Johan S Laméris

Academisch Medisch Centrum Universiteit van Amsterdam | AMC · Department of Radiology

Background & Aims: In a 2010 randomized trial (the PANTER trial), a surgical step-up approach for infected necrotizing pancreatitis was found to reduce the composite endpoint of death or major complications compared with open necrosectomy; 35% of patients were successfully treated with simple catheter drainage only. There is concern, however, that...

Background: Infected necrotising pancreatitis is a potentially lethal disease and an indication for invasive intervention. The surgical step-up approach is the standard treatment. A promising alternative is the endoscopic step-up approach. We compared both approaches to see whether the endoscopic step-up approach was superior to the surgical step-...

Background: The optimal diagnostic strategy and timing of intervention in infected necrotizing pancreatitis is subject to debate. We performed a survey on these topics amongst a group of international expert pancreatologists. Methods: An online survey including case vignettes was sent to 118 international pancreatologists. We evaluated the use a...

The purpose of this article is to review imaging workup of perihilar cholangiocarcinoma, including MDCT and MRI protocols, imaging findings, differential diagnosis, and staging. A reporting template is included. Imaging plays a central role in the detection, differential diagnosis, and staging of perihilar cholangiocarcinoma.

Choledocholithiasis is a common complication of cholecystolithiasis, occurring in 15-20% of patients who have gallbladder stones. Endoscopic retrograde cholangio-pancreatography is the standard treatment. When this is not possible or not feasible, percutaneous transhepatic stone removal is an alternative treatment. In this retrospective study, we a...

Background & AimsHepatocellular secretory failure induced by drugs, toxins or transient biliary obstruction may sometimes persist for months after removal of the initiating factor and may then be fatal without liver transplantation. We characterized patients with severe persistent hepatocellular secretory failure (PHSF) and treated them with the pr...

This study was designed to determine the effectiveness of percutaneous balloon dilation and long-term drainage of postoperative benign biliary strictures. Medical records of patients with postoperative benign biliary strictures, in whom percutaneous transhepatic biliary drainage (PTBD) and balloon dilation was performed between January 1999 and Dec...

Infected necrotising pancreatitis is a potentially lethal disease that nearly always requires intervention. Traditionally, primary open necrosectomy has been the treatment of choice. In recent years, the surgical step-up approach, consisting of percutaneous catheter drainage followed, if necessary, by (minimally invasive) surgical necrosectomy has...

Obstructive jaundice, clinically evident by jaundiced skin, nausea, pruritus, dark urine and discoloration of stool, is the most prevalent presenting symptom of hilar cholangiocarcinoma (HCCA). Obstructive jaundice is associated with a proinflammatory state, resulting from portal and systemic endotoxemia, increased permeability of the intestinal mu...

The relationship between hospital volume and outcome of care after pancreatic surgery, particularly mortality, has been described extensively in the past. Today, this relationship is frequently being used by healthcare providers and/or insurance companies to select hospitals for various surgical procedures. This concept, however, has many limitatio...

Purpose This is a review of literature on the indications, technique, and outcome of portal vein embolization (PVE). Methods A systematic literature search on outcome of PVE from 1990 to 2011 was performed in Medline, Cochrane, and Embase databases. Results Forty-four articles were selected, including 1,791 patients with a mean age of 61 ± 4.1 ye...

Alternative methods to optimize the hypertrophy response after portal vein embolization (PVE) are desired. This study assessed the effect of hepatic vein embolization (HVE) in addition to PVE on liver hypertrophy response in a standardized rabbit model. Thirty rabbits were allocated to groups according to intervention: PVE alone, HVE alone, and a c...

This article represents the author's personal view and experience on the gradual shift from diagnostic to interventional radiology during the past 30 years. The first interventional procedures almost exclusively concerned vascular medicine. Progress in cross-sectional imaging with ultrasound, CT and MRI opened opportunities for further applications...

Effective diagnosis and treatment of patients with hilar cholangiocarcinoma (HCCA) is based on the synergy of endoscopists, interventional radiologists, radiotherapists and surgeons. This report summarizes the multidisciplinary experience in management of HCCA over a period of two decades at the Academic Medical Center in Amsterdam, with emphasis o...

