Peristaltic Transport of Prandtl-Eyring Liquid in a Convectively Heated Curved Channel.

Here peristaltic activity for flow of a Prandtl-Eyring material is modeled and analyzed for curved geometry. Heat transfer analysis is studied using more generalized convective conditions. The channel walls satisfy complaint walls properties. Viscous dissipation in the thermal equation accounted. Unlike the previous studies is for uniform magnetic field on this topic, the radial applied magnetic field has been utilized in the problems development. Solutions for stream function (ψ), velocity (u), and temperature (θ) for small parameter ß have been derived. The salient features of heat transfer coefficient Z and trapping are also discussed for various parameters of interest including magnetic field, curvature, material parameters of fluid, Brinkman, Biot and compliant wall properties. Main observations of present communication have been included in the conclusion section.

Realistic Survival Outcomes After Vasopressor Use in the Intensive Care Unit.

AIM: Patients in the intensive care unit (ICU) have significantly increased mortality rates. Frequently, clinicians are called upon to help families make decisions regarding aggressiveness of care. Having a realistic expectation of outcome is critical for these discussions. This article looked at survival and outcomes following initiation of vasopressors. METHODS: All patients admitted to the ICU between January and June 2011were included. Patients were classified into those who had been started on vasopressors (VP+) and those who had not (VP-). Outcomes of these groups including survival were calculated and compared. RESULTS: A total of 1023 patients were included: 169 in the VP+ group and 854 in the VP- group. The survival rate in the VP+ group was 29.6% compared to 92.0% in the VP- group. This was both clinically and statistically significant (P < .001). CONCLUSION: Patients started on vasopressors in the ICU have very poor outcomes. Being able to quantify this accurately is important to clinicians having discussions with family members.

Carcinoma in situ in a 7 mm gallbladder polyp: Time to change current practice?

Detection of polypoid lesions of the gallbladder is increasing in conjunction with better imaging modalities. Accepted management of these lesions depends on their size and symptomatology. Polyps that are symptomatic and/or greater than 10 mm are generally removed, while smaller, asymptomatic polyps simply monitored. Here, a case of carcinoma-in-situ is presented in a 7 mm gallbladder polyp. A 25-year-old woman, who had undergone a routine cholecystectomy, was found to have an incidental 7 mm polyp containing carcinoma in situ. She had few to no risk factors to alert to her condition. There are few reported cases of cancer transformation in gallbladder polyps smaller than 10 mm reported in the literature. The overwhelming consensus, barring significant risk factors for cancer being present, is that such lesions should be monitored until they become symptomatic or develop signs suspicious for malignancy. In our patient's case this could have led to the possibility of missing a neoplastic lesion, which could then have gone on to develop invasive cancer. As gallbladder carcinoma is an aggressive cancer, this may have led to a tragic outcome.

Single-Site Robotic Cholecystectomy: The Timeline of Progress.

AIM: To investigate the learning curve and perioperative outcomes of single-site robotic cholecystectomy during the first 102 cases by a single surgeon. MATERIALS AND METHODS: A retrospective review of a prospectively maintained database was performed on the first 102 cases of single-site robotic cholecystectomy. Patients were divided into five chronological groups based on the date of surgery, with 20 patients in each group except the 5th group which had 22 patients. The groups were compared by docking time, robotic dissection time, and overall surgery time. A P value of 0.05 was used as statistically significant. RESULTS: The female to male ratio was 2:1. The mean age was 51 years (18-87) and the mean BMI was 28.26 (18-41). Overall, 69 % of the patients underwent elective cholecystectomy and 31 % required urgent surgery. In all, 17 % of patients had previous abdominal surgeries. In total, 45 % of procedures were regarded as same day surgery. The total mean length of stay was 1.97 days (0-8). The mean operative time was 110 min (36-265), mean robotic console time 70 min (26-179), and mean docking time 9 min (1-26). The overall conversion rate was 3.9 % and the complication rate was 4 %. The docking time, robotic time, and average operative time were significantly different in the first group as compared to the remaining the five groups (P = 0.001). CONCLUSION: Single-site robotic cholecystectomy is safe in both elective and urgent conditions, and in patients with previous abdominal surgeries. It has a short learning curve.

Sealing of vessels larger than 7 millimeters using Enseal in porcine aorta.

