Acellular dermal matrix provides a good option for abdominal wall closure following small bowel transplantation: a case report.

Following small bowel transplantation (SBTx), approximating the midline abdominal fascia can be problematic in patients with severely retracted abdominal cavities. We first report the use of acellular dermal matrix (ADM) for abdominal closure following living related SBTx. A 44-year-old woman with ultra-short gut syndrome secondary to multiple bowel resections received a 160-cm segmental intestinal graft from her daughter. The graft ileocolic vessels were anastomosed end to side to the inferior vena cava and distal aorta. A terminal ileostomy was fashioned because the patient had previous panproctocolectomy. The graft perfused well, and the laparotomy was primarily closed. On postoperative day 1, the patient required surgical exploration for evacuation of hematoma. Due to graft edema in a significantly retracted abdominal cavity, a 12x7 cm fascia defect was evident. Leaving the abdomen open or using a mesh was not entertained as options due to the high risk of infections. Primary closure under tension would also jeopardize the transplant, increasing the risk of thrombosis. The fascia defect was closed using a segment of ADM. The patient did well and went home on the postoperative day 11. At 2-year follow-up she is well and on oral diet without fascia defect or incisional hernia. This is the first report of the use of ADM for abdominal closure in patients receiving a SBTx. ADM is considered safe when used in contaminated sites and can allow primary closure of difficult wounds often seen in SBTx patients.

Increased endothelin-1 in colorectal cancer and reduction of tumour growth by ET(A) receptor antagonism.

Endothelin-1 (ET-1) is a vasoconstrictor peptide which stimulates proliferation in vitro in different cell types, including colorectal cancer cells. Raised ET-1 levels have been detected both on tissue specimens and in the plasma of patients with cancers. To investigate the role of ET-1 in colorectal cancer: (i) ET-1 plasma levels in patients with colorectal cancer were measured by radioimmunoassay: group 1 = controls (n = 22), group 2 = primary colorectal cancer only (n = 39), group 3 = liver metastases only (n = 26); (ii) ET-1 expression in primary colorectal cancer specimens (n =10) was determined immunohistochemically and (iii) the effect of intraportally infused antagonists to the two ET-1 receptors, ET(A) and ET(B), on the growth of liver metastases in a rat model was assessed. ET-1 plasma levels were significantly increased in both patients with primary tumour and patients with metastases, compared to controls (P < 0.01, 3.9 +/- 1.4, 4.5 +/- 1.5, vs. 2.75 +/- 1.37 pg/ml, respectively). Immunohistochemically, strong expression of ET-1 was found in the cytoplasm, stroma and blood vessels of cancers, unlike the normal colon where only the apical layer of the epithelium, vascular endothelial cells and surrounding stroma were positively stained. In the rat model, there was significant reduction in liver tumour weights compared to controls, following treatment with the ET(A) antagonist (BQ123) 30 min after the intraportal inoculation of tumour cells (P < 0.05). These results suggest ET-1 is produced by colorectal cancers and may play a role in the growth of colorectal cancer acting through ET(A) receptors. ET(A) antagonists are indicated as potential anti-cancer agents.

Endothelin-1 and tumour development.

There has been a growing conviction amongst oncologists that cancer is a disease characterized by changes in specific molecules. These changes include alteration in the structure, regulation or quantity of growth factors and their receptors, signal transducers and the proteins encoded by dominant or suppressor/recessive oncogenes. The role of endothelin (vasoactive peptide) in tumour cell signal transduction and mitogenesis and induction of endothelial cell growth and angiogenesis in tumour growth is discussed in this article.

Localized intraoperative cardiac tamponade.

A 65-year-old lady had undergone mitral and aortic valve replacement following an open mitral valvotomy and aortic valve exploration 5 years earlier. At reoperation, following sternotomy, extensive adhesions were encountered and it was decided to perform minimal dissection of the heart. Both the aortic and mitral valves were replaced using 23 mm and 29 mm St. Jude bileaflet valves, respectively. At the end of the procedure it was difficult to wean the patient off bypass as her mean arterial pressure dropped and the heart became dilated. It was found that a tamponade had developed, as a result of bleeding from the vent site in the pulmonary artery, and dissected a plane between the heart and the adherent pericardium. Her condition improved dramatically as the tamponade was released and she came off cardiopulmonary bypass with no inotropic support.