Reoperation after antireflux surgery: a population-based cohort study.

BACKGROUND: Antireflux surgery for gastro-oesophageal reflux disease (GORD) and/or hiatal hernia is effective. Between 10 and 20 per cent of patients undergo reoperation for recurrent symptoms. Most studies are undertaken in a single centre and possibly underestimate the rate of reoperation. The aim of this nationwide population-based cohort study was to investigate long-term reoperation rates after antireflux surgery. METHODS: This study included patients who underwent antireflux surgery between 2000 and 2017 in Denmark, and were registered in the Danish nationwide health registries. Reoperation rates were calculated for 1, 5, 10 and 15 years after the primary antireflux operation for GORD and/or hiatal hernia. Duration of hospital stay, 30- and 90-day mortality and morbidity, and use of endoscopic pneumatic dilatation were assessed. RESULTS: This study included a total of 4258 antireflux procedures performed in 3717 patients. Some 3252 patients had only primary antireflux surgery and 465 patients underwent reoperation. The 1-, 5-, 10- and 15-year rates of repeat antireflux surgery were 3·1, 9·3, 11·7 and 12·8 per cent respectively. Thirty- and 90-day mortality rates were similar for primary surgery (0·4 and 0·6 per cent respectively) and reoperations. The complication rate was higher for repeat antireflux surgery (7·0 and 8·3 per cent at 30 and 90 days respectively) than primary operation (3·4 and 4·8 per cent). A total of 391 patients (10·5 per cent of all patients) underwent endoscopic dilatation after primary antireflux surgery, of whom 95 (24·3 per cent) had repeat antireflux surgery. CONCLUSION: In this population-based study in Denmark, the reoperation rate 15 years after antireflux surgery was 12·8 per cent. Reoperations were associated with more complications.

ANTECEDENTES: La cirugía antirreflujo es efectiva en el tratamiento de la enfermedad por reflujo gastroesofágico (gastro-oesophageal reflux disease, GORD) y/o de la hernia de hiato. Entre el 10% y el 20% de los pacientes tienen que ser reoperados por recidiva de los síntomas. La mayoría de los estudios son unicéntricos, lo que posiblemente infravalora la tasa de reintervenciones. El objetivo de este estudio de cohortes de base poblacional nacional fue investigar las tasas de reintervenciones a largo plazo tras la cirugía antirreflujo. MÉTODOS: Este estudio incluyó pacientes sometidos a cirugía antirreflujo entre 2000 y 2017 en Dinamarca y que fueron registrados en los registros nacionales de salud daneses. Se calcularon las tasas de reintervención para 1, 5, 10 y 15 años tras la operación antirreflujo primaria por GORD y/o hernia de hiato. Se evaluaron la duración de la estancia hospitalaria, la morbilidad y mortalidad a 30 y 90 días, y el uso de dilatación neumática endoscópica. RESULTADOS: Este estudio incluyó un total de 4.258 procedimientos antirreflujo efectuados en 3.717 pacientes. Unos 3.252 pacientes fueron sometidos únicamente a cirugía antirreflujo primaria y 465 pacientes a una reintervención. Las tasas de cirugía antirreflujo de revisión a 1, 5, 10 y 15 años fueron del 3,1%, 9,3%, 11,7% y 12,9%, respectivamente. La mortalidad a los 30 y 90 días fue similar cuando se comparó cirugía primaria y reintervenciones (mortalidad a 30 días 0,4% y 90 días 0,6% versus 0% y 0,4%, respectivamente). La tasa de complicaciones fue más elevada para la cirugía antirreflujo de revisión en comparación con la cirugía primaria: tasa de complicaciones a los 30 días 7,0%, 90 días 8,3% versus 30 días 3,4% y 90 días 4,8%, respectivamente. Un total de 391 pacientes (10,5% de todos los pacientes) fueron sometidos a dilatación endoscópica tras la cirugía antirreflujo primaria y 95 de 391 pacientes (24,3%) precisaron cirugía antirreflujo de revisión. CONCLUSIÓN: En este estudio de base poblacional en Dinamarca, la tasa de reintervención a los 15 años tras cirugía antirreflujo fue del 12,9%. Las reintervenciones se asociaron con más complicaciones.

Impact of upper gastrointestinal endoscopic ultrasound in children.

The impact and feasibility of upper gastrointestinal endoscopic ultrasound (EUS) in younger children are unknown. We retrospectively reviewed the EUS procedures we had performed in children younger than 16 years with regard to feasibility, safety, and impact on further treatment. In all, 18 patients (12 boys, 6 girls; median age 12 years, range 0.5-15) underwent EUS. The indications were as follows: tumor (9), epigastric pain (3), recurrent pancreatitis (2), unexplained jaundice (2), hypoglycemia (1), and von Hippel-Lindau disease (1). We concluded that EUS had a significant impact in 78% of the cases. EUS seems to be a safe, feasible, and valuable diagnostic tool.

Combined endoscopic and laparoscopic ultrasound as preoperative assessment of patients with pancreatic cancer.

