Application of pie-crusting technique to facilitate closure of open abdomen after decompressive laparotomy

Abstract

We present the case of a 23-year-old man who developed abdominal compartment syndrome secondary to severe pancreatitis and required decompressive laparotomy and pancreatic necrosectomy. Despite application of a temporary abdominal closure system (ABThera Open Abdomen Negative Pressure Therapy), extensive retroperitoneal oedema and inflammation continued to contribute to loss of domain and prevented primary closure of the skin and fascia. The usual course of action would have involved reapplication of ABThera system until primary closure could be achieved or sufficient granulation tissue permitted split-thickness skin grafting. Though a safe option for abdominal closure, application of a skin graft would delay return to baseline functional status and require eventual graft excision with abdominal wall reconstruction for this active labourer. Thus, we achieved primary closure of the skin through the novel application of abdominal wall ‘pie-crusting’, or tension-releasing multiple skin incisions, technique.

Background

Wound healing is a fundamental component of surgical practice. While primary closure is the ideal option for surgical incisions under minimal tension, patients with complex defects or segmental tissue loss require careful consideration to balance successful wound healing with cosmetic and functional outcomes. Recently, the increasing prevalence of damage control approaches within emergency general surgery has created new wound categories. Acute care surgeons commonly encounter large open wounds as a result of surgical tissue loss, such as debridement of necrotising soft tissue infection, or due to significant oedema in the underlying tissue compartments leading to undue tension at the skin edges, such as in compartment syndrome of the leg or complex orthopaedic procedures. Large surgical wounds are also encountered in the abdomen due to the loss of anatomical domain following serial exploration or debridement, resulting in the formation of granulation tissue in the wound bed.¹

Damage control laparotomy is a viable and life-saving option for the management of abdominal compartment syndrome, intra-abdominal sepsis and traumatic injury. However, the resultant open abdomen is not without significant morbidity and mortality.² Delay to achieve coverage of the abdominal content is associated with high risk of enteric leak and enteroatmospheric fistula formation.³ Advances in wound management have offered some alternative options to achieve wound closure.⁴ However, the optimal method of abdominal closure is still not clear.⁵ Skin grafting is considered a viable option to provide coverage of wounds with large defects after adequate granulation tissue formation.^{6 7} The cutaneous coverage of the wounds with split thickness skin grafting provides an epithelial layer to protect from fluid loss and promote wound contraction. However, the recovery course is somewhat lengthy and requires frequent hospital or office visits. There is also additional morbidity associated with the graft donor site including significant pain, discomfort and potential for infection or other wound complications.^8–10 While commercial wound dressings and negative pressure wound therapy have been ubiquitously adopted to address similar concerns, they are associated with prohibitively high costs of care that limit availability for patients including the uninsured. We, therefore, present the application of pie-crusting technique or tension-releasing multiple skin incisions as an option to facilitate early tension-free primary closure.

Case presentation

We present the case of a 23-year-old man who presented to our institution with severe alcoholic pancreatitis complicated by the development of abdominal compartment syndrome. On presentation, he had signs of severe inflammatory response with tachycardia (122/min), tachypnea (24/min), lactatemia (3 mEq/dL), leucocytosis (White blood cells (WBC) of 18.9 x 10⁹/L), haemoconcentration (haemoglobin: 18.2 g/dL), acute kidney injury (creatinine: 4.95 mg/dL), hyponatremia (120 mEq/dL) and elevated lipase level (1063 IU/L). CT of the abdomen confirmed the diagnosis of acute pancreatitis. Early in his course he developed multiorgan failure, manifested by acute kidney injury and acute respiratory distress syndrome requiring intubation and mechanical ventilation support. Due to significant abdominal distension and rigidity, as well as difficulty maintaining adequate ventilation, intra-abdominal pressure was assessed. His bladder pressure was elevated to 65 cmH₂O, consistent with the diagnosis of abdominal compartment syndrome. At the time, the patient also required increasing ventilator support with a driving pressure of 20 cmH₂O, resulting in a tidal volume of only 300 mL.

