John M. McClellan

RESUSCITATIVE ENDOVASCULAR BALLOON OCCLUSION OF THE AORTA (REBOA) FOR MAJOR ABDOMINAL VENOUS INJURY IN A PORCINE HEMORRHAGIC SHOCK MODEL.

BACKGROUND Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a rescue maneuver for unstable patients with noncompressible hemorrhage below the diaphragm. The efficacy of REBOA in the setting a major abdominal venous injury is unknown. Our objective was to examine the use of REBOA in a large animal model of major abdominal venous injury and characterize any impact on the hemodynamics, rate and volume of hemorrhage, and survival. METHODS Ten swine (35–55 kg) underwent a controlled and validated hemorrhage and ischemia/reperfusion injury protocol to produce shock physiology. Animals were randomly assigned to a control arm (N = 5) or a treatment (REBOA) arm (N = 5). An injury was then created in the common iliac vein. Bleeding was allowed for 60 seconds and the balloon was then inflated in the REBOA arm. Hemodynamics were recorded for 45 minutes or until death. Blood loss was verified post-mortem and bleeding rate calculated. RESULTS All animals demonstrated shock physiology at the time of randomization. There were no differences between control versus REBOA animals in baseline mean arterial pressure (42 vs. 50), pH (7.29 vs. 7.26), lactate (6.19 vs. 6.26), or INR (1.2 vs. 1.3, all p = NS). REBOA animals demonstrated immediate improvements in mean arterial pressure (50.6 vs. 97.2, p = 0.04). The mean survival time was 4.1 minutes for controls (100% died) versus 40.1 minutes for REBOA (p < 0.01). There was no difference in total blood loss (mean 630 mL for both). The rate of bleeding was significantly lower in the REBOA animals (control 197 mL/min vs. REBOA 14 mL/min, p = 0.02). CONCLUSION In the setting of an abdominal venous injury, REBOA improved hemodynamics and lengthened survival time. Blood loss was similar between groups but the rate of bleeding was markedly decreased with REBOA. REBOA appears effective for central venous injuries and provides a sustained period of stabilization and window for surgical intervention.

Smartphone-based mobile thermal imaging technology to assess limb perfusion and tourniquet effectiveness under normal and blackout conditions

BACKGROUND Over the past decade, there has been a resurgence of tourniquet use in civilian and military settings. Several key challenges include assessment of limb perfusion and adequacy of tourniquet placement, particularly in the austere or prehospital environments. We investigated the utility of thermal imaging to assess adequacy of tourniquet placement. METHODS The FLIR ONE smartphone-based thermal imager was utilized. Ten swine underwent tourniquet placement with no associated hemorrhage (n = 5) or with 40% hemorrhage (n = 5). Experiment 1 simulated proper tourniquet application, experiment 2 had one of two tourniquets inadequately tightened, and experiment 3 had one of two tourniquets inadequately tightened while simulating blackout-combat conditions. Static images were taken at multiple time points up to 30 minutes. Thermal images were then presented to blinded evaluators who assessed adequacy of tourniquet placement. RESULTS The mean core temperature was 38.3 °C in non-hemorrhaged animals versus 38.2 °C in hemorrhaged animals. Hemorrhaged animals were more hypotensive (p = 0.001), anemic (p < 0.001), vasodilated (p = 0.008), and had a lower cardiac output (p = 0.007) compared to non-hemorrhaged animals. The thermal imaging temperature reading decreased significantly after proper tourniquet placement in all animals, with no difference between hemorrhaged and non-hemorrhaged groups at 30 minutes (p = 0.23). Qualitative thermal image analysis showed clearly visible perfusion differences in all animals between baseline, adequate tourniquet, and inadequate tourniquet in both hemorrhaged and non-hemorrhaged groups. Ninety-eight percent of blinded evaluators (n = 62) correctly identified adequate and inadequate tourniquet placement at 5 minutes. Images in blackout conditions showed no adverse impact on thermal measurements or in the ability to accurately characterize perfusion and tourniquet adequacy. CONCLUSIONS A simple handheld smartphone-based forward looking infrared radiometry device demonstrated a high degree of accuracy, reliability, and ease of use for assessing limb perfusion. Forward looking infrared radiometry also allowed for rapid and reliable identification of adequate tourniquet placement that was not affected by major hemorrhage or blackout conditions.

Hemopericardium after laparoscopic perihiatal procedures: high index of suspicion facilitates early diagnosis and successful nonoperative management.

