Peter Smeets

Effects of Hemi-Portocaval Shunts For Inflow Modulation on the Outcome of Small-for-Size Grafts in Living Donor Liver Transplantation

Graft hyperperfusion in small‐for‐size grafts (SFSG) is considered the main causal factor of small‐for‐size syndrome (SFSS). We compared SFSG with a graft‐to‐recipient body ratio ≤0.8, with and without graft inflow modulation (GIM) by means of a hemi‐portocaval shunt (HPCS). Thirteen patients underwent adult‐to‐adult living donor liver transplantation (AALDLT): G1, n = 5 [4 right livers (RL) and 1 left liver (LL)] without GIM, and G2, n = 8 (4 RL and 4 LL) with GIM. In G2 patients, portal vein flow (PVF) was significantly reduced by HPCS: 190 ± 70 mL/min/100 g liver in G2 vs. 401 ± 225 ml/min in G1 (p = 0.002). One‐ and 6‐month post‐transplantation graft volume/standard liver volume (GV/SLV) ratio was of 72% and 79.5% in G1; 80% and 101% in G2 (p = ns). SFSS was observed in three G1 recipients (who were retransplanted), but in none of the G2 patients. At 1‐year, patient and graft survival was respectively of 40% and 20% in G1, 87.5% and 75% in G2 (p = 0.024 and 0.03).

Modulation of Portal Graft Inflow: A Necessity in Adult Living-donor Liver Transplantation?

ObjectiveTo evaluate the clinical significance of modulating the recipient portal inflow (rPVF) through perioperative ligation of the splenic artery in adult living-donor liver transplantation (ALDLTx) by focusing on vascular complications, intractable ascites production, and the prevention of small-for-size syndrome (SFSS). Summary Background DataIn ALDLTx, portal graft flow is enhanced to at least twice the donor value, raising the total liver inflow. Recipient hepatic arterial flow (rHAF) is lower than expected. Portal hyperperfusion of small grafts in larger recipients is thought to be one of the main causes of posttransplant graft dysfunction/SFSS. MethodsSeventeen ALDLTx were reviewed for a minimum of 2 months. Patients were divided retrospectively into two groups: G1 (n = 7), without modulation of rPVF, and G2 (n = 10), with splenic artery ligation to decrease rPVF perioperatively. Donor and recipient hepatic hemodynamics were evaluated against graft function and outcome, including correlations between rPVF, graft weight, graft:recipient body weight ratio, and recipient weight. ResultsFollowing portal and arterial reperfusion, mean rPVF and rPVF/graft weight were much higher than in the donors, whereas mean rHAF and rHAF/graft weight were much lower. No differences were found between groups, except for rPVF and rHAF, which were much more higher and lower, respectively, before splenic artery ligation. In G1 patients, SFSS was seen in two patients and vascular complications occurred in two others. In G2 patients, splenic artery ligation permitted a significant decrease in rPVF, an improvement in rHAF, and the resolution of refractory ascites. Neither SFSS nor vascular complications were seen in G2 patients. ConclusionsWhen a suboptimal graft:recipient body weight ratio is accompanied by high rPVF in ALDLTx, the portal flow should be modulated perioperatively; splenic artery ligation is a simple and safe method that is sufficient to allow this modulation in most patients.

Predictive and prognostic value of metabolic tumour volume and total lesion glycolysis in solid tumours

Data available in patients suffering from squamous cell carcinoma of the head and neck, lung carcinoma, oesophageal carcinoma and gynaecological malignancies suggest that metabolic tumour volume and to a lesser extent total lesion glycolysis have the potential to become valuable in the imaging of human solid tumours as prognostic biomarkers for short- to intermediate-term survival outcomes, adding value to clinical staging, for assessment of response to treatment with neoadjuvant and concurrent chemotherapy, and for treatment optimization; for example, based on early treatment response assessment using changes in metabolic tumour volume over time, it might be possible to select patients who require a more aggressive treatment to improve their outcome. Prospective studies enrolling consecutive patients, adopting standardized protocols for FDG PET acquisition and processing, adjusting for potential confounders in the analysis (tumour size and origin) and determining the optimal methodology for determination of these novel markers are mandatory.

