Segmental arterial mediolysis: a rare cause of an acute abdomen.

Segmental arterial mediolysis (SAM) is a nonatherosclerotic, noninflammatory and nonimmune arteriopathy of unknown aetiology. We present the case of a 43-year-old male who presented to the emergency department with abdominal pain. A computed tomography of abdomen and pelvis showed a narrow, hypodense superior mesenteric artery after the origin, raising the possibility of thrombus or vasculitis. He was commenced on rivaroxaban and steroids. He subsequently presented with an acute abdomen in a collapsed state. Repeat imaging of his abdomen and pelvis revealed an ischaemic ileal segment and caecum. He required an emergency laparotomy with resection of the ischaemic segment and formation of a double-barrelled stoma. SAM is an important diagnosis for clinicians and radiologists to be aware of, given the risks of life-threatening haemorrhage and acute organ ischaemia. This is a commonly overlooked cause of abdominal pain, where an early diagnosis with lifestyle modifications may prevent disease progression and subsequent development of life-threatening complications.

Vascular endothelial growth factor and not cyclooxygenase 2 promotes endothelial cell viability in the pancreatic tumor microenvironment.

OBJECTIVES: Cyclooxygenase 2 (COX-2) and vascular endothelial growth factor (VEGF), often coexpressed in cancer, are associated with poor prognosis. However, results from pancreatic cancer trials of their inhibitors were disappointing. This study delineated the role of COX-2 and nonsteroidal anti-inflammatory drugs in angiogenesis and VEGF regulation. METHODS: AsPC-1 and BxPC-3 pancreatic cancer cells were cocultured with human umbilical vein endothelial cells (HUVECs). NS398 or VEGF-neutralizing antibody was added, and HUVEC viability assayed. Prostaglandin E2 and VEGF were quantified. Tumor cells were treated with NS398 or celecoxib, and VEGF quantified. RESULTS: In cocultures, HUVEC viability in AsPC-1 was 60% that of BxPC-3 controls (P < 0.05). Prostaglandin E2 and VEGF from BxPC-3 were double that of AsPC-1 (P < 0.05). NS398 reduced prostaglandin E2 to undetectable levels (P < 0.05) but had no effect on HUVEC viability. Vascular endothelial growth factor-neutralizing antibody reduced HUVEC viability in BxPC-3 wells to that of AsPC-1 (P < 0.05). NS398 had no effect on VEGF. Celecoxib increased VEGF in a concentration-dependent manner in each cell line up to 4-fold (P < 0.05). CONCLUSIONS: Cyclooxygenase 2 does not regulate VEGF in pancreatic cancer, and celecoxib upregulates VEGF in pancreatic cancer. It is VEGF, and not COX-2, inhibitors that reduce tumor-stimulated endothelial cell viability. Future pancreatic cancer trials should consider lower-dose nonsteroidal anti-inflammatory drugs in combination with VEGF inhibitors.

Autoimmune pancreatitis: medical and surgical management.

CONTEXT: Autoimmune pancreatitis is characterised by a lymphoplasmacytic infiltrate consisting in part of plasma cells that produce large amounts of IgG4. It can manifest as focal or diffuse enlargement of the pancreas with associated strictures of the pancreato-bilary tree giving rise to symptoms including abdominal pain, weight loss and obstructive jaundice; thus it can be extremely difficult in both presentation and investigation to distinguish from pancreatic carcinoma. Recent advances now facilitate preoperative diagnosis and effective medical management, including steroid treatment of autoimmune pancreatitis so preventing major surgical intervention. CASE REPORT: Two cases of autoimmune pancreatitis are described, each of which presented with obstructive jaundice and a relatively painless pancreatic mass, one with vascular involvement. They each had elevated serum CA 19-9 and ultimately required surgical exploration to definitely exclude malignancy before embarking on non operative treatment. The first case settled spontaneously while the second rapidly improved with steroid treatment. CONCLUSION: These two cases illustrate the difficulties in diagnosing this condition, the efficacy of steroid therapy and the role of surgical intervention in unresponsive cases or those where a diagnostic dilemma remains.