Hemopericardium after laparoscopic perihiatal procedures: high index of suspicion facilitates early diagnosis and successful nonoperative management John M. McClellan, M.D.*, Daniel Nelson, D.O., Matthew Martin, M.D., F.A.C.S. Madigan Army Medical Center, Joint Base Lewis McCord, Tacoma, Washington Brian Allgood Army Community Hospital, Seoul, South Korea Received November 10, 2015; accepted December 11, 2015

Three- versus four-factor prothrombin complex concentrates for “factor-based” resuscitation in a porcine hemorrhagic shock model

BACKGROUND Bleeding is a leading cause of preventable death after severe injury. Prothrombin complex concentrates (PCC) treat inborn coagulation disorders and reverse oral anticoagulants, but are proposed for use in “factor-based” resuscitation strategies. Few studies exist for this indication in acidosis, or that compare 3-factor PCC (3PCC) versus 4-factor PCC (4PCC) products. We aimed to assess and compare their safety and efficacy in a porcine model of severe hemorrhagic shock and coagulopathy. METHODS Twenty-five adult Yorkshire swine underwent 35% volume hemorrhage, ischemia-reperfusion injury, and protocolized crystalloid resuscitation. Seventeen animals were randomized at 4 hours after model creation to receive a 45-IU/kg dose of either 3PCC or 4PCC. An additional eight animals received autologous plasma transfusion before 4PCC to better characterize response to PCC. Individual factor levels were drawn at 4 hours and 6 hours. RESULTS The model created significant acidosis with mean pH of 7.21 and lactate of 9.6 mmol/L. After PCC, 66.7% of 3PCC animals and 25% of 4PCC animals (regardless of plasma administration) developed consumptive coagulopathy. The animals that developed consumptive coagulopathy had manifested the “lethal triad” with lower temperatures (36.3°C vs. 37.8°C), increased acidosis (pH, 7.14 vs. 7.27; base excess, −12.1 vs. –6.5 mEq/L), and worse coagulopathy (prothrombin time, 17.1 vs. 14.6 seconds; fibrinogen, 87.9 vs. 124.1 mg/dL) (all p < 0.05). In the absence of a consumptive coagulopathy, 3PCC and 4PCC improved individual clotting factors with transient improvement of prothrombin time, but there was significant depletion of fibrinogen and platelets with no lasting improvement of coagulopathy. CONCLUSION PCC failed to correct coagulopathy and was associated with fibrinogen and platelet depletion. Of greater concern, PCC administration resulted in consumptive coagulopathy in the more severely ill animals. The incidence of consumptive coagulopathy was markedly increased with 3PCC versus 4PCC, and these products should be used with caution in this setting.

Bariatric surgery patient perceptions and willingness to consent to resident participation

BACKGROUND Many bariatric surgery programs are located at teaching hospitals, where they are integral to the training of surgical residents. OBJECTIVES The purpose of this study was to examine preexisting bariatric patient perceptions and willingness to allow resident participation in their surgery. SETTING Madigan Army Medical Center, Tacoma, Washington, USA. METHODS Anonymous questionnaire was given to bariatric patients at their preoperative appointment at an academic teaching hospital. The survey captured demographic characteristics, overall opinions of teaching programs, and willingness to consent to various scenarios of trainee participation. Univariate and multivariate analyses were performed. RESULTS One hundred eight patients (93% female) completed the questionnaire. Most patients (92.4%) expressed overall support for their procedure being performed at a teaching hospital. When presented with several realistic scenarios, most patients would consent to having a staff surgeon operate and residents/students observe (86%). However, only 56% of patients would consent to a resident assisting staff during a procedure and barely 14% of patients would consent to staff surgeon observing. An independent factor associated with increased willingness to consent to resident participation included patients whose first choice would be to undergo surgery at a teaching hospital (P< .05). CONCLUSION Overall, patients expressed support for the teaching hospital model and resident education and participation. However, their willingness to consent to specific realistic scenarios involving various levels of resident participation in their surgery ranged widely. Although patients prefer detailed informed consent, it has the potential to negatively affect resident participation and training.

Solid pseudopapillary tumour (Frantz’s tumour) of the pancreas in childhood: successful management of late liver metastases with sunitinib and chemoembolisation

The patient is a girl aged 17 years who originally presented at age 11 years with a solid pseudopapillary tumour (SPT) in the head of the pancreas treated by an R0 pylorus-preserving Whipple procedure. The patient underwent surveillance CT every 3 months for the first year followed by MRI every 6 months. She was noted to have a new liver lesion in Couinaud segment VI highly suspicious for metastasis at 30 months. Liver wedge biopsy confirmed metastatic SPT. Two months later two new lesions were noted in Couinaud segment VII. The family preferred medical management to surgery resulting in a treatment combination of the tyrosine kinase inhibitor sunitinib and hepatic artery embolisation. The patient developed a hepatic abscess following embolisation but recovered with antibiotics. The patient has subsequently been followed with serial MRIs every 3 months, and 20 months following chemoembolisation, she has no evidence of recurrence of the metastases.