March 2019 - Military Trauma

 

March 2019
EAST Monthly Literature Review


"Keeping You Up-to-Date with Current Literature"
Brought to you by the EAST Manuscript and Literature Review Committee

This issue was prepared by EAST Military Surgery Committee Members Chet Morrison, MD, FACS, FCCS, Christina Riojas, MD, FACS and Uzer Khan, MD, MBBS, FACS.

In This Issue: Military Trauma

Scroll down to see summaries of these articles

Article 1 reviewed by Chet Morrison, MD, FACS
Combat Lifesaver trained first responder application of junctional tourniquets: A prospective randomized crossover trial. Flecha I, Naylor JF, Shauer SG, Curtis RA, Cunningham CW. Military Medical Research. 2018 Sep 13;5(1):31.

Article 2 reviewed by Chet Morrison, MD, FACS
Indications and outcomes of extracorporeal life support in trauma patients. Swol J, Brodie D, Napolitano L, Park PK, Thiagarajan R, Barbaro RP, Lorusso R, McMullan D, Cavarocchi N, Hssain AA, Rycus P, Zonies D; Extracorporeal Life Support Organization (ELSO). J Trauma Acute Care Surg. 2018 Jun;84(6):831-837.

Article 3 reviewed by Christina Riojas, MD, FACS
Tourniquet use is not associated with limb loss following military lower extremity arterial trauma. Kauvar DS, Miller D, Walters TJ. J Trauma Acute Care Surg. 2018 Sep;85(3):495-499.

Article 4 reviewed by Christina Riojas, MD, FACS
Assessing Risk and Related Complications after Reversal of Combat-Associated Ostomies. Johnston LR, Bradley MJ, Rodriguez CJ, McNally MP, Elster EA, Duncan JE. J Am Coll Surg. 2018 Sep;227(3):367-373.

Article 5 reviewed by Uzer Khan, MD, MBBS, FACS
The use of whole blood in US military operations in Iraq, Syria, and Afghanistan since the introduction of low-titer Type O whole blood: feasibility, acceptability, challenges. . Vanderspurt CK, Spinella PC, Cap AP, Hill R, Matthews SA, Corley JB, Gurney JM. Transfusion. 2019 Mar; 59(3):965-970.

Article 6 reviewed by Uzer Khan, MD, MBBS, FACS
Predictors and Timing of Amputations in Military Lower Extremity Trauma With Arterial Injury. Thomas SB, Schechtman DW, Walters TJ, Kauvar DS. J Trauma Acute Care Surg. 2019 Jul;87(1S Suppl 1):S172-S177.

Article 1
Combat Lifesaver trained first responder application of junctional tourniquets: A prospective randomized crossover trial. Flecha I, Naylor JF, Shauer SG, Curtis RA, Cunningham CW. Military Medical Research. 2018 Sep 13;5(1):31.

Most surgeons, particularly military surgeons are familiar with the use of extremity tourniquets, which if used properly are a straightforward way of controlling extremity hemorrhage prior to definitive operative repair. However, hemorrhage originating from the groin or axilla is a more difficult problem, as standard tourniquets will not control these areas; indeed, junctional hemorrhage surpassed extremity hemorrhage as the leading cause of preventable death after the resurgence of limb tourniquets during the recent conflicts in Afghanistan and Iraq and has been very effectively dramatized in a very popular war movie. TO meet this need, Junctional tourniquets (JTQs) were developed in response to this injury pattern. These devices are new and much less straightforward in their application and have only recently been approved. Published data for JTQ efficacy are limited and do not incorporate nonmedical, military first responders; their use in a civilian population remains unclear.

In this study by Manley and colleagues, two JTQs were compared: the SAM® Medical Junctional Tourniquet (SJT) and Junctional Emergency Treatment Tool (JETT™). Investigators simple randomized combat life support (CLS) and combat medics to SJT or JETT for their first JTQ application on mannequins with penetrating inguinal injuries. Then, participants immediately placed the other JTQ on another casualty with the same injury. The primary outcome measured was time of successful application. Success was defined as proper JTQ placement and a pressure reading of at least 180 mmHg. Outcomes were then compared between CLS and combat medics. A total of 227 personnel (133 CLS and 94 combat medics) at Fort Hood, Texas, USA were studied. Twenty-eight percent (38 of 133) of CLS and 40% (38 of 94) of combat medics placed both JTQs successfully, for a total of 152 applications (76 SJTs and 76 JETTs). There was a significant difference between applications of the JETT between the CLS and combat medics (92.0 ± 37.7 s versus 70.5 ± 20.5 s, P = 0.004). No other subgroup analyses, whether by device or user, demonstrated a significant difference in application time. Both groups preferred the SJT over the JETT. CLS disagreed with combat medics that the JETT could be easily applied by one person. Thus, overall, success rates for both the SJT and JETT were low. The investigators concluded that improved training is needed to increase successful application of junctional tourniquets before widespread implementation. Combat lifesavers and combat medics prefer the SJT over the JETT.

