Compression versus hand-sewn and stapled anastomosis in colorectal surgery: a systematic review and meta-analysis of randomized controlled trials.

Anastomotic leaks are a feared complication of colorectal resections and novel techniques that have the potential to decrease them are still sought. This study aimed to compare the anastomotic leak rates in patients undergoing compression anastomoses versus hand-sewn or stapled anastomoses. Randomized controlled trials (RCTs) comparing outcomes of compression versus conventional (hand-sewn and stapled) colorectal anastomosis were collected from MEDLINE, Embase and the Cochrane Library. The quality of the RCTs and the potential risk of bias were assessed. Pooled odds ratios (OR) were calculated for categorical outcomes and weighted mean differences for continuous data. Ten RCTs were included, comprising 1969 patients (752 sutured, 225 stapled, and 992 compression anastomoses). Most used the biofragmentable anastomotic ring. There was no significant difference between the two groups in terms of anastomotic leak rates (OR 0.80, 95 % confidence interval (CI) 0.47, 1.37; p = 0.42), stricture (OR 0.54: 95 % CI 0.18, 1.64; p = 0.28) or mortality (OR 0.70; 95 % CI 0.39, 1.26; p = 0.24). Compression anastomosis was associated with an earlier return of bowel function: 1.02 (95 % CI 1.37, 0.66) days earlier (p < 0.001) and a shorter postoperative stay; 1.13 (95 % CI 1.52, 0.74) days shorter (p < 0.001), but significant heterogeneity among studies was observed. There was an increased risk of postoperative bowel obstruction in the compression group (OR 1.87; 95 % CI 1.07, 3.26; p = 0.03). There was no significant difference in wound-related and general complications, or length of surgery. Compression devices do not appear to provide an advantage over conventional techniques in fashioning colorectal anastomoses and are associated with an increased risk of bowel obstruction.

Hypoxia stimulates angiogenesis and a metabolic switch in human parathyroid adenoma cells.

Hypoxia, a primary stimulus for angiogenesis, is important for tumour proliferation and survival. The effects of hypoxia on parathyroid tumour cells, which may also be important for parathyroid autotransplantation in patients, are, however, unknown. We, therefore, assessed the effects of hypoxia on gene expression in parathyroid adenoma (PA) cells from patients with primary hyperparathyroidism. Cell suspensions from human PAs were cultured under normoxic or hypoxic conditions and then subjected to cDNA expression analysis. In total, 549 genes were significantly upregulated and 873 significantly downregulated. The most highly upregulated genes (carbonic anhydrase 9 (CA9), Solute carrier family 2A1 (SLC2A1) and hypoxia-inducible lipid droplet-associated protein (HIG2)) had known involvement in hypoxia responses. Dysregulation of oxidative phosphorylation and glycolysis pathway genes were also observed, consistent with data indicating that cells shift metabolic strategy of ATP production in hypoxic conditions and that tumour cells predominantly utilise anaerobic glycolysis for energy production. Proliferation- and angiogenesis-associated genes linked with growth factor signalling, such as mitogen-activated protein kinase kinase 1 (MAP2K1), Jun proto-oncogene (JUN) and ETS proto-oncogene 1 (ETS1), were increased, however, Ras association domain family member 1 (RASSF1), an inhibitor of proliferation was also upregulated, indicating these pathways are unlikely to be biased towards proliferation. Overall, there appeared to be a shift in growth factor signalling pathways from Jak-Stat and Ras signaling to extracellular signal-regulated kinases (ERKs) and hypoxia-inducible factor (HIF)-1α signalling. Thus, our data demonstrate that PAs, under hypoxic conditions, promote the expression of genes known to stimulate angiogenesis, as well as undergoing a metabolic switch.