A Case Series of Successful Abdominal Closure Utilizing a Novel Technique Combining a Mechanical Closure System with a Biologic Xenograft that Accelerates Wound Healing

Summary

Closure of catastrophic open abdominal wounds presents a challenge to the surgeon. We present a surgical technique utilizing a combination of mechanical and biologic xenograft closure systems in closing complex open abdominal wounds. This technique offers another option to the surgeon for definitive fascial closure and accelerated wound healing.

Abstract

In the acute setting, once intra-abdominal injuries have been addressed, the next great hurdle is restoring a functional and intact abdominal compartment. The short and long-term consequences of living with a chronically open abdominal compartment include pulmonary, musculoskeletal, gastrointestinal, and emotional disability. The closure of catastrophic open abdomens presents a challenge to the surgeon. We present a technique utilizing a mechanical abdominal closure device in conjunction with biologic xenograft in closing complex open abdomens. This technique offers another option for definitive fascial closure and accelerated wound healing in this difficult patient population. The dynamic tissue system (DTS) is installed after control of original intraabdominal pathology. A porcine urinary bladder matrix (PUBM) is then placed in the subcutaneous space once fascial closure is achieved. Overall, primary myofascial closure was achieved in 100% of patients at a mean of 9.36 days.

Introduction

The increasing prevalence of abdominal compartment syndrome (ACS) has led to an emergence of various temporary abdominal closure (TAC) techniques¹. TAC is performed to prevent evisceration, assist in the removal of unwanted intraperitoneal fluid, minimize intra-abdominal complications, and expedite the closure of the abdominal cavity². Closure of an open abdomen facilitates restoration of normal physiology in the patient³. Prolonged duration of an open abdomen results in complications such as fistula formation and an inability to close the abdomen⁴. There are several methods to achieve final closure of an open abdomen.

The simplest way to temporarily close an abdomen is by using towel clips to close the skin⁵. One of the most commonly used and studied abdominal closure techniques is negative pressure wound therapy (NPWT)⁵. For the NPWT, a nonadherent barrier to protect the intraabdominal contents is applied followed by a moisture-absorbing sponge-like material, an outermost adhesive layer to sure the dressing in place, and a negative pressure mechanism⁶. A Bogota bag can also be used for temporary closure of an open abdomen. A Bogota bag is an empty intravenous fluid bag cut in half and sutured to skin edges⁷. NPWT and the Bogota bag closure are two temporizing measures that facilitate delayed primary closure of the abdominal cavity⁷.

Once the abdomen is deemed ready for closure, different closure methods can be utilized. The simplest way is to apply a split-thickness graft over the omentum once it has formed healthy granulation tissue. If the wound is not contaminated, a nonabsorbable synthetic sheet may be used to bridge the fascial edges⁸. If the fascial gap is less than 14-20 cm in maximal diameter, component separation of the rectus sheath can be performed⁹.

Some abdominal closure techniques allow for gradual reapproximation of the fascial edges and eventual primary closure¹⁰. A Wittmann patch consists of two opposing Velcro sheets that are sutured to each fascial edge¹¹. The opposing sheets are then fastened together in the midline. This mechanism allows easy re-entry into the abdomen and adjustment for abdominal compartment pressures. Additionally, this can provide midline traction on the fascial edges that can prevent retraction of the fascial edges and also facilitate primary closure of the fascia.

Alternatively, a DTS is available and is part of the technique described in this paper. The described DTS is composed to a silicone viscera protector that is applied over abdominal contents to prevent adhesions and adherence of viscera to the abdominal wall. Adjustable elastomers then penetrate the full abdominal wall thickness on each side and provide medializing dynamic tension, allowing relaxation of the flat muscles (obliques and transversus abdominus). This allows medialization of the rectus myofascial units (Figure 1). A product composed of porcine urinary bladder extracellular matrix can be placed in the subcutaneous space once primary myofascial closure is achieved (Figure 2). Porcine xenograft placement in the subcutaneous space augments and expedites wound healing through angiogenesis, innervation, modulation of the inflammatory response, and resistance to infection¹².

