Continuing Education Activity

The open abdomen is a validated and widely accepted approach to managing surgical and traumatic pathologies. Traumatic open abdomen involves leaving the fascial layer of the abdomen open after a laparotomy for blunt or penetrating trauma with the intention of going back later for definitive repair and closure. This activity describes the indications for a traumatic open abdomen and highlights the role of the interprofessional team in the management of these patients.

Objectives:

• Describe the indications for leaving an abdomen open.
• Summarize the technique for maintaining an open abdomen.
• Review the complications of leaving the abdomen open.
• Explain the importance of prompt, clear communication and collaboration amongst interprofessional team members to improve outcomes for trauma patients with an open abdomen.

Introduction

The open abdomen is a validated and widely accepted approach to managing surgical and traumatic pathologies. Traumatic open abdomen involves leaving the fascial layer of the abdomen open after a laparotomy for blunt or penetrating trauma with the intention of going back later for definitive repair and closure. It can be utilized for damage control with later closure, to facilitate re-exploration or enable additional surgical debridement, or to provide definitive surgery once the patient has stabilized.

Damage control laparotomy (DCL), more specifically, prioritizes the control of hemorrhage and contamination as well as the preservation of physiologic reserves. It is useful in patients who cannot tolerate a prolonged operation. The patient's abdomen is left open with a delay in fascial closure until after visceral injuries can be definitively managed. This is a key benefit of the traumatic open abdomen.

After the initial procedure, the patient is cared for in the intensive care unit (ICU). Patients are assessed on 24 to 48-hour cycles for readiness to return to the operating room. Washouts are performed as needed during this interval. Signs that a patient is ready to return to the operating room include stabilization of vital signs, urine output, urinary bladder pressure, physiological stabilization, and no signs of abdominal infection.

Patients who undergo primary closure during the index hospitalization have shorter intensive care unit (ICU) stays, hospital stays, and quality of life. At least one study found that undergoing more than four operations before primary closure is achieved was significantly associated with failure of the primary fascial closure, while another found that achieving primary closure within eight days of the initial operation was associated with better outcomes.

Additionally, providing enteral nutrition to patients with an open abdomen is another factor that increases the likelihood of successful primary closure. It has also been shown to reduce mortality in these patients compared to those who are kept nil per os (NPO or nothing by mouth). After the shock has resolved, enteral nutrition should be considered in all patients with an open abdomen.[1][2][3][4][5]

Anatomy and Physiology

The traumatic open abdomen involves an incision along the midline of the anterior abdomen. The anatomy of the abdominal wall at this location, from superficial to deep, consists of the following:

• Skin
• Subcutaneous tissue (Camper's fascia)
• Superficial fascia (Scarpa's)
• The linea alba or midline of the rectus sheath (composed of the aponeuroses of the external oblique
• Internal oblique, and transversus abdominis muscles),
• Transversalis fascia.

Below the transversalis fascia lie the preperitoneal space and parietal peritoneum. All of these layers are divided to gain access to the abdominal viscera.

Indications

Some of the most significant indications for leaving an abdomen open after trauma are elevated intra-abdominal pressure, damage control, inability to close, and planned re-exploration. More specifically, these include patients with abdominal compartment syndrome, intra-abdominal hypertension, severe intra-abdominal infection, post-traumatic hemorrhage, peritonitis, bowel edema or ischemia, hypothermia, acidosis, the need for re-exploration after trauma or abdominal sepsis, and high-risk patients in need of a definitive operation that may last longer than 2 hours.[6][7][8]

Contraindications

Contraindications to damage control surgery with open abdomen include those where the patient is hemodynamically stable and able to endure an operation that will last 2 hours or less.

Technique or Treatment

During the interval period between the damage control operation and the definitive operation, various techniques are employed to maintain the open abdomen. These techniques fall under the moniker temporary abdominal closure (TAC) and include negative pressure therapy (NPT), mesh-mediated fascial closure (MMFC), the Wittman patch, fascial traction sutures, sequential tensioning of mesh, Bogota bag, and skin tension.

NPT and MMFC are two commonly utilized forms of TAC. NPT can be implemented using commonly available, cost-effective operating room materials, such as polyethylene, surgical towels, silicone drains, and a plastic polyester adhesive drape. There are also commercially available negative pressure systems. Similarly, MMFC can be performed with mesh materials readily available in most operating rooms, also an extremely cost-effective approach.

Negative pressure dressings have been shown to provide the benefits of stabilizing the abdominal wall, protecting the abdominal viscera, quantifying exudate put out from the wound, and keeping the fascia intact for subsequent closure. However, studies suggest that there is no significant difference in the success of primary delayed closure of the abdomen when either NPT or MMFC are utilized. Rather, the most significant factor in achieving closure is believed to be the utilization of an intermediary technique that applies constant tension to the opposing fascial edges, thus preventing the loss of abdominal domain.

Following TAC, definitive management of the open abdomen is ideally achieved through primary closure. This can involve either early fascial closure or sequential fascial closure. When the abdominal closure is unsuccessful, planned ventral hernia with split-thickness skin graft can be utilized to successfully cover and protect the abdominal viscera. The patient is then returned to the operating room 9 to 12 months later to excise the skin graft and perform herniorrhaphy.[9][10][11]

Complications

Wound complications of an open abdomen are associated with a morbidity rate as high as 25% and have been found to increase significantly if the abdomen is left open for longer than eight days. Complications that can arise from an open abdomen are entero-atmospheric fistula formation, bleeding, infection, multiple organ failure, intra-abdominal abscess, sepsis, loss of bowel function, loss of fluids and protein, loss of abdominal domain, and ventral hernias.

It has been found in recent years that as many as 40% of emergency laparotomy cases are left open. Out of concern for overuse as well as the potential complications of leaving an abdomen open, some institutions have sought ways to streamline the use of the open abdomen in trauma patients. One such institution found that by emphasizing hemorrhage control, the early use of blood products, and minimizing the administration of large amounts of IV fluids in trauma patients undergoing laparotomy, the number who received DCL decreased from 36.6% to 8.8%. This reduction was associated with a decrease in mortality from 21.9% to 12.9% in trauma patients receiving laparotomy over the same period.

Clinical Significance

A traumatic open abdomen is an important tool available to the trauma surgeon for patients whose lives are at risk on the operating room table. When appropriately used, it can provide life-preserving management to critically ill patients until they can be operated on safely and definitively.

The use of DCL has decreased significantly in recent years with the advent of hemostatic or damage control resuscitation. This practice includes the use of permissive hypotension, minimizing the use of crystalloids, and using blood components in ratios similar to whole blood. With the adoption of hemostatic resuscitation has come a dramatic decrease in mortality and the use of open abdomen.

At least one randomized controlled trial is underway to better clarify the clear indications for DCL. Taken collectively, DCL and traumatic open abdomen should be used selectively in patients who are deemed to benefit from them even after hemostatic resuscitative measures have been taken.

Enhancing Healthcare Team Outcomes

The traumatic open abdomen is usually managed by an interprofessional team that includes a general surgeon, trauma surgeon, wound care nurse, radiologist and an infectious disease consultant. The key is to allow the edema to subside and prevent any infection before one undertakes final closure of the abdomen. Many of these patients may require parenteral nutrition and hence a dietary consult is necessary. The outcomes depend on many factors including extent of the injury, comorbidity, patient age, number of organs involved and immune status.