and experience posttraumatic stress disorders, the importance of psychiatric management cannot be undermined.17 Mild and moderate cognitive dysfunctions on MMSE were seen in six cases (21.42%) in each group in the present study. To the best of our knowledge, this is the only study which has assessed cognitive dysfunction using MMSE score till date in bear maul injuries.

These wounds are often full of contamination with gram-positive (Streptococcus and mostly Staphylococcus) and gram-negative (E. coli and Enterobacter) organisms.18 The other organisms isolated from cultures were Serratia, Enterococcus, Bacillus, Aeromonas, Neisseria, Prevotella, and Propionibacterium.19 They need broad-spectrum antibiotics coverage initially and subsequently based on cultures.20 Wounds need to be debrided, irrigated copiously with normal saline, hydrogen peroxide, and povidone–iodine to reduce contamination. We practice the local use of chloromycetin irrigation before closure in addition to systemic antibiotics. The SSI rate due to bear maul in the present study is higher than our other TBI cases due to road traffic accidents (28.57% vs. 11.13%). Most of the articles had advocated using penicillin and cephalosporins for broad-spectrum coverage, and Pukar et al found garenoxacin and oral des-fluoroquinolone helpful.21 We believe broad-spectrum coverage should include gram-negative and anaerobes as well. Our policy is to start piperacillin or tazobactum and aminoglycosides and metronidazoles at first go and modify once aware of culture and sensitivity.

The use of postexposure tetanus and antirabies prophylaxis is a common practice and is recommended.22 Some surgeon even locally infiltrates human rabies immunoglobulin before closure.23 In our series, we avoid local infiltrations. We administered both human rabies immunoglobulin (HRIG) and antirabies vaccine on day 0 and repeated administration of antirabies vaccine on day 3, 7, and 14. Anesthetic drugs, especially ketamine, lessen the effect of the antirabies vaccine.24 25 In an ideal case scenario, one should wait for surgery and anesthesia up to 1 week after inactive vaccination and up to 3 weeks after live vaccination.26 Due to the emergency nature and concerns about infections, one cannot help instead, operate at the earliest opportunity. None of our patients developed rabies or tetanus in the postoperative period.

The neurological outcome of these patients is generally satisfactory and primarily depends on the severity of the head injury. The favorable outcome (MRS: 0–2) in the present series was seen in nearly two-thirds (64.28%) of patients, and nearly three-fourths (78.57%) did fare (normal or mild cognitive dysfunction) on MMSE. From an esthetic perspective, the final impression looks rewarding, and they live with deformity and morbidity. Causes of death at the scene are primarily due to hypotension, aspiration, and cranial and cervical injuries.27 In patients who manage to reach the hospital live and stable, the primary cause of death is cranial injuries.3 4 11 In the literature review, we only found a single death secondary to septicemia.28 There was no life lost in our cohort.

Cranioplasty after decompressive craniectomy in these patients also needs special consideration. We prefer to defer cranioplasty until wound healing is satisfactory without signs of infection, and optimal neurological status is achieved. A total of 10 cranioplasties was performed at an average interval of 3.8 months in the present study. As mentioned previously, scalp flaps of these patients are often tailor made; incising scalp over previous scars and raising flap for cranioplasty need meticulous dissection avoiding injury to underlying brain parenchyma. We prefer to use titanium mesh for cranioplasty.