In this study, we describe a novel technique of primary abdominal closure following abdominal compartment syndrome utilizing a dynamic closure system and a biologic xenograft. At our level 1 trauma and acute care center, abdominal compartment syndrome is a common diagnosis. Prior to utilization of this novel method, most catastrophic open abdomens were not amenable to primary closure and a skin graft was placed over the viscera or bridging mesh. Since the adoption of this method in May of 2016, we have closed 100% of open abdomens due to abdominal compartment syndrome in a high-risk population (average BMI 40.45, SD 9.83) (Table 1).

Protocol

1. Installation of Dynamic Tissue System

1. Exclude if there is hemodynamic instability, a need for further abdominal washouts, or a concern for intraabdominal sepsis.
   1. If an ostomy exists, trim the ostomy wafer to make as narrow as possible and outline on abdominal skin. Cover ostomy with 4x4 and secure in place with adhesive transparent film dressing.
   2. Apply antimicrobial betadine impregnated adhesive drape to the skin of the abdomen widely, covering the operating field.
   3. Wash the abdomen out with at least 2 L of 40.5° C normal saline.
   4. Measure and record the myofascial gap (MFG), visceral extrusion (VE), and the length of incision in centimeters for documentation of progress on the operative note.
   5. Mark the skin of the anterior abdominal wall 5 cm laterally from medial fascial edge to create an ellipse around the midline wound.
   6. Place the elastomer buttons side by side on the ellipse created in step 1.1.5. with the “U” of the elastomer at the 5 cm ellipse demarcation around the midline wound. This will assure 3 cm spacing as recommended.
   7. Create superficial thickness dermotomies with an 11 blade.
   8. Pull the elastomer through the abdominal wall using the cannulator.
   9. Repeat the same steps on the opposite side. This time pull the elastomer across the myofascial gap and secure both ends with a hemostat.
   10. Loosely attach the elastomer bands to the elastomer buttons. Do not tighten elastomer bands.
   11. Attach elastomer adhesion stickers on the button tails.
   12. Perform osteopathic maneuvers throughout installation. This is performed with two people standing on either side of the patient. Apply bimanual forces in the flank area, gently massaging towards the midline and create circular motions synchronized with the other operator first towards the head and then creating circular motions towards the feet.

2. Silicone Visceral Protector Inserted

1. Insert silicone visceral protector midline over abdominal viscera, taking care to protect any ostomies (Figure 3).
2. Envelop the abdominal viscera with silicone visceral protector down to each paracolic gutter.
3. Create necessary cut outs in the visceral protector with scissors to protect the ostomies.
4. Place elastomer retainer in the midline on top of visceral protector and evenly space elastomer bands into the retainer (trim to size).
5. Adjust elastomer bands slowly in between osteopathic maneuvers.
6. Stop elastomer adjustments when tension hashmarks across the MFG is 1.5 – 2x stretch.
7. Record the MFG and VE with a ruler in centimeters at the start, install, and completion (Figure 4).

3. Installation of Negative Pressure Wound Therapy Device

1. Make NPWT device sponge as thing as possible and place in the midline above the elastomer retainer (Figure 5).
2. Cover with vacuum drape tape and apply the negative pressure device with continuous suction at -100 mmHg.
3. Perform osteopathic maneuver a few more times.

4. Elastomer Adjustment

1. Bring the patient back to operating room, or if your facility has the capability to perform in ICU, periodically. First elastomer adjustment can be 2 – 5 days after installation.
2. Remove the NPWT device overlying the midline wound with scissors, taking care to leave the adhesive iodine drape on the skin intact.
3. Prep the abdomen widely including the elastomers in place with 4% chlorhexidine gluconate.
4. Perform osteopathic maneuvers intermittently throughout procedure. See step 1.1.12. for details.
5. Record the MFG and myofascial apposition (Figure 6).
6. Irrigate the midline wound with at least 2 L of 40.5° C normal saline, taking care not to spill water on the DTS or the antimicrobial iodine impregnated adhesive drape.
7. Adjust elastomers by releasing the elastomer from the anchor and pulling each elastomer laterally, away from the midline.
8. Reapply the black sponge NPWT device.

