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Biomedical subjects

B Jawan

Publications and source records attributed to B Jawan.

At least 55 records · Page 3Linked to original sources
PubMed1999

Magnetic resonance of the hepatic veins with angular reconstruction: application in living-related liver transplantation.

BACKGROUND: Preoperative mapping of the hepatic venous system of the partial liver graft is indispensable to the success of living-related liver transplantation. We assessed the accuracy of magnetic resonance (MR) venography with angular reconstruction in depicting the tributaries of the middle hepatic vein and left hepatic vein in the donors, which was essential in graft retrieval and venoplasty. METHODS: Nineteen living-related liver transplantation donors underwent a pretransplantation survey, including sonography and MRI for hepatic venous evaluation. T1-weighted images were reconstructed manually, using the inferior vena cava as a fixed point for tilting to produce an oblique plane image where both the middle hepatic vein and left hepatic vein could be demonstrated draining into the inferior vena cava. The reconstructed images of the hepatic veins were compared with preoperative sonography, intraoperative sonography, and operative findings. RESULTS: Preoperative sonography and MR findings correlated well with the operative findings in the major hepatic veins. The MR venography of the ramification of the hepatic veins has an accuracy of 93%, the sonography, 84%. Sonography is slightly inferior in the evaluation of the hepatic vein in segment 4 and the left superior hepatic vein, with an accuracy of 73% and 67%, respectively. CONCLUSION: MR venography with angular reconstruction is accurate in depicting the complex distribution of the hepatic veins of the left liver, providing important information for decision making as to the cutting plane during graft retrieval and the method of venoplasty and anastomosis. Thus, unnecessary blood loss could be avoided and vascular complications could be prevented, as these conditions would be unacceptable for a healthy living donor. We propose that MR venography, a rapid and reliable technique, is an appropriate alternative examination or complementary modality to sonography in the pretransplantation evaluation of the living donor.

Adult↗
PubMed1999

Aspiration and transtracheal jet ventilation with different pressures and depths of chest compression.

OBJECTIVE: To evaluate aspiration prophylaxis during cardiopulmonary resuscitation (CPR) using transtracheal jet ventilation (TJV) with different pressure-depths of chest compression and chest compression alone without mechanical ventilation. DESIGN: Prospective, animal study. SETTING: Animal research laboratory, Chang Gung Memorial Hospital, Kaohsiung Medical Center, Taiwan. SUBJECTS: Mongrel dogs (n = 10) weighing 8 to 12 kg. INTERVENTIONS: Eight mongrel dogs were anesthetized, paralyzed, and ventilated transtracheally with a jet ventilator at frequencies varied from 600 to 10 cycles/min. The airway pressures below and above the jetting port were measured. The mouth of the dog was filled with barium and chest radiographs were taken 10 mins after chest compression with 20-pound pressure and 5-cm depth in group 1 and 10-pound pressure and 3-cm depth in group 2 at each different jet frequency. Two additional dogs underwent the same procedures but received only chest compression without TJV. MEASUREMENTS AND MAIN RESULTS: Pulmonary aspiration was not noted in the chest radiographs from either group. The airway pressure changes between groups were not significantly affected by difference in pressures and depths of chest compression at the same jetting frequency. However, pulmonary aspiration occurred in the two dogs that received chest compression alone without TJV. CONCLUSIONS: Application of TJV during chest compression with different pressures and depths caused no pulmonary aspiration in dogs at frequencies between 600 and 10 cycles/min. The protection against aspiration disappeared if the dogs received only chest compression without TJV. The mechanism of preventing pulmonary aspiration in TJV is thought to be due to forceful unidirectional gas outflow through the larynx and higher airway pressure in the carina than in the upper airway. The airway pressures were not affected by different chest compression pressures and depths because the larynx stayed open during TJV and the air outflow could freely move out without increasing the pressure in the airway.

Animals↗
PubMed1999

Intubation of newborn during delivery with intact umbilical cord--a case report.

A 24-year-old gravida 2, para 1 woman at 38th week gestation was scheduled for elective Cesarean section (C/S) because of a previous C/S and prenatal diagnosis of congenital diaphragmatic hernia. We decided to intubate the newborn during delivery before the umbilical cord was cut. After delivery of the fetal head and part of the shoulders, the mouth of the fetus was cleared and the trachea was intubated orally with a 2.5 mm internal diameter (I.D.) endotracheal tube under sterile conditions while the uteroplacental circulation was still intact. The patient had to be repeatedly resuscitated due to bradycardia in intensive care unit. No surgical correction of the hernia was attempted because of the poor condition of the baby, which died 3.5 hours after birth. Although our case ended up in mortality despite successful perinatal intubation, we recommend that in case where airway or ventilatory problems are anticipated, tracheal intubation is done during delivery before the umbilical cord is clamped. When the fetus is sharing the maternal circulation, it will allow physicians to have more time and safety to perform corrective measures.