Three male patients aged between 50 and 70 years were referred with jaundice and weight loss. Imaging showed a pancreatic mass and changes in the calibre of the choledochal or pancreatic duct, suggestive of malignancy. Two patients were operated on. One patient was considered to have an unresectable carcinoma but showed remarkable clinical improvem...

Low endothelial shear stress (ESS) elicits endothelial dysfunction. However, the relationship between ESS and arterial remodeling and arterial stiffness is unknown in humans. We developed a 3.0-T MRI protocol to evaluate the contribution of ESS to arterial remodeling and stiffness. Fifteen young (aged 26 ± 3 years) and 15 older (aged 57 ± 3 years)...

Necrotizing pancreatitis with infected necrotic tissue is associated with a high rate of complications and death. Standard treatment is open necrosectomy. The outcome may be improved by a minimally invasive step-up approach. In this multicenter study, we randomly assigned 88 patients with necrotizing pancreatitis and suspected or confirmed infected...

To determine the result of surgical treatment of patients with hilar cholangiocarcinoma (HCCA) before and after the transition from predominantly local bile duct resections to more extensive resections including partial liver resection in order to achieve complete tumour resection in the Academic Medical Center, Amsterdam (The Netherlands). Retrosp...

Background: Necrotizing pancreatitis with infected necrotic tissue is associated with a high rate of complications and death. Standard treatment is open necrosectomy. The outcome may be improved by a minimally invasive step-up approach. Methods: In this multicenter study, we randomly assigned 88 patients with necrotizing pancreatitis and suspected...

Controversy exists over the preferred technique of preoperative biliary drainage (PBD) in patients with hilar cholangiocarcinoma (HCCA) requiring major liver resection. The current study compared outcomes of endoscopic biliary drainage (EBD) and percutaneous transhepatic biliary drainage (PTBD) in patients with resectable HCCA. One hundred fifteen...

Portal vein embolization is an accepted method to increase the future remnant liver preoperatively. The aim of this study was to assess the effect of preoperative portal vein embolization on liver volume and function 3 months after major liver resection. This is a retrospective case-control study. Data were collected of patients who underwent porta...

Is transjugular intrahepatic portosystemic shunt (TIPS) preferable to a surgical shunting procedure in patients who are expected to benefit from a portal-systemic shunt? Since randomized trials comparing these procedures have not yet been reported, we attempted to define the present best therapeutic strategy by reviewing both the recent literature...

We compared in vivo 3.0-T magnetic resonance (MR) images of the carotid artery wall in piglets to intima-media thickness measurements of similar carotid segments by B-mode ultrasound (US) and histology to define the corresponding anatomical tissue characteristics and accuracy of carotid MR images. Carotid MR is increasingly used for the assessment...

The aim of this study was to assess the role of postmortem computed tomography (PMCT) as an alternative for autopsy in determining the cause of death and the identification of specific injuries in trauma victims. A systematic review was performed by searching the EMBASE and MEDLINE databases. Articles were eligible if they reported both PMCT as wel...

Our aim was to compare common carotid mean wall thickness (MWT) measurements by 3.0-T MRI with B-mode ultrasound common carotid intima-media thickness (CCIMT) measurements, a validated surrogate marker for cardiovascular disease. B-mode ultrasound and 3.0-T MRI scans of the left and right common carotid arteries were repeated 3 times in 15 healthy...

The current terminology for describing peripancreatic collections in acute pancreatitis (AP) derived from the Atlanta Symposium (e.g. pseudocyst, pancreatic abscess) has shown a very poor interobserver agreement, creating the potential for patient mismanagement. A study was undertaken to determine the interobserver agreement for a new set of morpho...

Bile duct injury (BDI) is associated with increased morbidity and poor survival. The aim of the present study was to compare quality of life (QoL) between patients with BDI and those without after laparoscopic cholecystectomy. A longitudinal assessment was performed and risk factors for poor QoL were determined. In March 2005 a survey was performed...

