Table 2 Statement Grid

 ➢ Peritonitis

The open abdomen is an option for emergency surgery patients with severe peritonitis and septic shock under the following circumstances: abbreviated laparotomy due to the severe physiological derangement, or the need for a deferred intestinal anastomosis or a planned second look for intestinal ischemia, or persistent source of peritonitis (failure of source control), or extensive visceral edema with the concern for development of abdominal compartment syndrome (Grade 2C).

 ➢ Vascular Emergencies

The open abdomen should be strongly considered following management of hemorrhagic vascular catastrophes such as ruptured abdominal aortic aneurysm (Grade 1C)

The open abdomen should be considered following surgical management of acute mesenteric ischemic insults (Grade 2C).

 ➢ Pancreatitis

In patients with severe acute pancreatitis unresponsive to step-up conservative management surgical decompression and leaving the abdomen open is effective in treating abdominal compartment syndrome (Grade 2C)

Leaving the abdomen open after surgical necrosectomy for infected pancreatic necrosis is not recommended excepted in those situation at high risk of abdominal compartment syndrome (Grade 1C)

Optimal technique for temporary abdominal closure

Negative pressure wound therapy with continuous fascial traction is suggested as the preferred technique for temporary abdominal closure (Grade 1B).

Temporary Abdominal Closure without Negative pressure wound therapy (e.g., mesh alone, Bogota bag) whenever possible should NOT be applied for the purpose of temporary abdominal closure, because of low delayed fascial closure rate and being accompanied by a significant intestinal fistula rate (Grade 1B).

Is there a role for NPWT with Fluid Instillation?

There is inadequate evidence to make a recommendation regarding use of negative pressure wound therapy in combination with fluid instillation in patients with temporary abdominal closure (NOT GRADED).

Planning re-exploration before definitive closure

- In critically ill non-trauma patients with open abdomen, once any requirements for on-going resuscitation have ameliorated, early re-operation with the intention of closing the abdomen should be given a high priority (Grade 1C).

- In critically ill patients with open abdomen, re-laparotomy with concern for ongoing ischemia/contamination reoperation should be conducted no later than 24–48 h after the index operation, with the duration from the index operation shortening with increasing degrees of patient non-improvement and hemodynamic instability (Grade 1C).

Best timing to definitively close an open abdomen

- Fascia should be closed as soon as possible (Grade 1C).

- Acidosis (pH <7.25), hypothermia (temperature < 34 °C) and coagulopathy (TEG, INR) are not predictive of the need for maintaining the open abdomen in non-trauma patients (Grade 2A).

- The abdomen should be maintained open in non-trauma patients if the source of contamination persists, if a condition of haemodynamic instability persists meaning in presence of on-going fluid resuscitation or vasopressor support necessity, if a deferred intestinal anastomosis is needed, if there is the necessity for a planned second look for ischemic intestine and lastly if there are concerns about abdominal compartment syndrome development (Grade 2C).

- Early fascia closure (within 7 days) should be the strategy for management of the open abdomen once the source control has been reached, the severe sepsis has been controlled meaning that the patient is haemodynamically stable and the hypoperfusion has been definitively corrected, no further surgical re-exploration is needed and there are no concerns for abdominal compartment syndrome (Grade 2C).

 ➢ Non-mesh mediated techniques

- Primary fascia closure is the ideal solution to restore the abdominal closure (2A).

- Component separation is an effective technique; however, it’s early use is NOT recommended in fascial temporary closure. It should be considered only for definitive closure or reconstructive interventions (Grade 2C)

- Planned ventral hernia (skin graft or skin closure only) remains an option for complicated open abdomen (i.e. in the presence of entero-atmospheric fistula or in cases with a protracted open abdomen due to underlying diseases) or in those low resource setting where no other facilities are present (Grade 2C)

 ➢ Mesh mediated techniques

- A fascial bridge using prosthetic mesh (polypropylene, polytetrafluoruroethylene (PTFE) and polyester products) should NOTt be recommended to achieve definitive fascial closure in patients with open abdomen and should be placed only in patients without other alternatives (Grade 1B).

- Biologic meshes are reliable for definitive abdominal wall reconstruction in the presence of a large wall defect, bacterial contamination, comorbidities and difficult wound healing. NPWT can be used combined with biologic mesh to facilitate granulation and skin closure (Grade 2B).

- Non–cross-linked biologic meshes seem to be preferred in sublay position when the linea alba can be reconstructed. Non–cross-linked biologic mesh is easily integrated, with reduced fibrotic reaction and lesser infection and removal rate (Grade 2B).

- The long-term outcome of a bridging non–cross-linked biologic mesh is laxity of the abdominal wall and a high rate of recurrent ventral hernia. In the bridge position (no linea alba closure), cross-linked biologic meshes maybe associated with less ventral hernia recurrence (Grade 2B).

Best treatment for open abdomen and entero-atmospheric fistulas

- Several clinical circumstances may contribute to the development of entero-atmospheric fistula and few risk factors may predict its development. Awareness of this complication and avoidance of contributing conditions for its development are mandatory; moreover preemptive measures are imperative (Grade 1C).

- The management of entero-atmospheric fistula should be personalized according to standard classification and grading system. Current different classification schemes echo the problematic and challenging issues related to their management (Grade 1C)

- The caloric intake and protein demands of patients with entero-atmospheric fistula increase; the Nitrogen balance should be corrected and protein supplemented. Nutrition should be started immediately upon recognition of entero-atmospheric fistula (Grade 1C)

- Entero-atmospheric fistula effluent isolation is essential for proper wound healing. Separating the wound into different compartments in order to facilitate the collection of fistula output is of paramount importance (Grade 2A).

- Many methods for wound care exist; however in the presence of entero-atmospheric fistula in open abdomen, negative pressure wound therapy makes effluent isolation feasible and wound healing conceivable (Grade 2A).

Definitive management of entero-atmospheric fistula should be delayed to after the patient has recovered and the wound completely healed (Grade 1C).

Nutritional support

- Open abdomen patients are in a hyper-metabolic condition; an immediate and adequate nutritional support is mandatory (Grade 1C).

- Open abdomen techniques result in a significant nitrogen loss that must be replaced with a balanced nutrition regimen (Grade 1C).

- Early enteral nutrition should be started as soon as possible if the gastrointestinal tract allows (Grade 1C).

- Enteral nutrition should be delayed in patients with high output fistula with no possibility to obtain feeding access distal to the fistula (Grade 2C)

- Oral feeding is not contraindicated; whenever it’s possible it could be started as soon as the patient is able to eat (Grade 2C).

Patient Mobilization

- To date, no recommendations can be made about early mobilization of patients with open abdomen.