BACKGROUND: An accurate pre-therapeutic assessment of the resectability in pancreatic cancer patients is essential to reduce the number of futile surgical explorations. The aim of this study was to assess the combination of endoscopic ultrasound (EUS) and laparoscopic ultrasound (LUS) regarding the detection of patients with non-resectable tumours. PATIENTS AND METHODS: From 2002 to 2004, 179 consecutive patients with pancreatic cancer referred for surgical treatment were eligible. Thirty-one (17%) patients were excluded due to co-morbidity and poor performance status. Two patients (1%) were excluded due to metastasis seen on CT scans prior to referral. Thus, 146 patients entered the study. Patients were first examined with EUS followed by LUS, if EUS found no signs of non-resectability. Only patients with tumours found to be resectable or possibly resectable at EUS and LUS were offered surgical treatment. Resectability criteria were defined prior to the study. RESULTS: In all, 108 (74%) patients had non-resectable tumours by the pre-defined criteria. EUS identified 68 (63%) patients and LUS identified an additional 26 (24%) patients. Thus, a total of 94 (87%) patients were non-resectable at either EUS or LUS. Fifty-two (36%) patients underwent surgery. Six patients had surgical exploration and three patients had palliative surgery. Forty-three patients (29%) were resected with curative intention, of whom 38 (88%) had an R0 resection and 5 (12%) had a palliative resection. DISCUSSION: The combination of EUS and LUS is accurate in identifying the non-resectable patients and has a high predictive value for complete resection.

Prospective evaluation of patient tolerability, satisfaction with patient information, and complications in endoscopic ultrasonography.

BACKGROUND AND STUDY AIMS: Prospective data are lacking on the safety of endoscopic ultrasonography (EUS) and on patient satisfaction with the procedure. We prospectively recorded complications related to EUS in order to establish morbidity and mortality. In addition the levels of patient satisfaction were evaluated, with regard to the tolerability of the procedure (pain, discomfort, and anxiety levels) and the provision of information. PATIENTS AND METHODS: 3324 consecutive patients who underwent EUS were studied with regard to complications. During the study period 300 patients were interviewed and followed up in detail as part of the evaluation of patient satisfaction. RESULTS: Ten patients (0.3 %) suffered from a complication related to the EUS procedure, and two patients died (0.06 %). There were no significant differences between the complication rates for EUS-guided fine-needle aspiration (EUS-FNA) and for EUS, but both fatal cases related to EUS-FNA/EUS-guided intervention. Nine of the ten patients with complications (90 %) had a diagnosis of malignancy, and esophageal perforation accounted for half of all complications. Although the majority of patients with nonlethal complications were managed well on conservative regimens, only one case, of self-limiting acute pancreatitis, could be classified as a mild complication. With regard to patient tolerability, only minor incidents occurred during the EUS procedure (tracheal suction 5 %, vomiting 0.3 %, aspiration 0.3 %) and no intervention was necessary. During the procedure, 80 % of the patients had no or only slight pain and more than 95 % experienced only slight or no anxiety, whereas more than half of the patients experienced moderate to severe discomfort. More than 90 % of the patients were satisfied or very satisfied with the information provided to them before and after the EUS, and the same number of patients were ready without hesitation to undergo an additional EUS examination if necessary. CONCLUSIONS: EUS, EUS-FNA and EUS-guided intervention are safe techniques, but severe and lethal complications do occur. The EUS procedures can be performed with a high level of patient satisfaction and with low levels of pain, discomfort and anxiety.

Cost-effectiveness of endoscopic ultrasonography, magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography in patients suspected of pancreaticobiliary disease.

BACKGROUND: It is not known whether initial endoscopic ultrasonography (EUS) or magnetic resonance cholangiopancreatography (MRCP) is more cost effective than endoscopic retrograde cholangiopancreatography (ERCP). METHODS: A cost-effectiveness analysis of EUS, MRCP and ERCP was performed on 163 patients. The effectiveness of an investigation was defined as the percentage of patients with no need for further evaluation after the investigation in question had been performed. Costs were assumed from the budget-holder's point of view. RESULTS: MRCP, EUS and ERCP had a total accuracy of 0.91, 0.93 and 0.92, respectively. Eighty-four (52%) patients needed endoscopic therapy in combination with ERCP, giving an effectiveness of MRCP, EUS, and ERCP of 0.44, 0.45 and 0.92, respectively. The cost-effectiveness of MRCP, EUS, and ERCP was 6622, 7353 and 4246 Danish Kroner (DKK) per fully investigated and treated patient (1 DKK=0.14 EUR). CONCLUSION: Within a patient population with a probability of therapeutic ERCP in 50% of the patients, ERCP was the most cost-effective strategy.

A new method for three-dimensional laparoscopic ultrasound model reconstruction.