The value of laparoscopic liver surgery for solid benign hepatic tumors

BackgroundLaparoscopic liver resection (LLR) has gained wide acceptance for various liver resection procedures, mainly for benign diseases. However, only small series have been reported from a few selected centers.MethodsBetween January 2001 and January 2006, a total of 629 liver resections were performed at our institution. The indication was solid benign liver tumor in 56 (8.9%) patients. LLR was performed in 20 (35.7%) cases. Data from the LLR group were compared with those from a consecutive control group undergoing open liver surgery (OS) for similar indications in a matched-pair analysis during the same period. The pairs were matched as closely as possible for age, gender, American Society of Anesthesiologists (ASA) score, indication for resection, and type and location of the lesions. The endpoint was to investigate overall morbidity and outcome.ResultsAll patients but one are alive and well after a mean follow-up of 35 months (range 10–60 months). Conversion laparotomy was required in two out of 20 (10%) cases for uncontrolled bleeding (one requiring temporary hemodialysis). LLR was characterized by faster time to first oral intake and shorter hospital stay compared to OS (p = 0.001 and 0.008, respectively). Incisional hernias (25%) were only recorded in the OS (p = 0.047 vs. LLR). Overall morbidity was 45% in OS versus 20% in LLR (p = 0.3).ConclusionsLLR significantly reduced time to oral intake, hospital stay, and incisional hernias compared to OS. Bleeding is a major risk and should be carefully considered when resecting benign tumors. In the hands of expert surgeons, LLR may become the gold standard for the resection of benign liver tumors located in the anterior and lateral sectors and for minor hepatic resections.

Pure laparoscopic full-left living donor hepatectomy for calculated small-for-size LDLT in adults: proof of concept.

Adult‐to‐adult living donor liver transplantation (A2ALDLT) is an accepted mode of treatment for end‐stage liver disease. Right‐lobe grafts have usually been preferred in view of the higher graft volume, which lowers the risk of a small‐for‐size syndrome. However, donor left hepatectomy is associated with less morbidity than when it is compared to right hepatectomy. Laparoscopic donor hepatectomy (LDH) has been considered almost exclusively in pediatric transplantation. The results of laparoscopic left‐liver graft procurement for calculated small‐for‐size A2ALDLT in four donors are presented. The graft‐to‐recipient body weight ratio was <0.8 in all recipients. The mean portal vein flow and the pressure and hepatic artery flows were measured at 190 ± 56 mL/min/100 g, 13 ± 1.4 mm/Hg and 109 ± 19 mL/min, respectively. No early postoperative donor complications were recorded. One graft was lost due to intrahepatic abscesses. Asymptomatic stenosis of a right posterior duct was treated with a Roux‐en‐Y loop 4 months later in one donor. We show that LDH of the full‐left lobe is feasible. LDH is a very demanding operation, potentially decreasing donor morbidity. Standardization of this procedure, making it accessible to the growing number of experienced laparoscopic liver surgeons, could help renewing the interest for A2ALDLT in the Western world.

Laparoscopic liver resection compared to open approach in patients with colorectal liver metastases improves further resectability: Oncological outcomes of a case-control matched-pairs analysis

AIMS Liver resection is considered the standard treatment of colorectal metastases (CRLM). However, to date, no long term oncological results and data regarding repeat hepatectomy after laparoscopic approach are known. The aim of this study is to analyze single center long-term surgical and oncological outcomes after liver resection for CRLM. METHODS A total of 57 open resections (OR) were matched with 57 laparoscopic resections (LR) for CRLM. Matching was based mainly on number of metastases, tumor size, segmental position of lesions, type of hepatectomy and type of resection. RESULTS Morbidity rate was significantly less in the LR group (p = 0.002); the length of hospital stay was 6.5 ± 5 days for the LR group and 9.2 ± 4 days for the OR group (p = 0.005). After a median follow up of 53.7 months for the OR group and 40.9 months for the LR group, the 5-y overall survival rate was 65% and 60% respectively (p = 0.36) and the 5-y disease free survival rate was 38% and 29% respectively (p = 0.24). More patients in the LR group received a third hepatectomy for CRLM relapse than in the OR group (80% vs. 14.3% respectively; p = 0.015). CONCLUSIONS Laparoscopic resection for CRLM offers advantages in terms of reduced blood loss, morbidity rate and hospital stay. It provides comparable long-term oncological outcomes but can improve further resectability in patients with recurrent disease.

