9
Clinical Ballistics: Surgical Management of Soft-Tissue Injuries—General Principles*
Donald Jenkins, Paul Dougherty, and James M. Ryan
168
The goal in treatment of soft tissue wounds is to save lives and limbs, pre- serve function, minimize morbidity, and prevent infections through early and aggressive surgical wound care far forward on the battlefield.
* The opinions expressed herein are the private views of the authors and are not to be construed as official or reflecting the views of the US Department of the Army, or the US Department of the Air Force, or the US Department of Defense.
Treat the wound, not the weapon.
All war wounds are contaminated and should not be closed primarily
Presurgical care is aimed primarily at prevention of infection. Typically, a sterile dressing should be placed in the field as soon as possible, and this dressing should be left undisturbed until surgery. A one-look soft tissue exam may be performed upon initial presentation to the definitive treat- ment facility because the infection rate increases with multiple examina- tions prior to surgery. Initial wound cultures are unnecessary and a waste of valuable resources. Antibiotics should be administered for all penetrat- ing wounds as soon as practical, preferably even in the tactical field sce- nario, if possible. In these war wounds, antibiotics are therapeutic, not prophylactic, but keep in mind that antibiotics are not a replacement for surgical treatment.
Surgical wound-management priorities involve understanding that life- saving procedures should be done before limb and soft tissue wound care.
In order to save limbs, vascular repair and compartment release must be undertaken expeditiously, even simultaneously, if possible. In order to best
minimize or prevent infection in war wounds, wound surgery needs to be accomplished within 6 hours of wounding, sterile dressings must be applied properly and maintained, antibiotics need to be well utilized, and fractures must be immobilized.
Superficial penetrating fragment (single or multiple) injuries usually do not require surgical exploration. Simply cleanse the wounds with antisep- tic and scrub brush. Nonetheless, depending upon location and clinical pre- sentation, maintain high suspicion for vascular injury or intra-abdominal penetration. Avoid “swiss cheese” surgery (in an attempt to excise all wounds and retrieve fragments).
Primary Surgical Wound Care
The techniques important to master in primary surgical wound manage- ment include the proper use of limited longitudinal incisions, the excision of all foreign material and devitalized tissue, copious wound irrigation, splinting extremities for transport to improve pain control, leave wounds open (no primary closure of war wounds), and proper use of antibiotics (Figure 9-1).
As seen in the accompanying graphics, the mainstay of surgical technique is the use of limited longitudinal incisions as originally described by Larrey for the purpose of debridement (see box).
Débridement (unbridling or unleashing)
The term was introduced by Baron Dominique Jean Larrey (1766–1842), Surgeon to Napoleon’s Imperial Guard. He used it to describe the process of laying a wound open to facilitate removal of bullets, bits of loose cloth, detached pieces of bone, and soft tissue. He and his contemporaries did not excise tissue in the modern sense, and his procedure was much less extensive than the formal wound excision practiced today.
Wounds are extended with incisions parallel to the long axis of the extremity to expose the entire deep zone of injury. At the flexion side of joints, the incisions are made obliquely to the long axis in order to prevent the development of flexion contractures. The use of longitudinal incisions, rather than transverse ones, allows for proximal and distal extension, as needed, for more thorough visualization and debridement.
In the current day, we have extended the technique to include wound excision of nonviable tissue. For skin, a conservative excision of 1 to 2 mil- limeters of damaged skin edges is performed. Excessive skin excision is
Figure 9-1. Technique of debridement in soft-tissue wounds. (A) Line of incision and excision of traumatized skin. (B) Excision of traumatized fascia. (C) Excision of devitalized muscle. (D) Technique of wound dressing. (From Emergency War Surgery, 2nd US revision. NATO Handbook 1988. US Government printing office, Washington, DC).
avoided; questionable areas can be assessed at the next debridement. For fat, damaged contaminated fat should be generously excised. For fascia, one must bear in mind that the damage to the fascia is often minimal relative to the magnitude of destruction beneath it. Shredded, torn portions of fascia are excised, and the fascia is opened widely through longitudinal incisions to expose the entire zone of injury beneath. Complete fasciotomy is often required.
