Embryology, anatomy, physiology and pathophysiology of the peritoneum and the peritoneal vasculature.

The peritoneum is a large serous membrane with both epithelial and mesenchymal features, and is essential for maintaining an intra-abdominal homeostatic equilibrium. The peritoneum plays a central role in the pathogenesis of a number of disorders. Pathological processes affecting the peritoneum such as inflammation and carcinomatosis can have serious clinical consequences, but the pathophysiology of these conditions is poorly understood. Understanding peritoneal embryology, anatomy and physiology is crucial to comprehend pathophysiological mechanisms and to devise a new focus for research. The vascular response to pathological processes appears to be of considerable importance, since the peritoneal vasculature plays a pivotal role in most associated diseases. Therefore, this review summarizes currently available literature with special emphasis on the development, anatomy and function of the peritoneal vasculature. Pathological processes are described to illustrate physiological and pathophysiological characteristics of the peritoneum.

Translational and pharmacological principles of hyperthermic intraperitoneal chemotherapy for ovarian cancer.

The long-term survival of advanced-stage ovarian cancer patients remains poor, despite extensive cytoreductive surgery, chemotherapy, and the recent addition of poly (ADP-ribose) polymerase inhibitors (PARPi). Hyperthermic intraperitoneal chemotherapy (HIPEC) has shown survival benefit by specifically targeting peritoneal metastases, the primary site of disease recurrence. Different aspects of how HIPEC exerts its effect remain poorly understood. Improved understanding of the effects of hyperthermia on ovarian cancer cells, the synergy of hyperthermia with intraperitoneal chemotherapy, and the pharmacological and pharmacokinetic properties of intraperitoneally administered cisplatin may help identify ways to optimize the efficacy of HIPEC. This review provides an overview of these translational and pharmacological principles of HIPEC and aims to expose knowledge gaps that may direct further research to optimize the HIPEC procedure and ultimately improve survival for women with advanced ovarian cancer.

Poor perfusion of the microvasculature in peritoneal metastases of ovarian cancer.

Most women with epithelial ovarian cancer (EOC) suffer from peritoneal carcinomatosis upon first clinical presentation. Extensive peritoneal carcinomatosis has a poor prognosis and its pathophysiology is not well understood. Although treatment with systemic intravenous chemotherapy is often initially successful, peritoneal recurrences occur regularly. We hypothesized that insufficient or poorly-perfused microvasculature may impair the therapeutic efficacy of systemic intravenous chemotherapy but may also limit expansive and invasive growth characteristic of peritoneal EOC metastases. In 23 patients with advanced EOC or suspicion thereof, we determined the angioarchitecture and perfusion of the microvasculature in peritoneum and in peritoneal metastases using incident dark field (IDF) imaging. Additionally, we performed immunohistochemical analysis and 3-dimensional (3D) whole tumor imaging using light sheet fluorescence microscopy of IDF-imaged tissue sites. In all metastases, microvasculature was present but the angioarchitecture was chaotic and the vessel density and perfusion of vessels was significantly lower than in unaffected peritoneum. Immunohistochemical analysis showed expression of vascular endothelial growth factor and hypoxia inducible factor 1α, and 3D imaging demonstrated vascular continuity between metastases and the vascular network of the peritoneum beneath the elastic lamina of the peritoneum. We conclude that perfusion of the microvasculature within metastases is limited, which may cause hypoxia, affect the behavior of EOC metastases on the peritoneum and limit the response of EOC metastases to systemic treatment.

Serum Concentration of Anti-TNF Antibodies, Adverse Effects and Quality of Life in Patients with Inflammatory Bowel Disease in Remission on Maintenance Treatment.

BACKGROUND AND AIMS: High serum concentrations of infliximab [IFX] and adalimumab [ADA] may be associated with adverse effects in patients with inflammatory bowel disease [IBD]. We aimed to investigate whether high anti-tumour necrosis factor [TNF] trough levels [TLs] were associated with toxicity and impaired quality of life [QoL]. METHODS: We conducted a prospective cohort study in IBD patients in clinical and biochemical remission on IFX or ADA maintenance therapy. Trough serum concentrations and antidrug antibodies were measured in addition to biochemical markers of inflammation in serum and stool to confirm quiescent disease. QoL was assessed using the Inflammatory Bowel Disease Questionnaire and 36-item short form]. Side effects such as fatigue and arthralgia were measured with a visual analogue score [VAS]. Skin toxicity was reported with a European Organization for Research and Treatment of Cancer-derived score. RESULTS: In all, 252 IBD patients on maintenance anti-TNF therapy were screened, of whom 95 [73 with Crohn's disease, 22 with ulcerative colitis; 72 on IFX, 23 on ADA] were in clinical and biochemical remission and were included. Median TLs were 5.5 µg/ml and 6.6 µg/ml for IFX and ADA, respectively. Patients with anti-TNF TLs above median had lower IBDQ scores than patients with lower TLs [IBDQ 176 vs 187, p = 0.02], particularly regarding systemic symptoms and emotional status. A trend towards lower SF-36 and higher fatigue scores was observed in the higher anti-TNF TL group. Skin and arthralgia scores were not significantly different between the groups. CONCLUSIONS: IBD patients with higher anti-TNF serum concentrations had significantly lower disease-specific QoL. Fatigue, arthralgia, and skin lesions do not occur more often in these patients. These data are reassuring that high serum concentrations of anti-TNF antibodies are not toxic.