Percutaneous biliary drainage and stenting (PTBD) for palliation of malignant obstructive jaundice has evolved to a safe and effective technique. PTBD is equally effective for treatment of distal and proximal bile obstruction. Metal self-expandable stents have proved superior to plastic stents and should therefore be used. Technical success is >90%...

Portal vein embolization (PVE) has reached worldwide acceptance to increase future remnant liver (FRL) volume before undertaking major liver resection. The aim of this overview is to point out and discuss current controversies in the application of PVE. Review of literature pertaining to techniques of PVE, complications, tumor proliferation, timing...

In recent decades, image-guided interventions have become daily routine in radiology departments worldwide. Radiologists and clinicians alike clearly see the advantages of image-guided interventions, as it is minimally invasive, well tolerated by patients and has shown to have a low level of complications.

To compare endoscopic and surgical drainage of the pancreatic duct for ductal decompression in patients with severe pain due to chronic pancreatitis and a dilated pancreatic duct. Randomized clinical trial. All symptomatic patients with chronic pancreatitis and a distal obstruction of the pancreatic duct, but without an inflammatory mass, were elig...

To evaluate the frequency of claims for damages initiated by patients referred to a tertiary centre for the treatment of bile-duct injury after a (laparoscopic) cholecystectomy. To determine the relationship between patient characteristics and the initiation of a claim procedure. Descriptive. Between 1 January 1990 and 31 December 2005, 500 patient...

As demand for health care increases, a high efficiency on limited resources is necessary for affordable high patient service levels. Here, we present an adaptive approach to efficient resource usage by automatic optimization of resource calendars. We describe a precise model based on a case study at the radiology department of the Academic Medical...

Bile duct injury (BDI) after laparoscopic cholecystectomy (LC) has an enormous socioeconomic impact on patients. BDI has been associated with severe morbidity, impaired survival, and poor long-term quality of life. This study was performed to analyze the impact of a multidisciplinary approach in BDI patients on survival. A prospective cohort study...

To evaluate the results of the treatment of simple liver cysts (solitary and multiple) and polycystic liver disease (PLD) using percutaneous sclerotherapy and/or surgical procedures in a single tertiary referral centre. Retrospective analysis of 54 patients referred for evaluation and possible treatment of simple liver cysts (solitary and multiple)...

The aim of our study was to compare primary three-dimensional (3D) and primary two-dimensional (2D) review methods for CT colonography with regard to polyp detection and perceptive errors. CT colonography studies of 77 patients were read twice by three reviewers, first with a primary 3D method and then with a primary 2D method. Mean numbers of true...

The management of a bile duct injury detected during laparoscopic cholecystectomy is still under discussion. An end-to-end anastomosis (with or without T-tube drainage) in peroperative detected bile duct injury has been reported to be associated with stricture formation of the anastomosis area and recurrent jaundice. Between 1991 and 2005, 56 of a...

For patients with chronic pancreatitis and a dilated pancreatic duct, ductal decompression is recommended. We conducted a randomized trial to compare endoscopic and surgical drainage of the pancreatic duct. All symptomatic patients with chronic pancreatitis and a distal obstruction of the pancreatic duct but without an inflammatory mass were eligib...

The 1992 Atlanta classification is a clinically based classification system that defines the severity and complications of acute pancreatitis. A study was undertaken to assess the interobserver agreement of categorizing peripancreatic collections on computed tomography (CT) using the Atlanta classification. Preoperative contrast-enhanced CTs from 7...

The purpose of this study was to estimate the effective dose that is currently used in CT colonography using scan parameters that were collected for this purpose, and to investigate trends in time. PubMed was systematically searched from 1996 until January 2004 for studies investigating CT colonography. Research institutions were contacted and aske...

Endoscopy is the primary diagnostic and therapeutic modality for the vast majority of patients with haemorrhage of the upper or lower digestive tract. In many hospitals, surgery is the therapy of choice when endoscopy fails or is impossible. In patients who have considerable co-morbidity and who are actively bleeding from the digestive tract, surge...

