Editing Open abdomen (section)

=== '''Phase 1: Initial laparotomy and use of temporary closure device''' ===

* '''Indications for temporary abdominal closure (open abdomen)'''
** Patients with/at risk of IAH/compartment syndrome
** Damage control
*** Severe haemorrhage
*** Hypothermia, acidosis, coagulopathy
*** Delayed definitive operation secondary to patient's physiologic state
** Major abdominal and/or retroperitoneal tissue oedema
** Questionable visceral viability
** Planned acute re-operation
** Severe intra-abdominal sepsis
** Triage
* '''Goals:'''
** Minimise damage to abdominal contents
** Minimise adherence of abdominal contents to anterior abdominal wall
** Retain the ability to close the fascia primarily at a subsequent operation '''(aim to close within 8 days - much higher rate of complications after this point)'''
* '''Techniques:'''
** '''Skin closure techniques'''
*** Simple running sutures
*** Sequential towel clip closure
*** Silo technique/Bogota bag
**** Suture an inert, non-permeable barrier (IV bag etc) to the skin or fascia
**** Prone to leakage/evisceration
**** Do not prevent retraction
**** Do not allow effective removal of abdominal fluid
**** Rates of primary closure are mostly <30%
** '''Fascial closure techniques'''
*** Vicryl/biological mesh, polypropylene mesh, Wittman Patch, Esmark bandages, expanded PTFE
*** Should initially be loose to allow for visceral swelling without ACS
*** Do not prevent adhesions to anterior abdominal wall
*** For non-absorbable meshes, fistula formation is very high (6-18%) if a non-adherent barrier is not placed under the mesh (omentum, Ioban sheet)
*** Sequentially tightened by excising the central part and resuturing the fascial material closed
*** Should typically be tightened every 24-48 hours until the fascia is 2-4cm apart, at which point the fascia is closed primarily
*** Most useful when an extended duration of laparostomy is predicted (unlikely to be closed by 8 days)
** '''Negative pressure applications'''
*** ABThera - inner plastic-encased sponge designed to be indirect contact with the viscera, followed by a macroporous foam sponge, followed by adhesive dressing
**** Tips for ABThera
***** Maximally lateralise the internal visceral layer - prevents bowel from slipping out, and prevents adhesions. Some suggest taking down falciform ligament to help get it right into paracolic gutters.
***** Bury any intestinal anastomoses deep in abdominal cavity
***** Test thoroughly for leaks (can use tincture of benzoin)
***** Can use staples to fix sponge to skin edges (need it flush, as any contact of skin to sponge can damage epidermis, but you also want full coverage of wound)
***** Ostomy appliances should be OVER the adhesive layer, not under, or you risk sucking poo into the wound
***** Get the hole sized right - many manufacturers suggest 2x2cm
***** Adjust suction level as needed - 125mmHg is optimal for wound healing, but put down to 75mmHg if there is bleeding/coagulopathy
*** Low rate of fistulas (but beware of anastomoses directly under the pack and intra-abdominal sepsis), average primary closure rate of 67%
*** Highest primary fascial closure rates when the VAC is used in conjunction with a fascial tension device (such as simple interrupted fascial sutures which are added/tightened each relook)
* '''Choice of initial technique'''
** My approach:
*** Definitely one relook: Abthera/VAC 
*** Going to need multiple relooks: Large polypropylene mesh, with Ioban on each side, then VAC over the top
** Consensus guidelines recommend NPWT techniques initially, during the resuscitative phase where risk of ACS is highest
** NPWT is especially favoured in inflammatory pathologies - highest delayed primary closure rate, lowest mortality, lowest ECF formation