The ulnar nerve, origin C8-T1, is a continuation of the medial cord of the brachial plexus. This nerve passes in the same plane as the median nerve, between the biceps and triceps muscles. At the elbow, this nerve travels posterior to the medial epicondyle of the humerus. This means that condylar fractures can cause lesion to this nerve. Blood supply
The main artery in the arm is the brachial artery. This artery is a continuation of the axillary artery. The point at which the axillary becomes the brachial is distal to the lower border of teres major. The brachial artery gives off an unimportant branch, the deep artery of arm. This branching occurs just below the lower border of teres major. The brachial artery continues to the cubital fossa in the anterior compartment of the arm. It travels in a plane between the biceps and triceps muscles, the same as the median nerve and basilic vein. It is accompanied by venae comitantes (accompanying veins). It gives branches to the muscles of the anterior compartment. The artery is in between the median nerve and the tendon of the biceps muscle in the cubital fossa. It then continues into the forearm. The deep artery of the arm travels through the lower triangular space with the radial nerve. From here onwards it has an intimate relationship with the radial nerve. They are both found deep to the triceps muscle and are located on the spiral groove of the humerus.
An enterocutaneous fistula (ECF) is an abnormal communication between the small or large bowel and the skin that allows the contents of the stomach or intestines to leak through an opening in the skin. Causes
The mnemonic HIS FRIENDS can be used to memorize characteristics which impede the closure of  ECF.H: high output
I: IBD
S:short tract

F Foreign body
R Radiation
I Infection or Inflammatory bowel disease
E Epithelialization
N Neoplasm
D Distal obstruction
S Short tract (<2 cm)

Diagnosis
Classification
Congenital types: tracheoesophageal, vitellointestinal duct, patent urachus, rectovaginal
Acquired: trauma (postoperative), radiation, malignancy, infection

Two categories
Low-output fistula: < 500 mL/day
High-output fistula: > 500 mL/day

Three categories
Low-output fistula: < 200 mL/day
Moderate-output fistula: 200–500 mL/day
High-output fistula: > 500 mL/day

Treatment
The majority will close spontaneously within approximately 6 weeks. If it has not closed by 12 weeks, it is unlikely to do so and definitive surgery should be planned. The median time to definitive repair from fistula onset was 6 months (range 1 day to 28 months). The 6-month time course is commonly utilized by groups with significant experience treating fistulas, owing to the trend in encountering a less hostile abdomen than in the early phases. Some evidence also suggests that somatostatin can be an effective treatment with respect to reducing closure time and improving the spontaneous closure rate of enterocutaneous fistulas. References

Metcalf C (1999). "Enterocutaneous fistulae". Journal of Wound Care. 8 (3): 141–142. doi:10.12968/jowc.1999.8.3.25854.