The initial treatment of acute necrotizing pancreatitis is conservative. Intervention is indicated in patients with (suspected) infected necrotizing pancreatitis. In the Netherlands, the standard intervention is necrosectomy by laparotomy followed by continuous postoperative lavage (CPL). In recent years several minimally invasive strategies have b...

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Abstract Background The initial treatment of acute necrotizing pancreatitis is conservative. Intervention is indicated in patients with (suspected) infected necrotizing pancreatitis. In the Netherlands, the standard intervention is necrosectomy by laparotomy followed by continuous postoperative lavage (CPL). In recent years several minimally inva...

This study analyzes the change in the management of biliary leakage after hepaticojejunostomy. Between 1993 and 2003 all patients (n = 1033) were studied with a hepaticojejunostomy as part of a pancreatoduodenectomy (n = 486), proximal bile duct resection (without liver resection) (n = 35), and biliodigestive bypass for malignant (n = 302) and beni...

To compare ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI) in the diagnosis and determination of resectability of pancreatic adenocarcinoma. Articles reporting US, CT, or MRI data of patients with known or suspected pancreatic adenocarcinoma and at least 20 patients verified with histopathology, surgical finding...

Survival is often poor after resection of pancreatic tumors. We correlated the pre-operative CTs with survival to find criteria that have prognostic value. To establish the prognostic value of CT in patients with potentially resectable pancreatic head carcinoma. In 71 consecutive patients with potentially resectable pancreatic head carcinoma, progn...

To validate abdominal ultrasonography and helical computed tomography in detecting causes for sepsis in patients after abdominal surgery and to determine improved criteria for its use. Eighty-five consecutive surgical patients primarily operated for non-infectious disease were included in this prospective study. Forty-one patients were admitted to...

The aim of this review is to evaluate thrombolytic therapy for acute superior mesenteric artery occlusion as an alternative or adjunctive treatment modality to surgical therapy and to provide current knowledge for timely and informed decisions regarding treatment of acute mesenteric ischemia. A systematic analysis of the available literature from 1...

To analyze the management of delayed massive hemorrhage (DMH) after major pancreatic and biliary surgery. Despite a decreased mortality rate for pancreatic and biliary surgery, DMH is still an important cause of postoperative mortality. The aim of the present study was to analyze the management of DMH after pancreatic and biliary surgery, and speci...

To prospectively evaluate short- and midterm patient preference of computed tomographic (CT) colonography relative to colonoscopy in patients at increased risk for colorectal cancer and to elucidate determinants of preference. Consecutive patients at increased risk for colorectal cancer underwent CT colonography prior to scheduled colonoscopy. Pati...

In a feasibility study, the authors compared polyp detection and interobserver variability at computed tomographic (CT) colonography in 15 patients with doses ranging from medium to very low (12.00-0.05 mSv). At levels down to 2% of the medium dose, the mean detection of polyps 5 mm or larger remained at least 74%, while the number of false-positiv...

To date, computed tomographic (CT) colonography has been compared with an imperfect test, colonoscopy, and has been mainly assessed in patients with positive screening test results or symptoms. Therefore, the available data may not apply to screening of patients with a personal or family history of colorectal polyps or cancer (increased risk). We p...

Previous studies showed that bile duct injury after cholecystectomy is associated with substantial morbidity and a negative effect on Quality of Life. In a recent study, patients with a bile duct injury after cholecystectomy exhibited a 3-fold increase in mortality during a follow-up period of nine years compared to patients without injury. This is...

Diagnostic laparoscopy (DL) combined with laparoscopic ultrasonography (LUS) has previously shown positive results as a staging modality for liver malignancies. Recent improvements in noninvasive diagnostic imaging techniques such as multiphasic spiral computed tomography, together with the policy that bilobar disease or the number of lesions is no...

To retrospectively assess the outcome of transjugular intrahepatic portosystemic shunt (TIPS) placement in a nonselected group of consecutive patients. TIPS placement was attempted in 82 patients. Patients were followed up for at least 3 years according to a standard protocol that included repeated shunt evaluations. Fifty-four patients underwent T...

