What's new in critical illness and injury science? Management of the open abdomen: Getting it together!

Inspired by the United States Navy, the principle of damage control surgery was first described by Lucas and Ledgerwood.[1] The term was first adopted by Rotondo et al. in 1993. In their study, patients with major vascular injury or two or more visceral injuries had markedly improved survival with damage control compared to definitive laparotomy (77% vs. 11%).[2] In a 2003 review of penetrating abdominal injuries, Johnson et al. compared patients undergoing damage control procedures to patients receiving standard care in the previous decade. They found a significant improvement in mortality for the damage control group.[3] These early results led to the principles of damage control becoming rapidly adopted. By avoiding abdominal compartment syndrome, life-threatening sepsis, and torrential hemorrhage, patient survival dramatically improved. Nevertheless, despite the obvious benefits, questions remain regarding the optimal techniques for the management of the open abdomen.

Various challenges associated with closure of an open abdomen have led to countless techniques, for which there remains no consensus. The earliest concept of temporary abdominal closure was reported by Ogilvie in 1940. In this technique, a Vaseline-soaked cotton cloth, secured with stout salmon gut suture, was used to create a dynamic tension closure. Since that time, the evolution of closure techniques led to three general approaches: passive visceral coverage, negative-pressure therapy, and dynamic tension. Passive visceral coverage with skin only closures and Bogota bags yielded poor fascial closure rates. The introduction of the Wittmann Patch led to significantly improved closure rates by protecting the viscera while preventing lateral retraction of the fascia.[4] Mesh coverage of abdominal viscera with subsequent split-thickness skin grafting has also become a popular approach. As the use of permanent mesh has been widely criticized, and fallen out of favor, absorbable mesh has become the standard of care for this purpose. While some studies suggested that mesh coverage increased the risk of enterocutaneous fistulae, a retrospective review demonstrated that EC fistulae were a result of the burden of injury, rather than the use of mesh.[5]

Negative pressure wound therapy (NPWT) was first described as a means of temporary abdominal coverage by Barker in 1999. This eventually led to the ABTHERA™ system (KCI/Acelity, San Antonio, Texas, USA), a combination of a fenestrated drape and sponges attached to a negative pressure device. The system promotes effective abdominal fluid drainage while preventing “frozen abdomen” and fascial edge retraction. Cheatham et al. conducted a prospective observational study comparing Barker's original temporary VAC dressing to the NPWT system, and found an improvement in days to primary fascial closure (12 vs. 9), 30-day primary fascial closure rate (51% vs. 69%), and 30-day mortality (30% vs. 14%).[6] Miller et al. also reported a primary fascial closure rate of 88% with vacuum-assisted closure.[7] While NPWT has become increasingly popular, newer studies suggest that the therapy is only one component in the effective approach to the open abdomen. A 2016 Italian study evaluating the effectiveness of NPWT in the open abdomen found no difference in fascial closure rates with or without the NPWT (63.5% vs. 69.5%). They concluded that NPWT alone was not sufficient, and should be combined with dynamic fascial closure to be most effective.[8]

The concept of dynamic closure has included several creative modifications to apply traction to the fascia while preventing lateral retraction of the edges. Vacuum-assisted closure with mesh-mediated traction was described by Peterson in 2007, using two polypropylene meshes sutured to the fascial edges, and being tightened and sutured to each other every few days.[9] A Finnish study in 2012 found that this technique increased the odds of delayed primary fascial closure more than 4-fold, compared to nontraction techniques.[10] The newest development is the ABRA Dynamic Tissue System (Southmedic, Ontario, Canada), consisting of skin hooks, adjustable elastomers, and an elastomer retainer, along with a visceral protector to prevent the elastomers from injuring the bowel. The elastomers are inserted perpendicularly through the abdominal wall and sequentially adjusted to increasing grades of tension. An osteopathic maneuver is then performed several times a day to relax the lateral rectus sheath, permitting the edges to come together in a tension-free fashion. The combination of NPWT and dynamic tension yielded the best results, supported by studies performed in Austria and Canada. Mukhi and Minor reported a closure rate of 92% with this combined technique. They proposed applying the ABRA around days 3–5, providing enough time to assess whether the fascia will close with NPWT (ABTHERA™) alone.[11] Another study from Canada evaluated this system over 6 years and reported 83% fascial closure, in a mean duration of 10.4 days. While there are many studies reporting improved outcomes, these are all small retrospective studies, and larger prospective studies are needed to validate the technique. Following the same concept, transabdominal wall traction uses (Johnson & Johnson / Ethicon, Somerville, New Jersey, USA) Ethibond sutures placed through the abdominal wall to allow for sequential closure of the fascia. Dennis et al. studied this technique in both acute and chronic giant ventral hernias and found significant reduction in hernia size, and an average of 8–9 days to closure.[12] Burlew et al. also described their experience with sequential abdominal closure, keeping the fascia under moderate tension, returning to the operating room (OR) every other day, and using #1 polydioxanone suture to partially close the abdomen.[13]