Adult↗
PubMed1998

A transient increase in endogeneous erythropoietin levels after paediatric liver transplantation.

We investigated whether liver transplantation affects endogeneous erythropoietin (EPO) synthesis. Serum EPO levels were measured before transplantation and during the peri-transplant period in ten consecutive paediatric patients who had received a liver allograft without recombinant EPO therapy. All patients were anaemic on post-operative day 1 (POD 1); however, the haemoglobin levels of three patients gradually increased and required phlebotomy on POD 5-9. The serum levels of EPO in all patients were within the normal range before surgery, but six of the ten patients had a transient increased level of EPO at 1248 h after transplantation. A transient increase of endogeneous EPO following paediatric liver transplantation may be associated with extramedullary erythropoiesis in human liver grafts.

Child↗
PubMed1998

Intraoperative Doppler ultrasound in liver transplantation.

The purpose of this study was to determine the utility of intraoperative Doppler ultrasound for the diagnosis and reduction of the vascular complications in liver transplantation. This study included 19 pediatric and 5 adult patients. In the pediatric group, 12 patients received living related liver transplantation (LRLT), two splitting liver transplantation (SLT), three reduced-size liver transplantation (RLT) and two full-size pediatric liver transplants (FPLT). The hemodynamics and waveform of the hepatic vein, portal vein and hepatic artery were evaluated by intraoperative Doppler ultrasound (US) after reperfusion of the graft. Unsatisfactory hemodynamics was identified in nine cases, including decrease hepatic venous flow (6-9 cm/s) with non-pulsative flat waveform (adults, n = 2 and LRLT, n = 2); portal vein thrombosis (LRLT, n = 1); decrease portal flow (8 mL/min/kg) (LRLT, n = 1); occlusion of the portal vein (SLT, n = 1); poor arterial flow with dampened artery waveform (FPLT, n = 2). These abnormalities were all successfully re-reconstructed by surgical procedures and achieved a graft survival rate of 100%. Two late vascular complications including hepatic venous thrombosis and recurrent portal vein stenosis with splenorenal shunt were discovered 1 month later. They were treated effectively by surgical thrombolectomy and percutaneous balloon dilatation and metallic coils embolization respectively. Three patients died of non-vascular complications and all patients who underwent LRLT survived with a resultant 87.5% overall survival rate. In conclusion, intraoperative Doppler US is efficient in detecting abnormal hepatic hemodynamics, which permits early intervention and hence a better prognosis for the patients. Re-reconstructive procedures were monitored closely under Doppler US guidance until proper flow and wave-form were established. This reduces post-transplant vascular complications and thereby eliminates the likelihood of a lethal complication that might call for re-transplantation.

Adolescent↗
PubMed1998

Post-transplant changes of segment 4 after living related liver transplantation.

The purpose of this study was to evaluate the outcome of the medial segment of the graft after living related liver transplantation (LRLT). Of the 12 pediatric recipients who underwent LRLT, 2 received whole left liver graft, 1 left lateral segment graft, and 9 extended left lateral segment grafts. The hepatic veins of the donor were reviewed and the volume of the medial segment and left lateral liver was measured before and 6 months after liver transplantation. The flow velocity and direction of the portal vein in the medial segment graft was also evaluated by Doppler ultrasound. The grafted livers of all recipients showed a substantial increase in volume of 9-120% 6 months after LRLT. For the left lateral segment, an increase in volume was found in all cases ranging from 21 to 245%. For the medial segment, volume increases of 5-48% were found in seven cases with normal hepatopetal flow detected inside the segment 4 intrahepatic portal vein. In four cases, the partial medial segment graft of the extended left lateral liver graft decreased in volume from 33 to 69%. Among these four cases, slow flow (n = 2) and hepatofugal flow (n = 1) were also detected in the intrahepatic portal vein of the medial segment. Mapping of the tributary of the hepatic veins of the graft revealed inadequate venous drainage of the partial segment 4 graft, which may be considered as the cause of the atrophic change of the partial segment 4 graft. In conclusion, different regenerative rates between the left lateral segment and the medial segment were noted, with a greater rate in the left lateral segment. The venous drainage of the medial segment is of primary concern in the determination of the outcome of the regeneration. Atrophic change occurs when inadequate hepatic venous drainage is encountered. Therefore, if an extended left lateral liver graft is required, the corresponding draining veins of the partial medial segment must be preserved. Otherwise, whole left liver or left lateral segment graft would be a better choice.

Blood Flow Velocity↗