Wound Excision
Removal of dead muscle is important to prevent infection (Figure 9-2 shows wound excision of a high-energy gunshot wound of thigh). Accurate initial assessment of muscle viability is difficult. Tissue-sparing debridement is acceptable if follow-on wound surgery will occur within 24 hours. More aggressive debridement is required if subsequent surgery will be delayed for more than 24 hours. Sharply excise all nonviable, severely damaged, avascular muscle. Color, contractility, consistency, and capillary bleeding (circulation)—the “4 Cs”—may be unreliable for initial assessment of
Figure 9-2. High-energy wound of thigh. (Reproduced with permission from Ryan JM, Ballistic Trauma: Clinical Relevance in Peace and War. London: Arnold;
1997:113).
muscle viability. Color is the least reliable sign of muscle injury. Surface muscle may be discolored due to blood, contusion, or local vasoconstric- tion. Contraction is assessed by observing the retraction of the muscle with the gentle pinch of a forceps. Consistency of the muscle may be the best predictor of viability. In general, viable muscle will rebound to its original shape when grasped by a forceps, whereas muscle that retains the mark has questionable viability. Circulation is assessed via bleeding tissue from a fresh wound. Transient vasospasm, common with war wounds, may not allow for otherwise healthy tissue to bleed.
Bones, Nerves, and Tendons
For bone, fragments with soft-tissue attachments and large free articular fragments are preserved. Remove all devitalized avascular pieces of bone smaller than thumbnail size that have no soft-tissue attachment. Deliver each of the bone ends of any fracture independently, clean the surface, and clean out the ends of the medullary canal. Nerves and tendons do not require debridement, except for trimming frayed edges and grossly destroyed portions. Primary repair is not performed at the initial debride- ment. To prevent desiccation, use soft tissue or moist dressings for cover- age. Only minimal debridement of a vessel is required for a successful repair and limiting infection.
Management of Vascular Injury
Major artery and vein damage can pose special difficulty. Smaller vessels may be ligated, but major vessels should be repaired (for closer examina- tion, see Chapter 18). Where possible, the ends should be trimmed and sutured. If any tension is likely to develop, a reversed vein graft may be inserted to bridge the gap and the repair, then covered by healthy muscle.
The rest of the wound should be left open for delayed primary closure. Syn- thetic grafts are best avoided in the field surgical environment—the risk of graft failure due to sepsis is an ever-present threat. However, a temporary plastic shunt may be employed to revitalize tissue distal to the site of injury prior to definitive repair. In combined arterial and venous injury, concomi- tant shunting of both vessels may be necessary. Temporary shunting has an important place where major vascular injury is associated with complex fractures of long bones. Here, blood flow is re-established via the shunt(s), and the fracture is reduced and immobilized using an external fixator, after which definitive vascular repair is undertaken.
Irrigation and Wound Dressing
Irrigation serves to remove small particulate matter, clots, bacteria, debris, and other foreign matter. Following surgical removal of debris and non- 172 D. Jenkins et al.
viable tissue, irrigation is performed until clean. Several liters of fluid are required and varies based on degree of contamination, age of wound, and surgeon experience. While sterile physiologic fluid is preferred, do not deplete resuscitation fluid resources: one may use potable water as an alter- native. According to preference, there may be additional efficacy if the last liter of irrigant contains antibiotics.
In the civilian setting, local soft-tissue coverage is often required in complex wounds with extensive tissue loss. The development and rotation of flaps for this purpose should not be done during primary surgical wound care in the field environment. Local soft-tissue coverage through the gentle mobilization of adjacent healthy tissue in order to prevent drying, necrosis, and infection is recommended. Saline-soaked gauze is an alternative.
NO PRIMARY CLOSURE OF WAR WOUNDS
When dressing a wound, take care not to plug the wound with packing material, as this prevents proper wound drainage. Leaving the wound open allows the egress of fluids, avoids ischemia, allows for unrestricted edema, and avoids the creation of an anaerobic environment. Lastly, place a non- constricting, nonocclusive dry dressing over the wound.
Wound Management After Initial Surgery
Ideally, the wound should undergo a planned second debridement and irrigation in 24 to 72 hours and subsequent procedures until a clean wound is achieved. It is likely that this serial wound debridement will occur at dif- ferent facilities by different surgeons as the patient traverses the echelons of care. Timing and duration of transport becomes an important planning factor for the surgeon to consider: if a casualty were to depart the surgical facility at the 23-hour point on a 48-hour trip, one should consider a second debridement prior to departure. Between procedures there may be better demarcation of nonviable tissue or the development of local infection.
