Krystyn Sosada

Sex-dependent differences in rheological properties and the relation of blood viscosity to erythrocyte aggregation indices among morbidly obese patients

Some studies indicate that obesity is associated with rheological disturbances. Because there are usually sex differences in the type of obesity we decided to evaluate rheological differences between male and female obese patients. We studied 18 morbidly obese men, mean age 43.66 +/- 11.32 years, mean body mass index (BMI) 49.82 +/- 6.03 kg/m2 and 20 obese females, mean age 40.6 +/- 11.86 years, mean BMI 47.41 +/- 8.81 kg/m2. Blood and plasma viscosity measurements were performed using a cone-plate viscometer (Brookfield DV-II). Erythrocyte elongation and red blood cell (RBC) aggregation were measured using the Laser-assisted Optical Rotational Cell Analyser (LORCA). Whole blood viscosity and RBC deformability expressed by the elongation index were significantly higher in obese men. We did not observe differences in plasma viscosity, corrected blood viscosity and aggregation parameters among the obese population. Blood viscosity correlated with selected RBC aggregation indices. We conclude that morbidly obese patients presented sex-dependent differences in some rheological properties. This study indicates a relation between erythrocyte aggregation indices and blood viscosity in obese populations.

Association between hemorheological alteration and clinical diagnosis of metabolic syndrome among patients qualified for bariatric surgery

This study presents the association between metabolic syndrome and hemorheological parameters among obese patients qualified for bariatric surgery. We studied 73 morbidly obese patients who were qualified for bariatric surgery. Blood and plasma viscosity measurements were performed using a cone-plate viscometer (Brookfield DV-II). RBC aggregation was measured using the Laser-assisted Optical Rotational Cell Analyser (LORCA). The following parameters for the aggregation process were estimated: aggregation index (AI), amplitude (AMP), aggregation half-time (t1/2), threshold shear rate (γthr), the fast (Tfast) and the slow (Tslow) component. Metabolic syndrome was defined according to the Adult Treatment Panel III and International Diabetes Federation criteria. The obese presented differences in all rheological properties compared to control, regardless of clinical diagnosis of metabolic syndrome, except that whole blood viscosity was higher only in the obese metabolic syndrome group. No differences among the obese with and without metabolic syndrome were observed except in hematocrit. Whole blood viscosity and corrected blood viscosity correlated positively with WHR and BMI. AI, γthr, Tslow correlated positively with BMI, WHR, total cholesterol level and low-density lipoproteins. Negative correlation presented t1/2 with BMI, WHR, fibrinogen, total cholesterol level and low-density lipoproteins. The study showed that morbid obesity is associated with hemorheological disturbances independently of clinical diagnosis of metabolic syndrome.

Shear stress and flow dynamics of the femoral vein among obese patients who qualify for bariatric surgery

The aim of this study was to evaluate the effects of obesity on wall shear stress and its relationship to erythrocyte aggregation. We studied 35 morbidly obese patients who were qualified for bariatric surgery. The control group consisted of 20 non-obese people. Blood rheological measurements were performed using the Laser-assisted Optical Rotational Cell Analyzer (Mechatronics, the Netherlands) and a cone-plate viscometer (Brookfield DV-II). The venous flow dynamics were assessed using a duplex ultrasound. The shear rate was estimated from the measured blood flow velocity and the diameter of the femoral vein. Venous wall shear stress was calculated from the whole blood viscosity and the shear rate. The shear rate (P < 0.005) and the venous wall shear stress (P < 0.05) were significantly lower in obese patients compared with the controls. The aggregation index (P < 0.001), syllectogram amplitude - AMP (P < 0.05) and Tslow (P < 0.001) were significantly higher in the obese patients; the aggregation half-time (P < 0.001) and Tfast (P < 0.001) were decreased compared with the control group. Multivariate regression analyses found waist circumference (β -0.31, P < 0.05), thigh circumference (β 0.33, P < 0.05) and Tslow (β -0.47, P < 0.005) to be variables that independently influenced the shear rate. Nevertheless, the AMP (β 0.34, P < 0.05) and Tslow (β -0.47, P < 0.01) were independent predictors that influenced the wall shear stress. This study indicates that there is a relationship between wall shear stress in the femoral vein and the rheological impairment of the RBC among obese patients, but further studies are necessary to confirm this suggestion.

Literature review of non-operative management of patients with blunt splenic injury: impact of splenic artery embolization

Splenic injuries constitute the most common injuries accompanying blunt abdominal traumas. Non-operative treatment is currently the standard for treating hemodynamically stable patients with blunt splenic injuries. The introduction of splenic angiography has increased the possibility of non-operative treatment for patients who, in the past, would have qualified for surgery. This cohort includes mainly patients with severe splenic injuries and with active bleeding. The results have indicated that applying splenic angioembolization reduces the frequency of non-operative treatment failure, especially in severe splenic injuries; however, it is still necessary to perform prospective, randomized clinical investigations.

Fast track in large intestine surgery – review of randomized clinical trials

Fast track surgery is a specific perioperative procedure. Its aim is to reduce the number of complications, to improve the comfort and satisfaction of treated patients and to shorten the time of their hospital stay. In this paper we present randomized clinical trials relating to fast track surgery including patients after colorectal resection.

Mortality and anastomotic leakage after anterior resection for rectal cancer.