5. Fascial Closure

1. Bring the patient back to the operating room. Prep widely.
2. Remove the elastomer retainer.
3. Remove the visceral protector and irrigate the abdominal cavity with at least 2 L of normal saline.
4. Close the fascia in a bi-directional fashion utilizing a Smead-Jones technique and a #2 vicryl suture on a TP1 needle.
5. Irrigate and dry the midline wound.
6. Apply PUBM micromatrix powder to the midline wound and evenly distribute the powder so that the newly created linea alba is covered in PUBM micromatrix.
7. Hydrate a two-layer, 10x15 cm, PUBM wound sheet and delaminate so there are 2 single sheets. Apply the sheets on top of the powder to cover the entire midline wound surface (Figure 7).
8. Appose skin edge with strips of vac drape tape (Figure 8).

Representative Results

We have analyzed a total of 11 patients so far with catastrophic open abdomens. Primary myofascial closure was achieved at a mean of 9.36 days. We had 0% surgical site infections (SSI) and achieved 100% primary myofascial closure. No enteroatmospheric fistula resulted in this technique, unless present prior to this DTS and xenograft approach. Since May 2016, zero open abdomens were left open or covered with a skin graft (Figure 9).

The results of this study show that the use of a dynamic mechanical closure device system with porcine urinary bladder matrix achieved closure in 100% of the patients with catastrophic abdomens. The system provides dynamic, and therefore more physiologic, appositional traction from the fascial layer up to the skin using elastomers. A recent meta-analysis that included 251 studies and 13,650 patients showed that negative pressure wound therapy with continuous fascial traction (with either mesh or tension sutures) had the highest weighted rate of definitive fascial closure of 76% in 26 series^12,13,14. The weighted definitive fascial closure rates were 75% with the Wittmann patch (8 series), 73% with the dynamic retention sutures (5 series), 54% with negative pressure wound therapy alone (106 series), 50% with loose packing (25 series), 25% with zipper (14 series), 39% with mesh (43 series), and 37% with Bogota bag (24 series)¹².

Although our institution did not close septic patients with this technique, an 18-patient study evaluating the use of DTS system in closing open abdomens in septic patients showed successful closure in 88% of the studied patients¹⁴. The mean number of days the DTS remained in place until closure in the aforementioned studies ranged from 10-48 days^12,13,14,15.

Our study only included 11 patients, three of whom had ostomies in place. Our technique achieved 100% closure rate with an average of 9.36 days from DTS application to fascial closure. The use of a xenograft matrix allowed closure of the subcutaneous space and skin after fascial closure despite our study population having an average BMI of 40. The results of our study conclude that the use of the dynamic tissue system achieves excellent results in definitive closure of the open abdomen.

	Mean	Standard Deviation
Age (years)	48.11	10.03
DMI (kg/m2)	40.45	9.83
Visceral Extrusion (cm)	6.8	1.57
Incision Length (cm)	26.55	10.13
Days to Closure of Fascia	9.36	4.18
Adjustments of DTS Prior to Closure (DTS)	1.82	0.98
Days Abdomen Open Before DTS Application	8	9
Myofascial Gap Before DTS Application (cm)	18	6
Myofascial Gap After DTS Application (cm)	9.06	2.04

Table 1. Review of 11 patients who underwent novel dynamic tissue system closure with biologic xenograft placement to midline wound at a single level 1 trauma center.

1. Obstructing rectal cancer with gangrenous colon

2. Exploratory laparotomy x2, Aortic dissection status post thoracic endovascular aortic repair, open gastrotomy, splenectomy, colectomy

3. Severe Acute Hemorrhagic Pancreatitis with Colopancreatic Fistula

4. Auto versus pedestrian, abdomincal compartment syndrome, splenic Laceration, acetabular fracture, bladder injury with suprapublic cystostomy

5. Incisional hernia, Crohn's disease, small bowel obstruction

6. Enteroatmospheric fistula, skin grafted open abdomen after prostatectomy

7. Motor vehicle crash, splenectomy, paraplegia from cervical spine injury, small bowel obstruction, gastrojejunostomy, partial abdomincal closure, pulmonary embolus

8. Abdominal compartment syndrome (due to excessive crystalloid resuscitation and delay in definitive management of massive upper gastrointestional hemorrhage)

9. Incisional hernia with loss of domain and obstructing jejunal adenocarcinoma

10. Diverticulitis, attempted Hartmann's reversal, massive venous hemorrhage

Table 2: Reasons for open abdomens and abdominal compartment syndrome at our level I trauma center.