The study has several important strengths that are particularly relevant to military surgeons who are interested in these devices: it took place during realistic combat casualty simulations that were conducted in a major military training center; the participants were soldiers with differing levels of training; and the participants were highly motivated to complete both tasks with the investigators getting objective evidence of successful tourniquet placement, rather then merely heuristic inspection of the tourniquets. No simulation can be totally the same as a real battlefield however, and thus this is more of a proof of concept rather than a truly generalizable demonstration of the effectiveness of the device. As the investigators did not provide pictures of the tested devices, I reproduce them here:

This is the SJT device, which also provides pelvic compression:


There is also a neat YouTube video of the device, with appropriate military music:
 
https://www.youtube.com/watch?v=8o7myD-u8KM

It is unclear to this reviewer whether these devices will be the last word in junctional tourniquets that are actually used in a military combat or civilian trauma system, but it is very clear that there is a lot of work on this very real combat problem, with the potential for lives saved and hospital stays shortened.

Article 2
Indications and outcomes of extracorporeal life support in trauma patients. Swol J, Brodie D, Napolitano L, Park PK, Thiagarajan R, Barbaro RP, Lorusso R, McMullan D, Cavarocchi N, Hssain AA, Rycus P, Zonies D; Extracorporeal Life Support Organization (ELSO). J Trauma Acute Care Surg. 2018 Jun;84(6):831-837.

This article was chosen from the Memphis group, who have previously given us a simplified algorithm, applicable to military surgeons, of how to handle destructive colon injuries. Although we have evolved from mandatory ostomy for all colon injuries, surgeons will frequently place an ostomy for destructive colon injuries requiring resection; according to their algorithm, this should be done if there is more than six units of blood products required pre- or intra-op (which would presumably include all patients undergoing a massive transfusion protocol). But what sort of ostomy should one place? Conflicting evidence exists regarding the definitive management of destructive colon injuries. Although diversion with an end ostomy can theoretically decrease initial complications, it mandates a more extensive reversal procedure. Conversely, anastomosis with proximal loop ostomy diversion, while simplifying the reversal, increases the number of suture lines in the peritoneum and potential initial morbidity. Thus, the authors using their own extensive database, evaluated the impact of diversion technique on morbidity and mortality in patients with destructive colon injuries.

Using patients from 1996 to 2016, they measured outcomes, including ostomy complications (obstruction, ischemia, readmission) and reversal complications (obstruction, abscess, suture line failure, fascial dehiscence), comparing patients managed with a loop versus end colostomy. A total of 115 patients were identified: 80 with end colostomy and 35 with loop ostomy. Ostomy complications occurred in 22 patients (19%), and 11 patients (10%) suffered reversal complications. There was no difference in ostomy-related (2.9% vs. 3.8%, p = 0.99) mortality. They then analyzed a subset a patient who suffered a planned ventral hernia (PVH) and compared them to patients without a planned ventral hernia (PVH). There was no difference in ostomy complications between patients managed with a loop versus end colostomy (12% vs. 18%, p = 0.72). However, patients managed with a loop ostomy had a shorter reversal operative time (95 vs. 245 minutes, p = 0.002) and reversal length of stay (6 vs. 10, p = 0.03) with fewer reversal complications (0% vs. 36%, p = 0.02). Thus, they also had shorter length of stay and reduced hospital charges. But, for patients with a PVH, there was no difference in outcomes between patients managed with a loop versus end colostomy.

The study provided good evidence that what is intuitive to surgeons bears out in practice: It is easier to reverse a loop than end ostomy, and this is something that should be considered, if technically feasible (which is not always the case). Their single institution numbers are good. Of course, as in any retrospective study, there is little guidance as to when to do each technique going forward, as there are likely confounders, technical and physiologic that made surgeons choose one over the other. Also, this reviewer hopes that fewer and fewer patients will require planned ventral hernias going forward, given improvements in abdominal dressings and closure techniques. Keep in mind that patients with rectal injuries were excluded from the study, so these results may not be applicable to them. Finally, I refer readers to the EAST guideline on colon injuries, which state:

1. Patients with penetrating intraperitoneal colon wounds which are destructive (involvement of > 50% of the bowel wall or devascularization of a bowel segment) can undergo resection and primary anastomosis if they are:

Hemodynamically stable without evidence of shock (sustained pre- or intraoperative hypotension as  defined by SBP < 90 mm Hg),
Have no significant underlying disease,
Have minimal associated injuries (PATI < 25, ISS < 25, Flint grade < 11),
Have no peritonitis.