BACKGROUND/AIMS The aim of the study was to analyze the mortality and symptomatic anastomotic leak following stapled anastomosis after anterior resection for rectal cancer. METHODOLOGY We analyzed retrospectively 161 patients subjected to elective anterior resection of the rectum. There were 102 (63.3%) men and 59 (37.7%) women. The patients were divided into two groups according to tumor location: group I - 129 (80.1%) patients with tumor located >6 cm from the anal verge and group II - 32 (19.9%) patients with tumor located =6 cm. RESULTS Anastomotic leak was found in 5 (3.1%) patients, three (2.3%) from group I and two (6.2%) from group II (p<0.26). Anastomotic leak was found more often in patients with renal failure (p<0.0023) and in those who had undergone RBC concentrate transfusion (p<0.0045). Seven (4.3%) patients died in the postoperative period. Deaths occurred more frequently in patients with valvular heart disease (p<0.00002), renal failure (p<0.0047) and in those given concentrates of RBC (p<0.045). CONCLUSIONS Incidence of postoperative surgical complications after resection for rectal cancer is not high and is acceptable; however, there is an increased risk of leakage after low anterior resection. Renal failure as well as RBC concentrate transfusion have an influence on mortality and anastomotic leak.

The role of laparoscopy in abdominal trauma - review of the literature.

The necessity of urgent explorative laparotomy as a standard procedure in the treatment of abdominal penetrating wounds is controversial. Mandatory surgical intervention for penetrating abdominal trauma yields a high rate of negative laparotomies in the absence of visceral injuries. Laparoscopy is an alternative diagnostic procedure inspecting the peritoneum for signs of perforation and excluding significant intra-abdominal injuries. Following current guidelines, diagnostic laparoscopy should be used with caution only in selected cases due to the limited amount of reliable data confirming the effectiveness of such treatment. We present a review of the literature analysing the role of diagnostic laparoscopy in abdominal trauma.

The effects of obesity on CD47 expression in erythrocytes

To investigate the effects of obesity on CD47, phosphatidylserine (PS) exposure, and Caspase‐8 and Caspase‐3 activities in erythrocytes.

The impacts of super obesity versus morbid obesity on red blood cell aggregation and deformability among patients qualified for bariatric surgery.

The aim of this study was to evaluate the effects of the obesity degree on red blood cell aggregation and deformability. We studied 56 obese patients before weight loss surgery who were divided into two groups: morbid obesity and super obesity. The aggregation and deformability of RBCs were evaluated using a Laser-assisted Optical Rotational Cell Analyzer (Mechatronics, the Netherlands). The following parameters specific to the aggregation process were estimated: aggregation index (AI), aggregation half-time (t1/2) and threshold shear rate (γthr). RBC deformability was expressed as erythrocyte elongation (EI), which was measured at 18.49 Pa and 30.2 Pa shear stresses. Super obese patients presented significantly higher AI (P < 0.05) and γthr (P < 0.05) and significantly lower t1/2 (P < 0.05) compared with morbidly obese individuals. Multivariate analyses showed that fibrinogen (β 0.46, P < 0.01 and β 0.98, P < 0.01) and hematocrit (β 0.38, P < 0.05 and β 1.01, P < 0.01) independently predicted the AI in morbidly obese and super obese patients. Fibrinogen (β -0.4, P < 0.05 and β -0.91, P < 0.05) and hematocrit (β -0.38, P < 0.05 and β -1.11, P < 0.01) were also independent predictors of the t1/2 in both obese groups. The triglyceride level (β 0.32, P < 0.05) was an independent predictor of the t1/2 in the morbidly obese group. No differences in EI were observed between obese subjects. Multivariate analyses showed that the triglyceride level independently predicted EI at 18.49 Pa (β -0.42, P < 0.05 and β -0.53, P < 0.05) and 30.2 Pa (β -0.44, P < 0.01 and β -0.49, P < 0.05) in both obese groups. This study indicated that the obesity degree of patients who qualify for bariatric surgery affects RBC aggregation properties, but it does not indicate the reasons for this difference. Further studies are needed to determine factors associated with hyperaggregation in super obesity.

The effects of weight loss surgery on blood rheology in severely obese patients

BACKGROUND The effects of dieting on blood rheology in obese individuals suggest that improving the rheologic profiles depends on the amount of weight lost and its long-term maintenance. The aim of this study was to evaluate the effects of weight loss after surgery on blood rheology at 12-month follow-up. METHODS We studied 38 obese patients who underwent laparoscopic weight loss surgery, 22 of whom had sleeve gastrectomy (SG) and 16 of whom had gastric banding (LAGB). We evaluated rheologic parameters such as blood viscosity, plasma viscosity, and erythrocyte deformability (as measured by elongation index [EI]) preoperatively and 12 months after surgery. RESULTS Whole blood viscosity at 150 s(-1) shear rate (P<.01) and 300 s(-1) shear rate (P<.05), blood viscosity corrected to a standard hematocrit at both shear rates (P<.0005 and P<.005, respectively), and plasma viscosity (P<.005) were significantly reduced after surgery. EI evaluated at different shear stresses (18.49-60.03 Pa) decreased (P<.005) 12 months after surgery. There were significantly decreased EI and blood viscosity corrected to a standard hematocrit after SG (P<.005 and P<.05) and LAGB (P = .0621 and P<.05), but plasma viscosity significantly decreased only after SG (P<.005). Blood viscosity at both shear rates correlated with plasma viscosity (r = .51, P<.005 and r = .5, P<.005). Plasma viscosity correlated positively with body mass index (r = .57; P<.0005) and negatively with percentage of excess weight lost (r = -.56; P< .005). CONCLUSIONS This study found that weight loss after bariatric surgery induced improvement in blood rheology in obese patients at 12 months after surgery. The increased red blood cell rigidity after surgery requires further study because the physiologic importance of this change has not yet been established.