Early soft-tissue coverage is desirable within 3 to 5 days, when the wound is clean, in order to prevent secondary infection. Delayed closure (3–5 days) requires a clean wound that can be closed without undo tension. This state may be difficult to achieve in war wounds and should not be per- formed if the casualty will not be under direct surgical observation.
Soft-tissue war wounds heal well through secondary intention without sig- nificant loss of function. This is especially is true of simple soft-tissue wounds. Definitive closure with skin grafts and muscle flaps should not be done in the conflict area.
Crush Syndrome
When a victim is crushed or trapped with compression on the extremities for a prolonged time, there is the possibility for the crush syndrome (CS), characterized by ischemia and muscle damage or death (rhabdomyolysis).
In rhabdomyolysis, there is an efflux of potassium, nephrotoxic metabolites, myoglobin, purines, and phosphorous into the circulation, resulting in cardiac and renal dysfunction. Reperfusion injury can cause up to 10 liters of third-space fluid loss per limb, which can precipitate hypovolemic shock.
Acute renal failure (ARF) can result from the combination of nephrotoxic substances from muscle death (myoglobin, uric acid) and hypovolemia, resulting in renal low-flow state. The recognition of crush syndrome relies on proper history and physical exam. Suspect CS in patients in whom there is a history of being trapped (urban operations, mountain operations, earth- quakes, or bombings) for a prolonged period (from hours to days). Note that a clear history is not always available in combat, and the syndrome may appear insidiously in patients that initially appear well. A thorough exam must be done with attention to extremities, trunk, and buttocks. The phys- ical findings depend on the duration of entrapment, treatment rendered, and time since the victim’s release. Extremities initially may appear normal just after extrication. Edema develops rapidly with resuscitation and the extremity becomes swollen, cool, and tense. The patient often may have severe pain out of proportion to exam. Anesthesia and paralysis of the extremities can mimic a spinal cord injury with flaccid paralysis, but there will be normal bowel and bladder function in the CS patient. Again, in the trunk/buttocks, the patient may have severe pain out of proportion to exam in tense compartments.
Laboratory findings in CS are predictable and diagnostic. Creatinine phosphokinase (CK) is elevated with values usually >10000 international units per milliliter. The urine initially may appear concentrated and later change color to a typical reddish-brown color, so called “port-wine” or
“iced-tea” colored urine. The urine output decreases in volume over time. Due to myoglobin, the urine dipstick is positive for blood, but microscopy will not demonstrate red blood cells (RBCs). The urine may be sent to check for a myoglobin, but results take days and should not delay therapy. Hematocrit/hemoglobin (H/H) can vary depending on blood loss, but in isolated crush syndrome H/H is elevated due to hemoconcen- tration from third-spacing fluid losses. With progression of the CS, serum potassium and CK increase further with a worsening metabolic acidosis.
Creatinine and blood urea nitrogen (BUN) will rise as renal failure ensues.
Hyperkalemia is typically the ultimate cause of death from cardiac arrhythmia.
The primary goal of therapy is to prevent acute renal failure in crush syn- drome. Again, the key is to suspect, recognize, and treat rhabdomyolysis early in victims of entrapment. Therapy should be initiated as soon as pos- sible, preferably in the field, while the casualty still is trapped. Ideally, it is 174 D. Jenkins et al.
recommended to establish intravenous (IV) access in a free arm or leg vein.
Avoid potassium- and lactate-containing IV solutions. At least one liter should be given prior to extrication and up to one liter per hour (for short extrication times) to a maximum of six to ten liters per day in prolonged entrapments. As a last resort, amputation may be necessary for rescue of entrapped casualties (ketamine 2 mg/kg IV for anesthesia and use of proximal tourniquet).
Hospital care continues that begun in the field, with attention to the other injuries and electrolyte anomalies, which must be treated while continuing fluid resuscitation to protect renal function. To monitor urine output, a Foley catheter is placed. The goal is to establish and maintain urine output
>100 cubic centimeters per hour until pigments have cleared from the urine.