BACKGROUND: The Enseal (Ethicon Endo-Surgery, Blue Ash, Ohio) tissue-sealing device has proven efficacy for ligation of vessels<7 mm in diameter, even with significant supraphysiologic bursting pressures. We aimed to evaluate the safety of Enseal in porcine vessels>7 mm. MATERIALS AND METHODS: The lumbar aortas of pigs that were euthanized for unrelated procedures were harvested. A 5- to 6-cm segment of aorta was sealed using the Enseal device. The opposite end was attached to a pressure-testing device to measure pressures at leak or bursting. The bivariate Pearson correlation was used to determine the relationship between diameter and bursting pressure. One-way analysis of variance was used to determine differences between the groups of vessels on the basis of their diameter. RESULTS: Ninety samples of 5-cm aorta segments were used to assess bursting pressure. The median diameter was 14 mm (range, 7-18) and bursting pressure was 85 mm Hg (range, 24-650). The Pearson test showed a negative correlation between vessel diameter and bursting pressure (P=.25). One-way analysis of variance did not show any significant difference between vessel diameters grouped by size (P=.517), and neither did the Scheffe post hoc test when comparing diameter with bursting pressure; 31% of specimens failed to seal. CONCLUSIONS: Bursting pressures are low and inconsistent after tissue sealing with the Enseal device in porcine vessels>7 mm. These vessels also demonstrated a higher rate of failure to seal. The histologic results of the aorta segments (ie, a low collagen-elastin ratio) may be the cause of the low bursting pressures.

A prospective study of in vivo and ex vivo sealing of the human inferior mesenteric artery using an electrothermal bipolar vessel-sealing device.

BACKGROUND: Mesenteric vascular ligation is a critical step in minimally invasive colorectal surgery. This study assessed the quality of in vivo and ex vivo sealing of the human inferior mesenteric artery (IMA), as well as the relation of IMA stump and bursting pressure. PATIENTS AND METHODS: This was a prospective experimental study in a tertiary-care teaching hospital. In total, 25 patients were included in the study. For the main outcome measures, bursting pressures were measured for each specimen. Ten freshly sealed specimens were histologically assessed for seal quality and lateral thermal damage. RESULTS: We evaluated 54 specimens from 25 patients for bursting pressure, of which 25 were primary sealed vessels (sealed in vivo at surgery) and 29 were secondary sealed vessels (sealed in the laboratory). The mean bursting pressure was 862 mm Hg. The mean diameter was 4 mm (range, 3-5 mm) with a standard deviation of 1 mm. Pearson correlation showed no correlation between diameter and bursting pressure (P=.187) or the length and bursting pressure (P=.247). There was no statistically significant difference in bursting pressures in the four groups of vessels based on length. One calcified vessel had a significantly lower bursting pressure of 89 mm Hg. There was no intraoperative or postoperative bleeding. Ten sealed specimens were sent for histological evaluation, which showed mean lateral thermal damage of 0.57 mm (range, 0-1.75 mm). CONCLUSIONS: The bursting pressure in IMAs sealed with a bipolar device is significantly higher than physiological pressures; thus, the device can be safely used in sealing the vessel during colorectal surgery. Additionally, the length of the vessel stump does not correlate with the bursting pressures. Care needs to be taken when the vessel is calcified, which can be a potential cause of a weak seal.

Patient perception of ideal body weight and the effect of body mass index.

OBJECTIVE: Despite much effort, obesity remains a significant public health problem. One of the main contributing factors is patients' perception of their target ideal body weight. This study aimed to assess this perception. METHODS: The study took place in an urban area, with the majority of participants in the study being Hispanic (65.7%) or African-American (28.0%). Patients presented to an outpatient clinic were surveyed regarding their ideal body weight and their ideal BMI calculated. Subsequently they were classified into different categories based on their actual measured BMI. Their responses for ideal BMI were compared. RESULTS: In 254 surveys, mean measured BMI was 31.71 ± 8.01. Responses to ideal BMI had a range of 18.89-38.15 with a mean of 25.96 ± 3.25. Mean (±SD) ideal BMI for patients with a measured BMI of <18.5, 18.5-24.9, 25-29.9, and ≥30 was 20.14 ± 1.46, 23.11 ± 1.68, 25.69 ± 2.19, and 27.22 ± 3.31, respectively. These differences were highly significant (P < 0.001, ANOVA). CONCLUSIONS: Most patients had an inflated sense of their target ideal body weight. Patients with higher measured BMI had higher target numbers for their ideal BMI. Better education of patients is critical for obesity prevention programs.

Acute mesenteric, portal and inferior vena cava (IVC) venous thrombosis: optimal outcome achieved with anticoagulation.

The prevalence and clinical spectrum of acute mesenteric venous thrombosis (AMVT) in Pakistan is largely unknown. The authors report two patients with acute mesenteric, portal and inferior vena cava venous thrombosis confirmed on CT imaging. The diagnoses were established within 24 hours of presentation and both patients were successfully treated with therapeutic heparin during hospital admission and continued on oral warfarin because of hypercoagulable state. The protocol that we currently use is evidence based and is leading to optimal outcome.

Hepatic vein and inferior vena caval thrombus extending into the right atrium: a rare complication of amoebic liver abscess.