While techniques for closing the open abdomen are critical, it is important to also recognize the effects of resuscitation on this process. It is well known that excessive, crystalloid-based trauma resuscitation has many detrimental effects, including bowel edema, that contribute to the inability to close the abdomen. In 2013, Harvin et al. retrospectively compared resuscitation with hypertonic saline to traditional isotonic resuscitation. By postoperative day 7, 100% of patients with hypertonic resuscitation had fascial closure, compared to only 76% (P = 0.01) in the isotonic group.[14] Similarly, Loftus in 2017 also described improved fascial closure rates with hypertonic saline resuscitation compared to isotonic resuscitation, without any detriments to the electrolyte balance or renal function.[15] This was further described in a protocol-based approach in 2019.[16] These studies underscore the benefits of avoiding excessive crystalloid infusion and using hypertonic saline-based resuscitation to improve the rates of fascial closure.

Direct peritoneal resuscitation is also gaining momentum as a technique for limiting bowel wall edema. A hypertonic, glucose-based solution is infused through a drain into the peritoneal cavity and drained out another. With this technique, Smith et al. reported a 10-fold increase in rates of closure and a 5-fold decrease in intra-abdominal complications.[17] While the techniques for abdominal closure remain essential to the management of the open abdomen, judicious resuscitation practices are an equally important component for the eventual success in abdominal closure.

As damage control surgery and open abdomens have become more prevalent, it is also important to recognize the importance of timely closure of the abdomen. In 2011, Burlew et al. conducted a multi-institutional study exploring the trends in enteric injury management in the open abdomen. In patients with open abdomens closed after day 5, they found a 4-fold increase in enteric leak rate.[18] The Eastern Association for the Surgery of Trauma (EAST) practice management guidelines also emphasize the importance of timely closure. In a review of 79 articles, they found a dramatic increase in complications for abdomens left open beyond day 8 (12% vs. 52%).[19] These data serve as a compelling factor to make vigorous attempts at early closure of the open abdomen.

Recent literature also questions the increasing use of damage control laparotomy (DCL), and highlights some of the risks. In 2019, Harvin et al. published a multicenter prospective study comparing DCL and definitive laparotomy for similar surgical cohort. In 872 patients, there was no difference in the incidence of major abdominal complications, but definitive laparotomy was associated with fewer hospital, ICU, and ventilator days.[20] Further study has been done at the University of Texas-Houston aiming to decrease the number of DCLs performed. Audits and feedback after each case led to a decrease in DCL, from 39% in the control group (2011–2013), to 23% in the Q1 group (2013–2015), and subsequently to 17% after the study period. While a decrease in DCL did not correlate with any difference in mortality or morbidity, there was a decrease in resource utilization.[21] A larger review by Higa et al., however, evaluated 14,534 patients, and observed that, as the use of DCL decreased (36.3% in 2006, to 8.8% in 2008), there was also a decrease in mortality, from 21.9% to 12.9%. Moreover, this was associated with a decrease in costs of $2.2 million.[22] All of these studies drive home the point that DCL is an invaluable technique, but it should be reserved for only those patients who truly need it.

To conclude, DCLs have resulted in unparalleled benefits for trauma patients. The optimal management of these patients and the best practices for abdominal closure remain a challenge. Novel approaches to resuscitation, closure techniques, and optimal timing of abdominal closure show promising results. A clear understanding of fluid resuscitation, the combination of negative pressure therapy and dynamic tension closure, and early closure are keys to successful management of the open abdomen. Judicious patient selection is also central to favorable outcomes.

As our knowledge evolves, we expect to see a significant decrease in the number of DCLs performed, as well as a decrease in the number of “unclosable” abdomens. By reducing the overall number and duration of open abdomens, we also hope to decrease complications such as enterocutaneous fistulae and chronic ventral hernias, which can have life-long consequences for patients. The recent enthusiasm on this subject and the many innovative solutions for resuscitation and closure make for a very exciting time in this realm.