If necessary, also add sodium bicarbonate to the IV fluid (1 amp/liter D5W) to alkalinize the urine above a pH of 6.5. If unable to monitor urine pH, put one amp in every other IV liter. Additionally, consider the administra- tion of mannitol: 20% solution, one to two grams per kilogram over four hours (up to 200 grams per day) in addition to the IV fluids. Central venous monitoring may be needed with the larger volumes (may exceed 12 liters per day to achieve necessary urine output) of fluid given.
Electrolyte abnormalities to be monitored and addressed include: hyper- kalemia, hyperphosphatemia, hypocalcemia, and hyperuricemia. Acute renal failure requiring dialysis occurs in many of those with severe rhabdomyolysis. Rapid evacuation to an appropriate capable facility is necessary for casualty survival from CS in such cases. The surgical man- agement centers on diagnosis and treatment of Compartment Syndrome (see below)—remember to check torso and buttocks as well. Amputation should be considered in casualties with irreversible muscle necrosis/necrotic extremity.
Compartment Syndrome
Compartment syndrome may occur with an injury to any fascial compart- ment. The fascial defect caused by the injury is not adequate to fully decom- press the compartment, and compartment syndrome still may occur.
Mechanisms of injuries associated with compartment syndrome include any injury resulting in open or closed fractures, penetrating wounds, crush injuries, vascular injuries, and reperfusion following vascular repairs. The early clinical diagnosis of compartment syndrome includes: pain out of pro- portion; pain with passive stretch; and tense, swollen compartments. Late clinical diagnosis includes findings of paresthesia, pulselessness, pallor, and paralysis. In the field setting, the diagnosis of compartment pressures is best made on clinical grounds. Measurement of compartment pressures is not recommended in the combat zone: if the surgeon suspects it, just do the fasciotomy. In fact, prophylactic fasciotomy should be considered in several circumstances outlined below.
The technique of fasciotomy is well described in any surgical text or atlas.
Every war surgeon should familiarize themselves with this anatomy and these techniques prior to deployment. Some key points in fasciotomy of the arm include: open both compartments [anterior flexors (biceps, brachialis) and posterior extensors (triceps)]; the lateral skin incision runs from the deltoid insertion to the lateral epicondyle; attempt to spare the larger cuta- neous nerves; release the intermuscular septum between the anterior and posterior compartments; protect the radial nerve as it passes through the intermuscular septum from the posterior compartment to the anterior com- partment just below the fascia; and release the fascia overlying each com- partment with longitudinal incisions.
For thigh fasciotomies, all three compartments [the anterior (quadriceps), the medial compartment (adductors), and the posterior compartment (hamstrings)] must be released. The key points in technique include: the lateral incision is made from greater trochanter to lateral condyle of the femur; the iliotibial band is incised and the vastus lateralis is reflected off the intermuscular septum bluntly, releasing the anterior compartment; and the intermuscular septum then is incised the length of the incision, releas- ing the posterior compartment. This release of the intermuscular septum should not be made close to the femur, as there are a series of perforating arteries passing through the septum from posterior to anterior near the bone. The medial adductor compartment is released through a separate antero-medial incision.
For calf fasciotomies, all four compartments [lateral compartment (con- taining peroneal brevis and longus), anterior compartment (containing extensor hallucis longus, extensor digitorum communis, tibialis anterior, and peroneus tertius), superficial posterior compartment (containing gastroc- nemius and soleus) and deep posterior compartment (containing the flexor hallucis longus, flexor digitorum longus, and the tibialis posterior)]. A two- incision technique is recommended. These incisions must extend the entire length of the calf in order to release all of the compressing fascia and skin.
The lateral incision is made centered between the fibula and anterior tibial crest. The lateral intermuscular septum and superficial peroneal nerve are identified, and the anterior compartment is released in line with tibialis 176 D. Jenkins et al.
– High-energy wounds
– Intubated, comatose, sedated – Closed head injuries
– Circumferential dressings or casts – Vascular repair
– Prolonged transport – High index of suspicion.
anterior muscle proximally toward the tibial tubercle and distally toward anterior ankle. The lateral compartment then is released through this inci- sion in line with the fibular shaft, proximally toward the fibular head and distally toward the lateral malleolus. A second incision is made medially at least two centimeters medial to the medial-posterior palpable edge of the tibia, not over or near the subcutaneous surface of the tibia in order to prevent exposure of the tibia when the tissues retract. The saphenous vein and nerve are retracted anteriorly and the superficial compartment is released through its length, and then deep posterior compartment over the FDL is released. Then identify the tibialis posterior and release its fascia.
