Evita Zoucas

Impairment of Primary Hemostasis and Platelet Function after Alcohol Ingestion in Man

The effect of alcohol ingestion on primary hemostasis was investigated in fasting healthy humans. Primary hemostasis was measured with the template bleeding time and platelet aggregation assayed with the turbidometric method. Blood was collected to study coagulation and fibrinolysis. 1 h after ingestion of 2 ml/kg body weight of 40% alcohol the plasma alcohol concentration was 19.3 +/- 1.6 mmol/l. At this time there was a significant prolongation of the bleeding time accompanied by an impairment of platelet responsiveness to both collagen and ADP. A prolongation of the bleeding time and impairment of platelet function was also found 2 h after alcohol ingestion. Ingestion of this amount of alcohol did not affect parameters of coagulation or fibrinolysis. The data indicate that primary hemostasis is impaired in man after ingestion of moderate amounts of alcohol. This may explain the favorable effect of moderate alcohol consumption on ischemic heart disease but indicates an increased risk for patients with bleeding.

Bilateral thoracoscopic splanchnicectomy: effects on pancreatic pain and function.

OBJECTIVE To evaluate prospectively the effect of bilateral thoracoscopic splanchnicectomy on pancreatic pain and function. SUMMARY BACKGROUND DATA Severe pain is often the dominant symptom in pancreatic disease, despite a wide variety of methods used for symptom relief. Refinement of thoracoscopic technique has led to the introduction of thoracoscopic splanchnicectomy in the treatment of pancreatic pain. METHODS Forty-four patients, 23 with pancreatic cancer and 21 with chronic pancreatitis, were included in the study and underwent bilateral thoracoscopic splanchnicectomy. Effects on pain (visual analogue scale) and pancreatic function (standard secretin test, basal serum glucose, plasma insulin, and C-peptide) were measured. RESULTS Four patients (9%) required thoracotomy because of bleeding. There were no procedure-related deaths. The mean duration of follow-up was 3 months for cancer and 43 months for pancreatitis. Pain relief was evident in the first postoperative week and was sustained during follow-up, the average pain score being reduced by 50%. All patients showed a decrease in consumption of analgesics. Neither endocrine nor exocrine function was adversely affected by the procedure. CONCLUSIONS Bilateral thoracoscopic splanchnicectomy is beneficial in the treatment of pancreatic pain and is not associated with deterioration of pancreatic function.

Insertion of Self-Expandable Nitinol Stents Without Previous Balloon Angioplasty Reduces Restenosis Compared with PTA Prior to Stenting

Purpose: To compare the development of intimal hyperplasia after deployment of a self-expanding nitinol stent with and without previous percutaneous transluminal balloon angioplasty (PTA), with the results after PTA alone. Methods: In nine healthy pigs, the iliac arteries were divided into three groups: group 1 (n = 6 arteries) was treated with PTA; group 2 n = 6) with insertion of self-expanding stents after PTA; and group 3 (n = 6) with stent insertion without previous PTA. After 8 weeks the vessels were examined with intravascular ultrasonography, histologic examination and morphometric analysis. Results: Although the injury index in group 1 (0.17 ± 0.57) was lower (p <0.05) than in group 2 (0.26 ± 0.06) and group 3 (0.26 ± 0.08), PTA-treated arteries showed significantly (p <0.05) reduced mean luminal gain (0.53 ± 2.84) compared with arteries treated with PTA prior to stenting (2.58 ± 1.38) and compared with stenting alone (4.65 ± 5.34). Stenting after PTA resulted in a higher (p <0.05) restenosis index (2.63 ± 1.06) compared with stenting without PTA (1.35 ± 0.59). Group 2 also had a significantly thicker intima p <0.05) and 83% and 74% higher intima/media ratio (p <0.05) compared with groups 1 and 3, respectively. Conclusion: Insertion of a self-expandable nitinol stent without previous PTA results in less intimal hyperplasia than if PTA is performed prior to stenting, suggesting that direct stenting can be used in angioplasty sessions with a favorable outcome.