Thus, he underwent decompressive laparotomy with temporary abdominal closure, followed by a second-look laparotomy 4 days later. During the second exploration, significant pancreatic necrosis was identified. Therefore, a debridement of the pancreatic necrosis was required, and pancreatic necrosectomy was performed. The laparotomy incision was left open due to worsening intraoperative coagulopathy requiring hemostatic packing of the lesser sac. Temporary abdominal wall closure was achieved using the ABThera Open Abdomen Negative Pressure Therapy system. On return to the operating room for removal of packs and exploration of the abdomen, the patient continued to demonstrate significant inflammation and oedema in the retroperitoneum that resulted in a loss of abdominal wall domain with approximately 20 cm between skin edges, thus preventing primary closure of the laparotomy incision or underlying fascia.

Treatment

Under typical circumstances, we would have performed a reapplication of the ABThera system over an absorbable mesh (Vicryl) that bridges the fascial edges, followed by frequent dressing changes until either primary closure could be achieved or until the formation of sufficient granulation over the abdominal content allowed temporary coverage with a split thickness skin graft (STSG). Several months later, the patient would undergo planned return to the operating room for STSG excision and abdominal wall reconstruction with possible component separation as needed to create an apposition of the musculofascial planes.

In the case of our patient, however, we achieved primary skin closure through the novel application of abdominal wall pie-crusting, which was previously been described in the literature as tension-releasing multiple skin incisions. The fascial edges were bridged with a Vicryl absorbable mesh to help contain the bowel loops. Beginning approximately 2 cm away from the edges of our midline incision, a series of 1 cm, full-thickness dermal incisions were oriented parallel to our original laparotomy on either side of the existing incision. In a similar fashion, additional series of tension-releasing incisions were placed moving laterally across the abdominal wall until the remaining tension on the laparotomy was attenuated to a permissible degree for primary skin closure (figure 1). The resulting wounds from pie-crusting were covered with Adaptic non-adherent dressings and were changed daily. The patient’s medical management continued postoperatively without wound complications.

Figure 1.

Application and healing of pie-crusting approach to the open abdominal wound in our patient. (A) At 1 week postoperatively, (B) at 1 months postoperatively, (C) at at 12 months postoperatively.

Outcome and follow-up

We evaluated the patient during outpatient follow-up visits for up to 12 months from original surgery with complete healing of the midline laparotomy and pie-crusting incisions without notable hypertrophic scar or keloid development. There was mild discolouration of the pie-crusting incision sites; however, the skin was soft to palpation (figure 1). As we were unable to close the fascia secondary to his intraabdominal volume expansion, he continued to exhibit a large incisional hernia throughout his postoperative follow-up. Despite the laborious nature of his daily job, he declined to proceed with surgical repair of the hernia and did not have specific concerns related to his fascial defect.

Discussion

‘Pie-crusting’, or tension-release skin fenestration technique has been described and used sporadically. It is proposed as an alternative technique to primarily close wounds that remain under tension due to oedema or increased pressure compartments. It was first reported in the early 1990s as an option to address skin coverage of lower extremity orthopaedic traumatic injuries.¹¹ In the report by Robinson et al, 15 patients underwent lower extremity pie-crusting for significant oedema after distal arterial bypass and there were no wound complications.¹² Since its early description, the technique became of interest in orthopaedic surgery practice.^{13 14} Technique and outcomes were recently shared in the medical twitter community.¹⁵ However, it has been rarely used by acute care surgeons and has never reported in wounds outside of the extremities.

As previously described, the technique involves making several rows of longitudinal, full-thickness dermal incisions parallel to the long axis on each side of the wound with a fine surgical blade. The small incisions are about 5 mm to 10 mm in length and may be placed 5 mm apart, depending on the quality and elasticity of the native tissue. The exact measurement can vary depending on the anatomic location of the wound and the distance between the skin edges that the surgeon wishes to approximate. The wounds in adjacent lines are placed in a staggering fashion, and each row provides approximately 5 mm of additional elongation when attempting approximation. In this way, when the skin edges of the primary incision are approximated, the skin on either side of the wound appears to stretch out as subcutaneous tissue is visualised beneath the ‘native dermal mesh’. From a biomechanics perspective, this technique distributes the force that would have previously been applied over the small area of the original wound edge across the area of the entire abdominal wall, thus decreasing local pressure at the site of primary incision.¹⁶ The edges of the wound may then be approximated, and the skin closed primarily with either staples or the surgeon’s suture of choice. In our experience, simple interrupted sutures or vertical mattress sutures suffice (figure 2). The surgeon should confirm that the stretched skin on either side of the wound continues to be well perfused, as evident by colour and palpation to evaluate over stretching of the skin. The tension-releasing incisions are then allowed to heal by secondary intention and are covered with non-adherent dressings to prevent drying of the skin edges as the incisions heal completely.