In the foot, there are five compartments to consider: the interosseous compartment (bounded by lateral 1st metatarsal medially, metatarsals and dorsal interosseous fascia dorsally, and the plantar interosseous fascia plan- tarly); the lateral compartment (bounded by 5th metatarsal shaft dorsally, the plantar aponeurosis laterally, and the intermuscular septum medially);
the central compartment (bounded by the intermuscular septum laterally and medially, the interosseous fascia dorsally, and the plantar aponeurosis plantarly); the medial compartment (bounded by the inferior surface of the 1st metatarsal dorsally, the plantar aponeurosis extension medially, and the intermuscular septum laterally); and the calcaneal compartment (contain- ing the quadratus plantae muscle). The foot may be released through a double dorsal incision technique. One incision placed slightly medial to 2nd metatarsal, reaching between 1st and 2nd metatarsals into medial com- partment and between 2nd and 3rd metatarsals into the central compart- ment. A second dorsal incision is made just lateral to 4th metatarsal, reaching between 3rd and 4th metatarsals into central compartment and between 4th and 5th metatarsals into the lateral compartment. In order to spare the dorsal soft tissues, a single-incision medial fasciotomy may be used. A medial approach to the foot is made through the medial compart- ment, reaching across central compartment into interosseous compartments dorsally and lateral compartment releasing all the way across the foot.
Fasciotomy wound management should include the same open-wound guidelines outlined earlier in this chapter. Following the fasciotomy, the fasciotomy wound undergoes primary surgical wound management, remov- ing all devitalized tissue, as discussed above. As with all war wounds, the fasciotomy is left open and covered with sterile dressings.
Shotgun Injuries
Shotguns are used increasingly in war and conflict. Injury is typically inflicted at close range, posing special problems. It is never possible to remove all the shot, and indeed, to do so would result in unacceptable damage to uninjured soft tissues. Wound excision should be carried out on the majority in the manner already described, particularly looking for
indriven wadding and visible plugs of clothing. The retention of lead shot within the wound can result in dangerously high lead concentrations, which should be monitored. With time, lead levels fall as a result of encapsulation of the lead pellets by fibrous tissue.
Summary
Ballistic injury in the military environment poses unique difficulties. The lesson of history is that you cannot take the experience of an urban hospi- tal onto the battlefield. What may be feasible for a single victim managed in peacetime could lead to disaster if transposed to a field hospital in wartime. Military concepts such as wide exposure, debridement, extensive would excision of devitalized soft tissue, delayed primary closure of wounds, and avoidance of prosthetic devices (vascular grafts and internal fixation devices for fractures are examples) were hard learnt on past battlefields and should not be discarded easily into the dustbin (trashcan in the USA) of history.
In conclusion, we list some helpful “Dos and Do Nots”
Do:
– Incise skin generously – Incise fascia widely
– Indentify neurovascular bundles – Excise all devitalized tissue – Remove indriven clothing
– Leave the wound open on completion of surgery – Dress wounds lightly with fluffed up gauze – Record all injuries on field medical cards Do Not:
– Excise too much skin – Practice keyhole surgery
– Repair tendons or nerves at first surgery – Remove attached pieces of bone
– Close the deep fascia – Insert synthetic materials – Pack the wound
– Close the skin
Further Reading
Coupland RM. War Wounds of Limbs—Surgical Management. Oxford:
Butterworth-Heinmann; 1993.
Dufour D, Kroman Jensen S, Owen-Smith M, Salmela J, Stening GF, Zetter Ström B. Surgery for the Victims of War. Geneva: International Committee of the Red Cross: 1998.
178 D. Jenkins et al.
Husum H, Chai SC, Fosse E. War Surgery—Field Manual. Malaysia: Third World Network; 1995.
Husum H, Gilbert M, Wisborg T. Save Lives Save Limbs—Life Support for Victims of Mines, Wars and Accidents. Malaysia: Third World Network; 2000.
Molde Å, Naevin J, Coupland R. Care in the Field for Victims of Weapons of War.
Geneva: International Committee of the Red Cross; 2001.
Ryan JM. Warfare injuries. In: Russell RCG, Williams NS, Bulstrode CJK, eds. Bailey and Love’s Short Practice of Surgery. 23rd ed.. London: Arnold; 2000:281–290.