Figure 1: Dynamic Tissue System (DTS). Image provided courtesy of Southmedic Inc. 

Figure 2: Porcine urinary bladder extracellular matrix comes in wound sheet and wound powder. The powder and sheet are combined together to accelerate and expedite wound healing. Image provided courtesy of ACell, Inc. 

Figure 3: Abdominal visceral protector is in place, the elastomer holes have been made with puncture device, and then elastomer bands pulled through on each side. Hemostats are placed on elastomers to avoid pulling through the abdominal wall. Note the abdominal wall markings of an ellipse. The elastomer bands are gathered loosely at midline ready to place an elastomer retainer.

Figure 4: The elastomer retainer is placed in midline above visceral protector. Elastomer bands are then placed in the elastomer retainer. Myofascial gap is then recorded.

Figure 5: Negative pressure wound therapy device is applied and connected to suction. 

Figure 6: Elastomers are adjusted in 48 hours after initial DTS installation and myofascial gap is measured prior to and after adjustment.

Figure 7: Fascia is closed and wound matrix powder and sheet is laid in midline. 

Figure 8: Midline wound is brought together with vacuum drape tape that has been cut into 2 inch strips across abdominal wall. Ostomy appliance is then applied.

Figure 9: Same patient who survived severe necrotizing pancreatitis with abdominal compartment syndrome is shown above at her six week clinic follow-up appointment. Midline wound is completely healed. Fascia is intact and no hernia is palpable. Her fascia was closed after 10 days of having an open abdomen.

Discussion

The most critical step of the protocol for closing a complex abdominal wound is performing osteopathic maneuvers before elastomer placement, after elastomer placement, and before and after elastomer adjustments. In addition, we perform osteopathic maneuvers on these patients after surgery three times a day, for at least five days. Our approach describes the use of osteopathic maneuver prior and after elastomer adjustments. The anecdotal observation has been that these maneuvers aid in fascial approximation, by facilitating relaxation of the flat abdominal muscles. Although we did not record the fascial edges prior and after the osteopathic maneuvers, we do feel that this step is crucial. There are no studies available at the time of this paper on the benefit of osteopathic maneuvers and fascial approximation. A study using a mathematical model found that tangential and compressive forces on the skin are transmitted to the fascial layer¹⁵. This force allows approximation of the fascia. 

Another critical step of the protocol is to not too adjust the elastomers too frequently and only to a maximum of 1.5 – 2X the tension markings stretch. At times when abdominal closure was extremely difficult, patients were paralyzed in the intensive care unit with rocuronium and sedatives to keep intraabdominal pressure low. The average time length of paralysis was 3.4 days. 

The use of iodine impregnated adhesive tape and moisture-wicking fabric around elastomers and under the buttons, is a modification of our technique that keeps the surgical site clean and free on infection. This is one of the key reasons our surgical site infection rate was 0% in a patient population at high risk of surgical site infections. 

At the present moment, we have not found any limitations to the technique. One limitation that may occur is the cost of the dynamic closure system (USD$5500) and porcine urinary bladder matrix (USD$1000 per sheet, USD$1000 per powder bottle). In addition, frequent take backs of patients to the operating room for adjustments and prolonged time in the intensive care unit add on costs. However, a cost analysis needs to be performed into the quality of life post closure. In addition, our rate of incisional hernia is 0%. Operation on recurrence of hernia, possibility of bowel obstruction, and return to hospital may need to be factored into cost savings of our protocol. 

Future applications of this technique include closure of extremity wounds, fasciotomy wounds, and large traumatic soft tissue wounds. Most striking is the reality that without this approach, chronic massive incisional hernias and loss of domain is the norm. Future studies need to include cost-analysis of this technique.

Materials

Name	Company	Catalog Number	Comments
ABRA Abdominal Wall Closure Set	Southmedic	CWK08 Abdominal
3M Ioban 2 Antimicrobial Incise Drape	3M	6651EZ
MicroMatrix Micronized Particles 200 mg	ACell	MM0200
Cytal Wound Matrix 2-Layer 10 x 15 cm	ACell	WSM1015
Negative Pressure Therapy System	KCI	09-03-193.ABT.IE