Patient characteristics. A total of 10 patients (8 women, 2 men, median age 55.4 [range 44–71] years) with an EAF were treated. Indications for OA treatment included severe abdominal sepsis due to intestinal perforation, anastomotic dehiscence, and ileus (see Table 1). Two (2) patients were transferred from other hospitals after the index operation; 1 patient was treated before the transfer in a different department of UKF. Five (5) patients developed the fistula in the direct course of a malignant disease, 3 patients had a history of cancer, and the remaining 2 patients had no malignant disease. Comorbidities included diabetes (1 patient), hypothyreosis (3 patients), and Factor V Leiden mutation (1 patient).
Surgical aspects and fistula characteristics. Among the 10 patients, 4 developed fistulas after small bowel resections, 2 underwent anterior rectum resection (1 for cancer, 1 for rectal prolapse), 1 underwent pylorus-preserving pancreatoduodenectomy, 1 had a right hemicolectomy, and 1 had a relaparotomy and revision of a colostomy and a multivisceral resection due to ovarian cancer. The median time from the index operation to the OA treatment was 11.5 (range 3–25) days, in which patients underwent repetitive reoperations, resulting in the OA. Two (2) patients were transferred with an OA to the authors’ department. In 4 patients, the OA was installed during reoperation because of persisting abdominal sepsis; in 2, this was a result of fascia and skin retraction. The median time from the index operation to the development of a fistula was 12.5 (range 3–25) days.
Seven (7) patients developed a complete fixed bowel package (referred to as a frozen abdomen) with grade 4 fistulas according to the Björck classification system.14 The remaining 3 patients had a grade 3 OA. Nine (9) patients had high-output fistulas (>500 mL/24 hours).17
Eight (8) patients developed multiple fistulas, leading to a median fistula rate of 2.5 (range 1–6 fistulas). In 7 patients, the first fistula was located between the flexura duodenojejunalis and the first 60 cm of jejunum (upper jejunal fistula [UJF]). No gastroatmospherical fistulas occurred. All patients with an UJF had more than 1 fistula. In these patients, the exact locations of the further fistulas could not be estimated via x-ray enteroclysis.
All patients were treated for OA using NPWT as described for a median of 104 (range 14–337) days. In 2 patients, NPWT was continued until reconstruction of the gastrointestinal passage and in 3 patients until reconstruction of the abdominal wall. In the remaining 7 patients, NPWT was discontinued after the establishment of a surface that allowed a safe treatment with laparostomy or stoma pouches (SenSura®, Assura®, Coloplast®, ClickXPro® [Coloplast, Hamburg, Germany] or Wound Pouches™ [EAKIN GmbH, Munich, Germany]).
Nutritional aspects. All patients with fistulas received EN during the hospital stay with a median time from the first appearance of a fistula to the first administration of EN of 11.5 (range 5–105) days and 32.5 days to a full-calorie enteral intake, respectively. One (1) patient successfully implemented a 25 kcal/kg/day oral diet within 5 days after the appearance of the OA with EAF and received no PN, whereas 9 patients received additional PN equivalent to their calculated needs. Septic patients with hypovolemia and severe hypoalbuminemia below 1.9 g/dL were substituted with human albumin 20% in the course of their treatment, making it impossible to use serum albumin levels for nutrition monitoring during the initial phase of fistula development.
Initial weaning from PN was achieved in 6 of the 9 patients; of these, 4 with UJF required additional PN. PN eventually was reduced in volume or frequency in 3 of these patients. Patients without an UJF were successfully weaned from PN and remained on an oral diet (see Table 2).
Outcome and complications. The median hospital stay following the index operation and formation of the EAF was 107.5 (range 42–371) days. A comparison between patient BMI at admission (BMI-A) and discharge (BMI-D) revealed a significant loss of weight in all patients (mean BMI-A 27.7 [range 23.4–39.9] versus BMI-D 21.4 [range 14.4–26.8]; P <0.001).
The wound and fistula condition improved as rated during the daily rounds and documented in the patient file (including photo documentation) in all but 1 patient after initiating EN. Median fistula volume as well as maximum volume per day did not change significantly after initiating EN (median volume: 970 mL [range 230–1820 mL] versus 720 mL [range 200–1370 mL]); maximum volume per 24 hours: 1880 mL [range 400–4600 mL] versus 2520 mL [range 700–6900 mL]; P = 0.25) (see Table 3). The maximum fistula volume per 24 hours increased in 8 of the 10 patients after initiating EN, whereas the median fistula volume decreased in all patients. No association between peak fistula volume and the initiation of EN could be observed.
In 6 of the 8 patients provided NPWT at the initiation of EN, the frequency of NPWT dressing changed from the original schedule of every third day. Five (5) needed NPWT changes less frequently than before EN (mean PN 2.35 [1.5–2.75] days versus EN 2.96 [2.7–3.3] days; P = 0.19). Only 1 patient (12.5%) needed the NPWT dressing changed more often (3 (EN) versus 2.3 (PN) days between dressing changes).
Six (6) patients experienced local complications before initiating EN: 1 experienced light skin irritation, 4 had moderate complications (severe skin irritation, failure of NPWT, need for additional medication), and 1 had severe complications (additional operative intervention, dressing changes under general anesthesia). Of those, local complications improved (4 had light skin irritation with additional dressing changes and 2 had moderate to severe skin irritation and failure of NPWT) after initiating EN. One (1) patient (the same patient that required more frequent dressing changes) without local complications before EN developed moderate complications (severe skin irritation) after EN was started.
Electrolyte disorders were noted in 6 patients, reversible liver failure in 3, and severe disturbance of blood sugar levels in 1 patient. Only in 1 case were severe electrolyte disorders clearly linked to PN. Central venous catheter thrombosis occurred in 2 patients, and 1 patient experienced catheter-associated problems requiring additional surgery that led to further complications.
Six (6) patients developed feeding intolerance following EN: diarrhea occurred in 3, vomiting in 4, and 2 suffered from both, but it was not necessary to stop EN. All 8 patients capable of oral food intake with additional PN reported a lack of appetite. No patient aspirated or had GI bleeding or ileus during the hospital stay.
After initiating EN, 2 patients had an increase of serum creatinine linked to dehydration. Both patients needed parenteral fluids initially; 1 patient increased oral fluid intake and did not need additional parental fluids at discharge.
Seven (7) patients underwent reconstruction of the gastrointestinal tract and the abdominal cavity, 3 within the initial stay. One (1) patient refused a reconstructive operation; another was scheduled for 6 months after the index operation.
Two (2) patients died during the initial stay: 1 of a severe apoplexy, possibly linked to a thrombosis of an intraport catheter implanted for PN, and the other of septic complications leading to renal, kidney, and respiratory failure during the initial stay (hospital mortality rate of 20%). One (1) patient, initially discharged, died following the reconstruction operation due to thromboembolic complications caused by a Factor V Leiden thrombophilia and septic complications. During follow-up, another patient died after successful reconstruction and discharge due to hepatic, pulmonary, and peritoneal metastasis of her pancreatic cancer.