PurposeAnastomotic leakage is a serious complication after colorectal surgery. Pre- and intraoperative factors may contribute to failure of colorectal anastomosis. In this study we have tried to determine risk factors for anastomotic leakage, with special emphasis on intraoperative blood pressure changes.MethodsDuring a 24-month period, patients receiving a colorectal anastomosis were prospectively evaluated. For each patient preoperative characteristics, intraoperative adverse events and surgical outcome data were collected. Blood pressure changes were calculated as a relative decrease (>25% and >40%) from preoperative baseline values.ResultsDuring the study period, 285 patients underwent colorectal surgery with an anastomosis. Fifteen patients developed an anastomotic leakage (5.3%). All patients who developed a leakage had a left-sided procedure (P < 0.001). When blood loss was more than 250 mL (P = 0.003) or an intraoperative adverse event occurred (P = 0.050), the risk for developing an anastomotic leakage was significantly increased. A preoperative high diastolic blood pressure of ≥90 mmHg (P = 0.008) and severe intraoperative hypotension [>40% decrease in diastolic blood pressure (P = 0.049)] were identified as univariate risk factors for anastomotic leakage.ConclusionsThe development of an anastomotic leakage after colorectal surgery is related to surgical, patient and anaesthetic risk factors. A high preoperative diastolic blood pressure and profound intraoperative hypotension combined with complex surgery, marked by a blood loss of ≥250 mL and the occurrence of intraoperative adverse events, is associated with an increased risk of developing anastomotic leakage.

The purpose of this study was to investigate whether combined inhibition of neuronal and inducible nitric oxide synthase (NOS) by 2-iminobiotin, free radical scavenging by allopurinol, and non-protein-bound iron chelation with deferoxamine improved cerebral oxygenation, electrocortical brain activity, and brain energy status during the first 24 h after hypoxia-ischemia (HI) in the newborn piglet. Forty-three newborn piglets were subjected to 1 h of severe HI by occluding both carotid arteries and phosphorous magnetic resonance spectroscopy ((31)P-MRS)-guided hypoxia, whereas five served as sham-operated controls. Upon reperfusion, piglets received vehicle (n=12), 2-iminobiotin (n=11), allopurinol (n=10), or deferoxamine (n=10). Cerebral oxygenation was recorded with near-infrared spectrophotometry (NIRS), electrocortical brain activity was assessed with amplitude-integrated EEG (aEEG), and cerebral energy status with (31)P-MRS. The oxygenated hemoglobin (HbO(2)) and total hemoglobin (tHb) were significantly increased in vehicle-treated piglets compared with 2-iminobiotin-treated and deferoxamine-treated piglets. No change in deoxygenated Hb (HHb) was demonstrated over time. The aEEG was significantly preserved in 2-iminobiotin- and deferoxamine-treated piglets compared with vehicle-treated piglets. Allopurinol treatment was not as effective as 2-iminobiotin treatment after HI. Phosphocreatine/inorganic phosphate ratios (PCr/P(i)) were significantly decreased for vehicle-treated piglets at 24 h post-HI, whereas 2-iminobiotin, allopurinol, and deferoxamine prevented the development of secondary energy failure. We speculate that the beneficial effects, especially of 2-iminobiotin, but also of deferoxamine, are due to reduced peroxynitrite-mediated oxidation.

Perinatal asphyxia models are necessary to obtain knowledge of the pathophysiology of hypoxia-ischaemia (HI) and to test potential neuroprotective strategies. The present study was performed in newborn piglets to obtain information about simultaneous changes in cerebral oxygenation and haemodynamics and electrocortical brain activity during a 60-min period of HI and up to 2 h of reperfusion using near infrared spectrophotometry (NIRS) and the amplitude-integrated EEG (aEEG). HI was induced by occluding both carotid arteries and decreasing the fraction of inspired oxygen (FiO(2)) to 0.08-0.12 for 60 min. The mean arterial blood pressure (MABP) and heart rate increased, the oxygenated haemoglobin (O(2)Hb) decreased, and the deoxygenated haemoglobin (HHb) increased, but total haemoglobin (tHb) remained stable during the 60-min HI period. The regional oxygen saturation (rSO(2)) was significantly decreased during the whole HI period, as was the electrocortical brain activity. Upon reperfusion and reoxygenation, the MABP normalised to baseline values but the heart rate remained increased. O(2)Hb and HHb recovered to baseline values and tHb remained unchanged. As indicated by the unchanged tHb values during the HI period, it was suggested that compensatory cerebral perfusion occurred during this period, probably via the vertebrobasilar arterial system. Furthermore, in this model a clear hyperperfusion period directly upon reperfusion and reoxygenation is not present. rSO(2) showed a quick recovery to baseline values, but the aEEG-measured electrocortical brain activity remained reduced following HI. In conclusion, the rSO(2) and aEEG showed a different time profile following perinatal asphyxia. The stable tHb during HI and reperfusion in this model differs from observations in human neonates.