Increased 18F-FDG uptake of hepatocellular carcinoma on positron emission tomography independently predicts tumor recurrence in liver transplant patients

The aim of this retrospective trial was to analyze the value of preoperative (18)F-fluoro-deoxyglucose positron emission tomography ((18)F-FDG PET) to predict parameters of tumor aggressiveness among liver transplant (OLT) patients with hepatocellular carcinoma (HCC). Fifty-five patients with HCC underwent (18)F-FDG-PET during evaluation for OLT. Nineteen patients demonstrated increased (18)F-FDG uptake on PET pre-OLT (PET(+)), and 36 patients revealed negative PET findings (PET(-)). PET(+) patients showed a relative risk of 9.5 and 6.4 for poor differentiation and for microvascular invasion (MVI) in the HCC at explant pathology, respectively. Of the 10 patients (18.2%) who developed HCC recurrences, 9 (90%) revealed increased (18)F-FDG uptake pre-OLT; only 1 (10%) showed a PET(-) status (P < .001). Apart from poor tumor differentiation, PET(+) status was identified as an independent predictor of tumor recurrence post-OLT (odds ratio, 23.9). Our study demonstrated that (18)F-FDG uptake on PET is a reliable preoperative predictor of tumor recurrence after OLT in patients with HCC, triggered by its high association with poor tumor differentiation and MVI.

18F-FDG-uptake of hepatocellular carcinoma on PET predicts microvascular tumor invasion in liver transplant patients

Vascular invasion of hepatocellular carcinoma (HCC) is a major risk factor for poor outcome after liver transplantation (LT). The aim of this retrospective analysis was to assess the value of preoperative positron emission tomography (PET) using (18)F-fluorodeoxyglucose ((18)F-FDG) in liver transplant candidates with HCC for predicting microvascular tumor invasion (MVI) and posttransplant tumor recurrence. Forty-two patients underwent LT for HCC after PET evaluation. Sixteen patients had an increased (18)F-FDG tumor uptake on preoperative PET scans (PET +), while 26 recipients revealed negative PET findings (PET-) pre-LT. PET- recipients demonstrated a significantly better 3-year recurrence-free survival (93%) than PET + patients (35%, p < 0.001). HCC recurrence rate was 50% in the PET + group, and 3.8% in the PET-population (p < 0.001). PET + status was identified as independent predictor of MVI [hazard ratio: 13.4]. Patients with advanced PET negative tumors and patients with HCC meeting the Milan criteria had a comparable 3-year-recurrence-free survival (80% vs. 94%, p = 0.6). Increased (18)F-FDG uptake on PET is predictive for MVI and tumor recurrence after LT for HCC. Its application may identify eligible liver transplant candidates with tumors beyond the Milan criteria.

ECG-guided central venous catheter positioning: does it detect the pericardial reflection rather than the right atrium?

BACKGROUND AND OBJECTIVE

Although electrocardiography (ECG) guidance of central venous catheters (CVCs) is traditionally thought to detect the entrance into the right atrium (RA), there is little evidence in the literature to confirm this. We previously observed a high incidence of left-sided CVCs abutting the wall of the superior vena cava (SVC), even when the catheters were advanced past the point of increased P-wave amplitude. Our hypothesis was that this ECG amplitude signal is actually detecting the pericardial reflection rather than the RA. The goal of the study was to position catheter tips under ECG guidance outside the RA.

METHODS

One-hundred central venous triple-lumen catheters inserted either via the right or the left internal jugular veins, respectively, were analysed in cardiac surgical patients. The position of the catheter tip was ascertained by ECG. METHOD A: A Seldinger guide-wire in the distal lumen served as exploring electrode, the respective insertion depth was recorded. METHOD B: The middle lumen (port opening 2.5 cm from the catheter tip, thus the catheter was advanced more towards the atrium) filled with a saline 10% fluid column served as the exploring electrode, and the insertion depth was recorded again. Descriptive data are given as mean+/-standard deviation.

RESULTS

On average, the catheters were advanced by the expected 2+/-0.3 cm using Method B beyond the initial insertion by Method A. All 100 CVCs were finally correctly positioned in the SVC and confirmed by transoesophageal echocardiography. When chest radiography was performed after surgery not a single catheter abutted the lateral wall of the SVC.

CONCLUSION

Since both methods detected the same structure, and catheters placed by Method B did not result in intra-atrial CVC tip position, the first increase in P-wave amplitude does correspond to a structure in the SVC, most likely the pericardial reflection.

Intra-atrial ECG is not a reliable method for positioning left internal jugular vein catheters

BACKGROUND

ECG guidance is widely used for positioning central venous catheters (CVCs) in the superior vena cava. We noticed a higher incidence of a more perpendicular angle between the catheter tip and the vessel wall after left-sided ECG-guided catheter positioning. To investigate the value of left-sided ECG guidance, we performed this prospective study.

METHODS

Of 114 patients, 53 were randomized to right and 61 to left internal jugular vein catheterization using a triple lumen catheter. Three methods to ascertain catheter tip position were sequentially applied in each patient, and the insertion depths (ID) obtained using each of the three methods were recorded: (i). ECG guidance with a Seldinger guide wire (ID-A); (ii). ECG guidance with saline 10% used as an exploring electrode (ID-B); (iii). from position ID-B, the catheter was rotated and advanced until all three lumina could be aspirated easily. The catheter was fixed in that position (ID-C). To determine final catheter tip position, intraoperative transoesophageal echocardiography (TOE) and a postoperative chest X-ray (CXR) were performed.