Figure 2.

Illustration of pie-crusting technique. (A) Open wound with loss of domain. (B) Multiple lines of sequential small incisions are made parallel to the wound. (C) Wound edges are approximated and the small incisions open up allowing for tension-release. (D) Wound edges are sutured. Illustrated by Tareq Kheirbek, MD ScM FACS.

In our practice, we initially used the pie-crusting technique on lower extremity fasciotomy wounds with great success. We later applied this approach for wound reconstruction of over-granulated posterior thighs fasciotomy wounds. The over-granulated tissue resulted in a significant distance between skin edges that posed a challenge to achieve a primary closure when the excess granulation tissue was excised. Pie-crusting of the skin on the posterior thighs allowed for primary closure of the wound with complete healing on 2-week follow-up, hence, avoiding skin grafting and prolonged wound management. We then expanded the application to the patient who is presented in this report. Overall, the procedure was well tolerated and the patient’s satisfaction at 12-month follow-up was encouraging. This is consistent with reports in the early description by DiStasio et al, where pie-crusting was preferred by patients over skin grafts.¹¹ Though pie-crusting requires creation of multiple new incisions that must heal by secondary intention, our patient did not report any discomfort at the sites of his scarring and there was minimal discolouration and no hypertrophy. Consistent with other reports, in our prior experience when applying the technique on extremity wounds, there was a complete healing of the incisions without a significant scar formation. The cosmetic result of applying pie-crusting to abdominal wound should still be considered. The final result could be related to the size of incisions, the degree of underlying tension or factors related to external exposure of the wounds. Further application of the technique in other patients would allow us to make a better assessment of the cosmetic results.

There were no immediate or long-term infectious complications at the surgical sites. The resulting hernia was acceptable to the patient, and anecdotally significantly smaller than those we encountered with skin grafting directly over abdominal contents. We believe the full thickness of subcutaneous tissue covering the fascial defect resulted in less discomfort with the hernia compared with when patients undergo skin graft coverage. We anticipate this could change with time and further discussions with the patient regarding hernia repair continue to be had. Though some patients may express concern over the cosmetic outcomes associated with pie-crusting, the benefits of durable abdominal wall coverage should not be overlooked. The immediate and long-term satisfaction should be compared with that following STSG coverage, which is much thinner and is associated with a prolonged healing process of the abdominal wound and the donor site.

Surgeons should further consider the impact of pie-crusting on eventual hernia repair with possible need for a component separation. The small incisions that are created result in minimal disruption to the underlying subcutaneous tissue. The anecdotal near-complete healing of the pie-crusting incisions likely results in minimal additional difficulty in creating skin flaps to perform abdominal wall component separation. In fact, the hernia repair in this case would avoid the need for skin graft excision that could be extensive following STSG coverage. However, due to absence of a description of abdominal hernia repair after pie-crusting closure, we cannot definitely indicate the difficulties associated with the technical aspect of such repair, yet. As we continue to consider pie-crusting for abdominal wound closure, our team will report on the ensuing abdominal wall reconstruction in the future.

It is imperative to state that the preoperative consent should include review of anticipated cosmetic and functional outcomes, and the authors hope that this case report may provide an illustration for patients and surgeons alike. The images from our earlier experiences were used when obtaining an informed consent from this patient’s surrogate, since he was critically ill and sedated. Additional photos are collected as we continue to perform the procedure for various wounds. They are used to facilitate the consent process by providing visual aids that help the patients or their surrogates understand the healing process when considering different treatment options.

Learning points.

• Pie-crusting is a valuable method for reducing incisional tension to achieve primary closure in patients who aim to avoid split thickness skin grafting to the trunk or extremities.

• Prior to pie-crusting, patients—or their surrogates if patients are medically sedated due to critical illness—must be explicitly informed of and express clear understanding of the subsequent tension-releasing incisions that must heal by secondary intention.

• We strongly encourage the use of photographic or visual aids to guide expectations and inform shared decision-making around pie-crusting and split thickness skin grafting. Our team uses photographs of open wounds, wounds that were covered by skin grafts and wounds that were closed using pie-crusting technique to confirm that the patient is well informed of her/his options.

• Closure of surgical wounds under tension requires careful consideration of patient preferences and functional requirements in addition to healing potential and durability of repair

Ethics statements

Patient consent for publication

Obtained.