Correlation of Contrast-Detail Analysis and Clinical Image Quality Assessment in Chest Radiography with a Human Cadaver Study

PURPOSE To determine the correlation between the clinical and physical image quality of chest images by using cadavers embalmed with the Thiel technique and a contrast-detail phantom. MATERIALS AND METHODS The use of human cadavers fulfilled the requirements of the institutional ethics committee. Clinical image quality was assessed by using three human cadavers embalmed with the Thiel technique, which results in excellent preservation of the flexibility and plasticity of organs and tissues. As a result, lungs can be inflated during image acquisition to simulate the pulmonary anatomy seen on a chest radiograph. Both contrast-detail phantom images and chest images of the Thiel-embalmed bodies were acquired with an amorphous silicon flat-panel detector. Tube voltage (70, 81, 90, 100, 113, 125 kVp), copper filtration (0.1, 0.2, 0.3 mm Cu), and exposure settings (200, 280, 400, 560, 800 speed class) were altered to simulate different quality levels. Four experienced radiologists assessed the image quality by using a visual grading analysis (VGA) technique based on European Quality Criteria for Chest Radiology. The phantom images were scored manually and automatically with use of dedicated software, both resulting in an inverse image quality figure (IQF). Spearman rank correlations between inverse IQFs and VGA scores were calculated. RESULTS A statistically significant correlation (r = 0.80, P < .01) was observed between the VGA scores and the manually obtained inverse IQFs. Comparison of the VGA scores and the automated evaluated phantom images showed an even better correlation (r = 0.92, P < .001). CONCLUSION The results support the value of contrast-detail phantom analysis for evaluating clinical image quality in chest radiography.

Dose-length product of scanners correlates with DNA damage in patients undergoing contrast CT

OBJECTIVES Computed tomography (CT) exams contribute for a large part to the populations radiation burden. This study addresses the question if dose settings of scanners expressed by dose-length product (DLP) are correlated with directly measurable biological effects in patients. METHODS DLP, blood dose, effective dose and DNA damage were analyzed for patients undergoing a thoracic or abdominal contrast CT scan on two CT scanners with different dose settings. The DNA damage was assessed by scoring γ-H2AX foci representing DNA double-strand breaks (DSBs) in patients lymphocytes. Blood dose was calculated using the ImPACT software. RESULTS The CT system operating at higher dose settings represented by higher DLP values, resulted in a significantly higher number of radiation-induced γ-H2AX foci in patients lymphocytes (DLP: 2.1 times higher; γ-H2AX foci: 2.3 times higher; p<0.05). Plotting γ-H2AX foci versus blood dose showed a systematic increase of DNA damage with dose. In vitro experiments ruled out a possible X-ray enhancement of DNA damage effect by contrast agent. CONCLUSIONS Present study demonstrates that optimization of DLP setting of scanners results in a reduction of X-ray effects in patients.

Image Quality and Radiation Dose on Digital Chest Imaging: Comparison of Amorphous Silicon and Amorphous Selenium Flat-Panel Systems

OBJECTIVE The aim of this study was to compare the image quality and radiation dose in chest imaging using an amorphous silicon flat-panel detector system and an amorphous selenium flat-panel detector system. In addition, the low-contrast performance of both systems with standard and low radiation doses was compared. MATERIALS AND METHODS In two groups of 100 patients each, digital chest radiographs were acquired with either an amorphous silicon or an amorphous selenium flat-panel system. The effective dose of the examination was measured using thermoluminescent dosimeters placed in an anthropomorphic Rando phantom. The image quality of the digital chest radiographs was assessed by five experienced radiologists using the European Guidelines on Quality Criteria for Diagnostic Radiographic Images. In addition, a contrast-detail phantom study was set up to assess the low-contrast performance of both systems at different radiation dose levels. Differences between the two groups were tested for significance using the two-tailed Mann-Whitney test. RESULTS The amorphous silicon flat-panel system allowed an important and significant reduction in effective dose in comparison with the amorphous selenium flat-panel system (p < 0.0001) for both the posteroanterior and lateral views. In addition, clinical image quality analysis showed that the dose reduction was not detrimental to image quality. Compared with the amorphous selenium flat-panel detector system, the amorphous silicon flat-panel detector system performed significantly better in the low-contrast phantom study, with phantom entrance dose values of up to 135 muGy. CONCLUSION Chest radiographs can be acquired with a significantly lower patient radiation dose using an amorphous silicon flat-panel system than using an amorphous selenium flat-panel system, thereby producing images that are equal or even superior in quality to those of the amorphous selenium flat-panel detector system.

F-18 Fluorodeoxyglucose Pet/ct Scanning in the Diagnostic Work-up of a Primary Pericardial Mesothelioma: A Case Report

Primary mesothelioma of the pericardium is a very rare malignancy. The antemortem diagnosis is difficult and requires a multidisciplinary approach. The use of F-18 fluorodeoxyglucose-positron emission tomography/computed tomography whole body scan has been recently advocated to improve staging and to monitor treatment in pleural mesothelioma. This is the first case describing the use of F-18 fluorodeoxyglucose-positron emission tomography/computed tomography in the diagnostic work-up of a primary pericardial mesothelioma.