Differences in Endothelial Injury After Balloon Angioplasty, Insertion of Balloon-Expanded Stents or Release of Self-Expanding Stents: An Electron Microscopic Experimental Study

AbstractPurpose: To evaluate which of six different commonly available stents inserted into an artery without percutaneous transluminal angioplasty (PTA) causes the least endothelial damage. To compare the degree of endothelial injury after insertion of such a stent with injury caused by PTA. Methods: Twelve healthy pigs were used in the experiments. In the first part of the study six different types of stents were inserted into the common iliac arteries. In the second part of the study self-expanding stents with large spaces between the wires were used. PTA was performed in the contralateral iliac artery. The pigs were killed immediately after the procedure and resected specimens examined after fixation, using scanning electron microscopy. Results: All procedures but two were accomplished successfully. More endothelium was preserved after insertion of self-expanding stents with large spaces between the wires, compared with stents with small spaces and balloon-expanded stents. After insertion of self-expanding stents with large spaces, 50.1% ± 16.4% of the endothelium remained intact, compared with only 5.6% ± 7.7% after PTA. The difference was statistically significant (p < 0.001). Conclusion: Self-expanding stents with large spaces between the wires, inserted without PTA, cause less damage to the endothelium than other stents and significantly less damage than PTA.

COMPARATIVE-EVALUATION OF LOCAL HEMOSTATIC AGENTS IN EXPERIMENTAL LIVER TRAUMA - A STUDY IN THE RAT

The efficacy of gelatin foam, oxidized regenerated cellulose, collagen fleece, and microcrystalline collagen as hemostatic agents was tested after standardized liver trauma in the rat. Experiments were divided into two series. In the first series all the above local hemostatic agents were tested on normal animals. Animals in which surgical gauze was applied to the traumatized surface served as controls. Nontreated animals bled profusely. Microcrystalline collagen and collagen fleece were more effective than gauze. In the second series collagen preparations were tested on animals with hemostatic disorders caused by administration of acetylsalicylic acid, ethanol intoxication, or infusion of bensylpenicillin. Collagen preparations were as effective as gauze in diminishing bleeding time and blood loss after liver trauma.

Thoracoscopic Splanchnicectomy for Chronic, Severe Pancreatic Pain

Fourteen patients with pancreatic cancer, 2 with cancer of the papilla of Vater, and 14 with chronic pancreatitis were operated on with bilateral thoracoscopic splanchnicectomy caused by severe chronic pain. The median follow-up time was 13 months. Twenty patients were followed up for 3 months and 14 for at least 6 months. The surgical results were evaluated prospectively, both with visual analogue scale (VAS) and with documentation of the consumption of analgesics at elective follow-up after 1 week and 1, 3, 6, and 12 months postoperatively. All 30 patients stated that the characteristics of their pain had changed at recovery from anaesthesia, but only 6 of them reported immediate complete pain relief. All but 1 of the 14 patients with chronic pancreatitis had clearly reduced pain as evaluated by VAS 1 month after the operation, and this beneficial effect remained for the whole study period. Furthermore, the need for analgesics decreased. Also, in the 16 patients with cancer, there was on average a marked relief of pain from 1 week and onwards. The 6 cancer patients with survival more than 3 months had reduced pain for the remaining period of their lives. It seems that the final pain relief is persistent as is the reduced consumption of analgesics. There was no correlation between the number of cut nerves and pain relief as evaluated by VAS. Three patients were reoperated on for intrathoracic bleeding the evening after the operation, and one had transient pain located to one of the port sites. Otherwise, there were no postoperative complications. The operation time was short and the length of hospital stay in most patients was 24 hours or less. It was concluded that thoracoscopic splanchnicectomy appears to be a promising and relatively simple treatment for severe chronic pancreatic pain. Further studies are needed to establish its role in the management of intractable pancreatic pain.

Proliferative response in smooth muscle cells after angioplasty or insertion of self-expanding stents : An experimental study in pigs

Purpose: Evaluation of the early proliferative reaction of smooth muscle cells (SMC) in the media of the artery following percutaneous transluminal angioplasty (PTA), compared with the reaction on insertion of self-expandable stents. Material and Methods: In 6 healthy pigs, one iliac artery was overdilated with an 8-mm diameter angioplasty balloon. A self-expanding Nitinol stent, OD 8 mm, was inserted into the contralateral iliac artery without previous dilatation. The nuclei of the proliferating SMC in the media of the artery were labelled by intravenous administration of 5-bromo-2-deoxy-uridine and cells in S-phase counted 24 h after the procedure. Results: The mean number of proliferating nuclei of the SMC increased significantly more after PTA (p<0.05) than after the insertion of a stent. Conclusion: Early proliferative reaction of the SMC is more pronounced after PTA than after insertion of the self-expanding stent.