Amoebic liver abscess is an endemic in developing countries but few cases of associated vascular complications have been reported. The authors report a very rare vascular complication of hepatic veins and inferior vena caval (IVC) thrombosis extending into the right atrium in a young male with large amoebic liver abscess. Optimal result was achieved with early diagnosis on CT scan, percutaneous drainage of abscess, intravenous metronidazole, peri-operative anticoagulation, sternotomy and thrombectomy.

Amoebic liver abscess: experience in a south Asian country.

Amoebic liver abscess (ALA) is endemic in south Asian countries. The current study was undertaken in order to evaluate the clinical spectrum, management and outcome of ALA at an urban tertiary care hospital in Pakistan. The chart notes of 232 ALA patients admitted from 1 January 2000 to 31 August 2007 were retrospectively reviewed. The most frequent clinical findings included: fever (96.5%); right upper abdomen pain (80.2%); liver tenderness (73.5%); tachycardia (61.6%); hepatomegaly (60%); nausea and vomiting (42%); and jaundice (23.9%). The duration of symptoms was less than 14 days in 70% . Ultrasound examinations revealed 69% of the abscesses were in the right lobe, 19% in the left lobe and 12% in both lobes. The size of the abscess was greater than 5.0 cm in 83%. Seventy-seven percent of the patients had a single abscess and 23% had multiple abscesses. Ultrasound-guided therapeutic aspiration was performed in 64%, but 36% were treated with antibiotics alone. Metronodazole was the most frequently used antibiotic. However, various combinations of antibiotics were also used without any obvious justification.

Ileosigmoid knotting- a rare variant of bowel volvulus.

Two patients with acute intestinal obstruction underwent exploratory laparotomy after adequate fluid resuscitation and radiological imaging. A preoperative diagnosis of sigmoid volvulus and an operative diagnosis of ileosigmoid knotting or compound volvulus were established.

Acute mesenteric venous thrombosis: improved outcome with early diagnosis and prompt anticoagulation therapy.

AIM: To analyze the clinical spectrum of acute mesenteric venous thrombosis (AMVT), to assess the factors affecting the outcome and to determine the optimal management of this disease. METHODS: We retrospectively reviewed the case records of 20 patients with acute mesenteric venous thrombosis confirmed on CT imaging or on laparotomy over a 23 year period. Patients were divided into two groups according to the duration of symptoms: group I with symptoms for up to 3 days duration and group II with symptoms for more than 3 days. RESULTS: The mean age was 50.55 year, with 15 male and five female patients. In all patients the diagnosis were confirmed on CT imaging preoperatively except two patients when the diagnosis was established on exploratory laparotomy in the period before 1998. There were six patients in group I and 14 in group II. Five patients underwent an operation and one received a non-operative treatment in group I. Three patients underwent laparotomy and 11 received non-operative treatment in group II (P-value 0.01, Fisher's exact test). There were three and one mortality in groups I (n=6) and II (n=14) respectively (P-value 0.061, Fisher's exact test). Most patients received preoperative therapeutic anticoagulation. Two patients in group II who underwent exploratory laparotomy, neither did receive preoperative anticoagulation. Both patients died in the postoperative period. Eighteen patients were investigated for thrombophilia. Eleven patients had one (n=6) or more (n=5) identifiable hypercoagulable state, these included protein S deficiency (n=1), both protein C and S deficiency (n=5), polycythemia (n=2), factor V Leiden deficiency (n=1) and malignancy (n=2). None had antithrombin III deficiency, hyperhomocystine urea and contraceptive pill intake. There were no statistical differences between thrombophilic and non-thrombophilic patients regarding duration of symptoms, indications for laparotomy and 30 days mortality rate. CONCLUSIONS: Patients with AMVT of rapid onset (<3 days duration) had poor outcome and more patients required laparotomy because of extensive thrombosis leading to bowel gangrene and peritonitis. Early diagnosis with CT scanning, prompt treatment with anticoagulation in all patients, surgical treatment in cases of peritonitis or failure of medical treatment can contain the mortality rate in these patients.

Non-traumatic right hepatic artery pseudoaneurysm: an unusual cause of hemobilia and obstructive jaundice.

Most hepatic artery pseudoaneurysms (HAPA) are post traumatic, and non-traumatic pseudoaneurysm is rarely reported. It is a potentially life threatening vascular disorder and difficult to diagnose before rupture. Early diagnosis and prompt nonoperative intervention of this lesion could be life saving. The authors report the case of a patient with hemobilia caused by ruptured right hepatic artery pseudoaneurysm and subsequently developed right hepatic duct stricture, which has not been reported previously. This patient was successfully treated with endovascular stent graft of pseudoaneurysm and endoscopic stenting of right hepatic duct stricture.