Previous studies showed that bile duct injury after cholecystectomy is associated with substantial morbidity and a negative effect on Quality of Life. In a recent study, patients with a bile duct injury after cholecystectomy exhibited a 3-fold increase in mortality during a follow-up period of nine years compared to patients without injury. This is...

Voor het beoordelen van een radiologisch onderzoek is het belangrijk dat je een aantal algemene kenmerken controleert (tabel 17.1 voor een conventionele roöntgenfoto en tabel 17.5 voor een CT-scan). Hierna kan de tabel van het betreffende onderzoek stapsgewijs van boven naar beneden worden doorlopen om afwijkingen te achterhalen. Leer jezelf aan om...

Objective. To test the hypothesis that laparoscopic staging in addition to standard radiology staging, improves outcome in patients with peripancreatic carcinoma. To determine if, after laparoscopic staging in patients with irresectable tumours, the hospital-free survival is higher after randomization for endoscopic stent palliation than after surg...

The causes of stress urinary incontinence are not completely known. Recent papers have stressed the importance of more anatomical information, which may help to elucidate the mechanism of stress urinary incontinence. The purpose of this study was to evaluate the prevalence of lesions of the urethral support mechanism and lesions (defects and scars,...

Our objective was to determine the clinical importance of reinterpretation of radiological investigations performed in a referring hospital and the value of additional investigations in a referral centre. A panel of four experts retrospectively evaluated the technical quality of radiological investigations and made reinterpretation reports, of 78 p...

When surgical treatment is being considered for focal nodular hyperplasia, the risk of liver surgery must be carefully balanced against the benefit of resection, especially in the case of a large or centrally located lesion. However, when resection is contraindicated or even impossible, transcatheter arterial embolization should be considered as a...

this article was written were obtained from 12 of 19 institutions that received a request to provide this information. Table 4 lists the scan protocols and the effective doses for these protocols for one CT examination, together with the effective dose of the present study at 100, 50, and 30 mAs. The effective doses at the 12 other centers range fr...

To investigate the sensitivity and specificity of polyp detection and the image quality of computed tomographic (CT) colonography at different radiation dose levels and to study effective doses reported in literature on CT colonography. CT colonography and colonoscopy were performed with 100 mAs in 50 consecutive patients at high risk for colorecta...

Hepatocellular carcinoma (HCC) is often detected at a relatively late stage when tumour size prohibits curative surgery. Screening to detect HCC at an early stage is performed for patients at risk. The aim of this study was to compare prospectively the diagnostic accuracy and classification for management of the two state of the art secondline imag...

Surgery is the treatment of choice in echinococcal cysts with cystobiliary fistulas. PAIR (puncture, aspiration, injection, and reaspiration of scolecidals) is contraindicated in these cases. To evaluate a modified PAIR method for percutaneous treatment of multivesicular echinococcal cysts with or without cystobiliary fistulas which contain non-dra...

The exact location of anovaginal and rectovaginal fistulas cannot be determined by physical examination and conventional techniques. The objective of our study was to compare the accuracy of endoluminal sonography and endoluminal MR imaging in revealing the location of anovaginal and rectovaginal fistulas. Nineteen consecutive patients (age range,...

Objective: The exact location of anovaginal and rectovaginal fistulas cannot be determined by physical examination and conventional techniques. The objective of our study was to compare the accuracy of endoluminal sonography and endoluminal MR imaging in revealing the location of anovaginal and rectovaginal fistulas. Materials and methods: Ninet...

Patients who had a biliary-enteric anastomosis often have elevated liver function tests. The aim of this study was to investigate whether elevated liver function tests are associated with recurrent episodes of cholangitis. Thirty-two patients, who received a biliary-enteric anatomosis for benign biliary disease were evaluated. Follow-up consisted o...

To find out how patients fared after palliative endoscopic biliary drainage for inoperable hilar cholangiocarcinoma. Retrospective study. University hospital, the Netherlands. Between 1992 and 1999, 41 patients who were referred for resection had tumours that were considered unresectable after additional investigations, including an exploratory lap...