Circulatory and ventilatory effects of intermittent nitric oxide inhalation during porcine endotoxemia.

The effects of intermittent inhalation of 57 ppm nitric oxide (NO) were studied in eight anesthetized, ventilated pigs given a continuous infusion of Escherichia coli endotoxin. Seven animals served as controls. By administering NO synchronized with inspiration and close to the orotracheal tube, measurable amounts of the toxic metabolite, NO2, in the inspiratory gas mixture were avoided. No direct systemic effects of NO inhalation were seen, but through counteracting pulmonary vasoconstriction, a fall in cardiac output was delayed. Nitric oxide effectively attenuated the initial peak rise in mean pulmonary artery pressure and resistance, both returning to control levels after cessation of NO. These effects were reproduced during later phases of endotoxemia, giving further proof to the role of gaseous NO as a selective pulmonary vasodilator. Nitric oxide diminished pulmonary shunting, but unimpaired oxygenation was preserved only during the first inhalation period. Leukocyte counts decreased drastically and platelet aggregation was enhanced, but after 1.5 hours of endotoxin infusion, platelet hyperaggregation was maintained in the NO group while it decreased in the control group.

Effect of Acute Ethanol Intoxication on Primary Haemostasis, Coagulation Factors and Fibrinolytic Activity

The effect of ethanol intoxication on haemostasis was studied by transection of mesenteric microvessels and liver resection in the rat. Plasma concentrations of alcohol were within the range of those found in ethanol intoxication in man. Bleeding time and blood loss were increased 1 h after ethanol administration, regardless of the utilized technique. A significant positive correlation existed between bleeding time following liver resection and bleeding time after simultaneous transection of a mesenteric arteriole and venule. Coagulation mechanisms, assayed by whole blood clotting time, APT time, one-stage prothrombin time, recalcification time, thrombin time, Owrens P & P test and determination of plasma factor V and fibrinogen levels, were not significantly changed in ethanol-intoxicated animals. Administration of alcohol did not affect fibrinolytic activity, while it inhibited significantly ADP and collagen-induced platelet aggregation in the rat.

Hospital costs associated with surgical morbidity after elective colorectal procedures: a retrospective observational cohort study in 530 patients

BackgroundPostoperative complications contribute to morbidity and mortality. This study assessed the impact of surgical complications on healthcare resource utilization for patients undergoing elective colorectal procedures.MethodData were obtained on 530 consecutive colorectal operations performed from January 2010 to January 2011. Patient demographics, type of procedure, surgical complications classified as Clavien 1–5, length of stay, 60-day readmission rate, and hospital costs were recorded.ResultsSeventy-five percent of the operations were associated with malignancy, and 26% were pelvic procedures. Thirty-five percent of the patients developed at least one complication, 21% of the complications did not require intervention. The readmission rate was 7.4%. Nine patients died during 60-day post discharge follow up.Median length of stay was 9 (3–34) days in uncomplicated and 16 (4–205) days in complicated cases. Occurrence of any complication at index admission increased total hospital costs 2.1-fold (EUR 25,680 vs. EUR 12,405), with the largest cost differential attributed to wound dehiscence and/or suture line failure requiring reoperation. These increases were primarily due to prolonged hospitalization and ICU expenditures. Readmission resulted in a further increase to an average cost of EUR 12,585 per re-admitted patient.Multivariate analysis showed that BMI > 25, obesity, operation complexity and surgeon significantly affected the risk for complication. Also, hospital costs were significantly increased by any postoperative complications, reoperations, high complexity of surgical procedures and high comorbidity index.ConclusionsReducing morbidity after colorectal procedures improves quality of care and patient safety, and may also substantially reduce hospital costs and increase the efficiency of resource utilization.