RESULTS

The depth of insertion of a catheter using the three methods varied significantly in left-sided (P<0.001), but not in right-sided catheters. Forty-eight of 57 (84%) left-sided CVCs, correctly positioned according to ECG guidance, had to be advanced further to achieve free aspiration through all three lumina. By this stage, five of the catheter tips had been positioned in the upper right atrium as demonstrated by TOE. There were 13 malpositions (23%) after left-sided insertion. In nine catheter malpositions, undetected by ECG guidance, the angle between the catheter tip and the lateral wall of the superior vena cava exceeded 40 degrees on CXR.

CONCLUSIONS

Intra-atrial ECG does not detect the junction between the superior vena cava and right atrium. It is not a reliable method for confirming position of left-sided CVCs. Post-procedural CXRs are recommended for left-sided, but not right-sided CVCs.

[Pseudoaneurysm--a rare complication of internal jugular vein cannulation: two case reports in liver transplant patients]

Internal jugular vein catheterization is nowadays a routine procedure in clinical practice. Arterial puncture is the most common complication of internal jugular vein catheterization. Two cases of pseudoaneurysm formation as a complication of accidental arterial puncture in liver transplant patients with coagulopathy are presented. Punctures of the common carotid artery, thyrocervical trunk, respectively were the source for these lesions. Coagulopathy is seen as an essential factor in the formation of pseudoaneurysm. Especially in patients with coagulopathy the threshold for ultrasound guidance should be low. Under these circumstances using the external jugular vein seems to be more prudent as it eliminates the risk for arterial punctures. We illuminate the genesis, signs and symptoms, diagnosis, and therapy of pseudoaneurysm. Recommendations for risk reduction are given.

Technical developments in cardiac MRI: 2000 update

In recent years, the technological developments in MRI have made it possible to perform routine cardiovascular imaging with MR. The availability of a vectorcardiogram, real time interactive scanning, SENSE and optimized protocols (balanced FFE) have made it possible to evaluate wall motion, perfusion and viability at rest and under stress. All vessels can be visualized, including the coronary arteries. In the near future, MRI will be capable of distinguishing between calcified and lipid plaque, and will even allow interventional applications.

Neuronavigation in surgery of intracranial and spinal tumors

PURPOSE

To demonstrate the new possibilities and advantages of neuronavigation in the surgery of intracranial and spinal tumors, based on patient populations treated in our hospital.

MATERIALS AND METHODS

An infrared navigation system with integrated microscope guidance was used for frameless intracranial neuronavigation. The biopsies of intracranial tumors were carried out using a frame-based stereotactic technique. Intracranial navigation was, in part, combined with the use of an intraoperative CT scanner and a three-dimensional ultrasound system for data acquisition, correction of brain shifts, and intraoperative quality control. The navigation was also supported by presurgical brain mapping with magnetic source imaging. Navigation in spinal surgery was exclusively performed using an infrared navigation system in combination with an intraoperative CT scanner.

RESULTS

The stereotactic tumor biopsies (n = 57) were carried out with an accuracy of 91.4% as compared with the histological diagnosis. The work flow of stereotactic procedures could be increased by using the intraoperative CT scanner. Fifty-seven patients with intracranial tumors were treated with the aid of neuronavigation between July 1997 and December 1999. These patients showed an improvement from 80% to 86% on the Karnofsky index 8 weeks postoperatively. The majority of intracranial cases were primary brain tumors (n = 30) and metastases (n = 13) in functionally important areas of the brain. In four patients, a significant brain shift was observed during neuronavigation, and could be corrected by an image update using either the intraoperative CT scanner (n = 2) or the three-dimensional ultrasound system (n = 2). The presurgical brain mapping with magnetoencephalography was shown to be reliable in the sensory cortex (n = 25). Eleven patients with a thoracic or lumbar tumor were treated by open surgery or stabilization, using a combination of spinal neuronavigation and the intraoperative CT scanner. Two patients with spinal tumors underwent navigated biopsies. Neither of them showed a reduction in the clinical stage, but the Karnofsky index improved from 63% up to 72% 8 weeks postoperatively.

CONCLUSION

Neuronavigation allows very precise intracranial and spinal surgery. The problem of brain shift during the navigation procedures has been solved by intraoperative image acquisition. The use of neuronavigation was shown to improve the postoperative quality of life of patients suffering from brain and spinal tumors.

Source localization and possible causes of interictal epileptic activity in tumor-associated epilepsy

Electrophysiological studies in gliomas have demonstrated action potentials in neoplastic cells. These "spiking tumor cells" are, however, an enigma. In attempt to find evidences for spikes within tumoral borders, 21 patients with different intracerebral tumors were preoperatively screened for the occurrence of epileptogenic discharges using multichannel MEG and EEG. A correlation between histopathology and the distance between dipole and tumor border could be found. Glioma patients showed epileptic activities closer to the border than those with mixed glioneuronal neoplasms and metastases. Four glioma patients demonstrated epileptic activity within the tumor boundary, however, not in the deep center of the tumor. Patch-clamping of cells from acute glioma slices did not yield a correlation between the presence of voltage-gated sodium channels in tumor cells and the MEG/EEG data. Our results demonstrate that the zone with the highest epileptogenic potential is different in gliomas and other brain tumors. However, our data do not strongly suggest that glioma cells are directly involved in the generation of tumor-associated epilepsy in vivo via their capability to generate action potentials.