2. Patients with shock, underlying disease, significant associated injuries, or peritonitis should have destructive colon wounds managed by resection and colostomy.  
Perhaps this study will help further refine these guidelines.

Article 3
Tourniquet use is not associated with limb loss following military lower extremity arterial trauma. Kauvar DS, Miller D, Walters TJ. J Trauma Acute Care Surg. 2018 Sep;85(3):495-499.

Most studies of tourniquet use for military arterial injury focus on hemorrhagic shock and mortality. Fewer studies report follow-up regarding limb loss and function, and they are shorter follow-ups. This was a retrospective cohort study of injuries sustained in combat from 2004-2012. Injuries to common femoral, superficial femoral, deep femoral, popliteal or tibial arteries were identified and outcomes were compared between limbs with tourniquets (TK) and limbs without tourniquets (NTK). 455 injured limbs were identified, with approximately half receiving tourniquets (56% TK). Tourniquet use was more frequent as the years passed. Injuries were most commonly blast-related, followed by GSW. There was no difference in delayed amputation, sensory loss, muscle contracture or severe edema, although wound infection and foot drop were more frequent in TK limbs. TK limbs had greater limb injury severity and had fasciotomies performed more frequently. Above knee amputation was twice as likely in the TK group, but this was not statistically significant. There was no difference in mortality or deep venous thrombosis, although there was a higher risk of pulmonary embolism in TK. In TK limbs, tourniquet time ≥60 minutes was associated with higher incidence of rhabdomyolysis, but not increased risk of amputation or vascular reconstruction complication.
 
One of the concerns about tourniquet use is the risk of ischemia and damage to underlying structures possibly leading to limb loss. This study lends further support for the use of tourniquets by reporting no increase in the risk of decreased sensory function, muscle contracture or edema following use of tourniquet for lower extremity vascular injury, even when used on more severely injured limbs. Even prolonged tourniquet use greater than an hour was not associated with amputation. This adds to the literature in support of tourniquets by reinforcing the minimal risk of complications especially compared to the immense benefit of preventing life threatening hemorrhage.
 
Level 3 recommendation from 2012 EAST guideline - In cases of hemorrhage from penetrating lower extremity trauma in which manual compression is unsuccessful, tourniquets may be used as a temporary adjunct for hemorrhage control until definitive repair.

Article 4
Assessing Risk and Related Complications after Reversal of Combat-Associated Ostomies. Johnston LR, Bradley MJ, Rodriguez CJ, McNally MP, Elster EA, Duncan JE. J Am Coll Surg. 2018 Sep;227(3):367-373.

The management of colon injuries has shifted from primary repair to mandatory fecal diversion, which was intended to decrease mortality. Primary repair is now standard practice for the majority of civilian colorectal injuries following reports of decreased morbidity and mortality without diversion. In contrast, combat-related colorectal injuries are still frequently managed with fecal diversion, with a high rate of restoration of GI continuity. However, outcomes from ostomy reversal in this population have not been studied. This was a retrospective cohort study of soldiers in Afghanistan and Iraq who underwent ostomy reversal between 2003 and 2015. 99 patients were identified- the majority had end colostomies (68%), and the remainder had loop colostomies or end ileostomies. Indications for diversion were equally split between colon, rectal and perineal injury. Injuries were mostly related to explosions. There was a 40% incidence of complications (most frequently superficial SSI), but no mortality at 30 days. There was one anastomotic leak, one small bowel obstruction and one deep venous thrombosis/ pulmonary embolism; other complications included need for blood transfusion, intraabdominal abscess, incisional hernia, return to OR and Clostridium difficile infection. Risk factors for complications included perineal wound, end colostomy, longer interval between ostomy creation and reversal, and longer hospital stay; injury severity score, need for open abdomen or damage control surgery and perioperative vitals were not associated with increased incidence of complications.
 
