It was said...

"The type of projects funded by PTEI provides the initial support required to perform critical pilot studies. The results of these studies are used to strengthen proposals to funding agencies such as the NIH and DARPA. Without the initial funding, there would, in effect, be no preliminary study and thus a follow-up proposal would likely be non-competitive. In short summary, PTEI plays an absolutely critical role in our operations."

Stephen F. Badylak, DVM, PhD, MD
Research Professor, Department of Surgery and Director, Center for Pre-Clinical Tissue Engineering, McGowan Institute for Regenerative Medicine, University of Pittsburgh

Regenerative Medicine Approach to the Treatment of Abdominal Compartment Syndrome in a Dog Model

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Stephen Badylak, DVM, PhD, MD

McGowan Institute for Regenerative Medicine
University of Pittsburgh

Dr. Badylak’s team is working with Walter Reed Army Medical Center, which is the primary military hospital receiving and treating casualties from Operation Iraqi Freedom and Operation Enduring Freedom theaters of war. Walter Reed cares for nearly 4,000 casualties who have been evacuated, including over 1,000 direct battle casualties. This relationship provides our research team with a unique perspective regarding military medical needs and also provides a patient population that can directly benefit from the product of our work.

Unique in the history of trauma has been the experience in the present Middle East war with the vexing problem of the “Open Abdomen”. Walter Reed AMC has received a large, and increasing, number of wounded soldiers requiring in-theater “damage-control laparotomy”, where a forward battlefield surgeon performs emergency opening of the abdominal compartment in order to save the soldier’s life by stopping hemorrhage and then, due to massive fluid resuscitation required at the time and the severe swelling of tissues and organs, is unable to close the fascia of the abdominal compartment. The surgeon therefore places a temporary closure modified from standard plastic sheeting over the abdominal organs and the patient is transferred emergently through Germany and then to Walter Reed, where we have devised a novel method of dealing with this increasing number of wounded soldiers returning with this problem of “Abdominal Compartment Syndrome”.

The Badylak group has developed a modification of the technique of Serial Abdominal Closure, and are presently using a time-sequenced placement of GoreTex ® DualMesh for several weeks to achieve temporary abdominal wall integrity while tightening the closure over time with external clamps⁴⁷.  Several months later the patient is returned to the operating room, the GoreTex® mesh is explanted, and a final polypropylene mesh is implanted to the edges of the rectus sheath.  A primary skin closure over that new mesh is then attempted.

The relative proportion and overall numbers of patients returning to Walter Reed with an Open Abdomen is larger than in any other conflict described, because in the past these types of wounds were typically associated with trauma so severe as to be uniformly lethal. However, with the advances in force protection such as Kevlar helmets and ceramic body armor, the number of troops wounded in combat but surviving their injuries is the best ratio in any recorded American conflict⁴⁸. However, we have not enjoyed the same success in advancing the care of these resultant open abdomen cases. The problems associated with our present methods of care are:

1. The wounds are always colonized with aggressive bacteria, if not overtly infected, and therefore the placement of artificial materials in such a wound is clearly suboptimal, but there is no other reasonable choice at this time in order to gain control of the abdominal compartment;
2. The abdomen cannot simply be left open to heal by second intention, because these soldiers have multiple other injuries (particularly extremities) which require intensive physical therapy and rehabilitation.  An open abdomen without complete structural integrity (i.e. a large ventral hernia in essence) does not allow the soldier to undertake the needed weight lifting and physical exercise rehabilitation needed for full functional return because of the inability to perform valsalva-related maneuvers without full circumferential abdominal wall integrity; and
3. The scar formation that occurs when these abdomens remain open for a long period of time in these cases results in dense adhesional attachments between the abdominal wall fascial edges and the underlying intestines, making it dangerous to re-operate in that area for fear of causing intestinal leaks and fistulas. It is therefore necessary to place the final polypropylene mesh on new uninvolved fascia, which extends the potential area of weakened tissue and increases the risk for infection.

This research and development work is badly needed to devise a safe and effective method of dealing with these devastating, and increasingly occurring, open abdomen situations.  The research addresses the process of regeneration from the battlefield point of injury, so as to prepare the tissues properly for a subsequent successful regeneration-based approach to closure and healing of the open abdomen in soldiers injured on the battlefield.