Combat colon injuries are not the same entity as civilian traumatic colon injuries. The distinct pattern of injuries known as dismounted complex blast injury, which was responsible for the injuries in 1/3 of the patients evaluated in this study, involves severe destructive injury to lower extremities combined with abdominal, pelvic or urogenital injury. Because of the unique nature of the injury pattern, colostomy remains an important component of our management algorithm. Injury prevention is important, but following injury, our goal is to minimize further complications. One of the risk factors that we can address is minimizing the interval between ostomy creation and reversal.
 
Level 2 recommendations from 1999 EAST guidelines-
Patients with shock, underlying disease, significant associated injuries, or peritonitis should have destructive colon wounds managed by resection and colostomy. 

Colostomies performed following colon and rectal trauma can be closed within two weeks if contrast enema is performed to confirm distal colon healing. This recommendation pertains to patients who do not have non-healing bowel injury, unresolved wound sepsis, or are unstable.
/education/practice-management-guidelines/colon-injuries-penetrating

Article 5
The use of whole blood in US military operations in Iraq, Syria, and Afghanistan since the introduction of low-titer Type O whole blood: feasibility, acceptability, challenges. . Vanderspurt CK, Spinella PC, Cap AP, Hill R, Matthews SA, Corley JB, Gurney JM. Transfusion. 2019 Mar; 59(3):965-970.

The use of whole blood in the military and austere environment has been in place since World War I and is associated with improved mortality when compared with RBCs and plasma alone. Nevertheless, the risk of ABO incompatibility (most often through user error in low-resource settings) has resulted in the development of low-titer type O whole blood (LTOWB). In addition, to minimizing the risk of ABO incompatibility, LTOWB allows for more rapid initiation of blood transfusion (no cross-match to wait for).  In a variety of ways, LTOWB is superior to component therapy from a logistical perspective as well.  With the shift in emphasis from the walking blood bank (warm fresh whole blood) to cold-stored LTOWB, Vanderspurt et al conducted their retrospective review of LTOWB use through the Theater Medical Data Stores database and hypothesized that demand would increase over the past two years of its use.

What the authors found was that there was an overall increase in LTOWB use compared to all types of transfusions from 0.5% to 4% (a 700% increase). The logistical benefits (no freezers required, full components) suggest a good fit for the resource-poor, far-forward conditions.  This finding can help inform future considerations related to supply in these far-forward areas as well as selecting the use of preservatives to maximum shelf-life. Nevertheless, the study is retrospective in nature and suffers the caveats of all studies of this type. Furthermore, the Theater Medical Data Store is an administrative database and did not include clinical factors that may have affected the specific findings or clinician transfusion preferences. In summary, LTOWB is here to stay - its use is increasing in the civilian as well as the military setting and its evident advantages should be an easy springboard for performance improvement interventions in all clinical settings.

Article 6
Predictors and Timing of Amputations in Military Lower Extremity Trauma With Arterial Injury. Thomas SB, Schechtman DW, Walters TJ, Kauvar DS. J Trauma Acute Care Surg. 2019 Jul;87(1S Suppl 1):S172-S177.

Much of the quality improvement work related to combat trauma resulting in extremity amputation is predicated on the assumption that time from injury is the paramount categorization in predicting risk.  However, an overlooked category that Thomas et al wish to discuss in their published work is amputations that are conducted before or after evacuation from combat theater (i.e. at lower or higher resource locations). The goal of their study was to identify any distinction between early amputation and failure of limb salvage following evacuation to guide future resource allocation for limb salvage.

A retrospective database review (of the Fasciotomy and Vascular Injury Outcomes (FaVIO) database) was conducted and patients with extremity vascular injuries identified. Limbs were included if they underwent one limb salvage attempt and underwent a vascular intervention of any kind including shunting or ligation.  Mechanisms, ISS and MESS scores were also reviewed. 

Of 455 casualties, 103 amputations were performed for an overall rate of 23%. 20% were performed prior to evacuation while the rest were after overseas evacuation. This suggests that damage control interventions are, in-general, successful and lead to limbs that are viable until casualties reached comprehensive care facilities. As expected, greater overall casualty and limb injury severity were associated with amputation - this finding, however, remained true after initial salvage was deemed successful. Further, arterial injury at the popliteal level was most commonly associated with amputation (28%).  Of note, the MESS score (otherwise called into question in civilian populations) was found to be predictive of both early and late amputations in the military population. The take-home point from this study is that limb outcomes affecting function (loss of sensation, contractures, loss of motor function) affect long-term and post-discharge limb salvage decisions. This, coupled with the fact that in-theater limb salvage is generally successful, suggests improvements in limb salvage rates are most likely to be impacted through increased emphasis on post-evacuation care and rehabilitation.