BACKGROUND: Laparoscopic ultrasound is an important modality in the staging of gastrointestinal tumors. Correct staging depends on good spatial understanding of the regional tumor infiltration. Three-dimensional (3D) models may facilitate the evaluation of tumor infiltration. The aim of the study was to perform a volumetric test and a clinical feasibility test of a new 3D method using standard laparoscopic ultrasound equipment. METHODS: Three-dimensional models were reconstructed from a series of two-dimensional ultrasound images using either electromagnetic tracking or a new 3D method. The volumetric accuracy of the new method was tested ex vivo, and the clinical feasibility was tested on a small series of patients. RESULTS: Both electromagnetic tracked reconstructions and the new 3D method gave good volumetric information with no significant difference. Clinical use of the new 3D method showed accurate models comparable to findings at surgery and pathology. CONCLUSIONS: The use of the new 3D method is technically feasible, and its volumetrically, accurate compared to 3D with electromagnetic tracking.

Is there a difference in diagnostic accuracy and clinical impact between endoscopic ultrasonography and magnetic resonance cholangiopancreatography?

BACKGROUND AND STUDY AIMS: It is still unknown whether there is a difference in diagnostic accuracy and clinical impact between endoscopic ultrasonography (EUS) and magnetic resonance cholangiopancreatography (MRCP). PATIENTS AND METHODS: The test performance and potential clinical impact of EUS and MRCP, had each investigation been performed as the first examination method, were compared prospectively in 163 patients admitted for and examined by endoscopic retrograde cholangiopancreatography (ERCP). RESULTS: The accuracies of EUS and MRCP were 0.93 and 0.91, respectively (no significant difference, P > 0.05). Had EUS or MRCP been performed as the first investigation in the 75 patients who had a presumed high probability for needing therapeutic ERCP, only 15 and nine patients, respectively, would have avoided ERCP. In this group of patients, one patient needed other diagnostic investigations following EUS compared with 11 patients following MRCP ( P = 0.004). For the 57 patients with an intermediate probability of needing endoscopic therapy, EUS and MRCP would have spared 37 and 38 patients, respectively, from the need to have an ERCP. In 31 patients with a presumed low risk of needing endoscopic therapy, 30 and 29 patients would have been spared from ERCP had EUS and MRCP, respectively, been performed initially. CONCLUSIONS: There was no difference in the diagnostic accuracy and clinical impact between EUS and MRCP in the majority of the patients. The impact of EUS or MRCP on the ERCP workload was highly dependent on the presumed probability of needing endoscopic therapy.

Clinical impact of endoscopic ultrasonography at a county hospital.

BACKGROUND AND STUDY AIMS: Although endoscopic ultrasonography (EUS) is a well-described examination method, there have been few reports concerning its clinical impact. The aim of this study was to describe EUS as it is performed at a county hospital, with an emphasis on the indications and clinical outcome. PATIENTS AND METHODS: Patients examined using EUS between December 1997 and November 2000 were recorded prospectively. Follow-up was conducted by examining each patient's medical records at least 3 months after the investigation. The EUS findings were compared with the patient's final diagnosis, and the decisions made by the referring department on the basis of each investigation were recorded. RESULTS: A total of 344 EUS procedures were performed. In the third year, the distribution of patients relative to the various referral diagnoses was: 78 with suspected benign pancreaticobiliary disease, 33 for staging of known upper gastrointestinal tract malignancy, 15 with suspected mediastinal disease or for staging of lung cancer, 13 with suspected submucosal lesions, and five with unclassified disease. Follow-up was possible in 340 patients (99 %). Compared to the final diagnosis in each patient, the sensitivity, specificity, and accuracy rates of EUS were 86 %, 90 %, and 88 %, respectively. The EUS findings made more invasive procedures unnecessary in 199 patients (58 %). EUS led to a switch to less invasive procedures in 61 patients (18 %), and it had no influence on the further management strategy in 80 patients (24 %). CONCLUSIONS: EUS has a high level of accuracy and a substantial clinical impact when performed in an unselected population. The estimated numbers of investigations needed appear to justify setting up an EUS center at institutions with a catchment population of 350 000 inhabitants.

Initial experience with new dedicated needles for laparoscopic ultrasound-guided fine-needle aspiration and histological biopsies.

BACKGROUND AND STUDY AIMS: Laparoscopic ultrasonography (LUS) is an important imaging modality during laparoscopic staging of intra-abdominal malignancies, but LUS-assisted biopsy is often difficult or impossible. We report a newly developed inbuilt biopsy system for direct LUS-guided fine-needle aspiration (FNA) and Tru-cut biopsies. PATIENTS AND METHODS: LUS-guided biopsy was performed in 20 patients with upper gastrointestinal tract tumors. The biopsied lesions had either not been previously detected by other imaging modalities or had been inaccessible, or the biopsy sample had been inadequate. Primary diagnosis, duration of biopsy procedure, needle monitoring (visibility, penetration, and deviation), complications, technical failures, and pathological findings were prospectively recorded. RESULTS: 44 biopsies were performed with 25 needles (19, 20, and 22-G). Needle monitoring and penetration were good or acceptable in 18 patients (90%). Slight needle deviation (<10 mm) was seen in eight patients (40%). The LUS-guided biopsy specimen was sufficient for analysis in 13 patients (65%). In two additional patients, adequate material was obtained, but pathological examination was impossible owing to incorrect handling of the specimen. The biopsy procedures lasted 16.3 minutes (range 10-20 minutes) and no complications were seen. CONCLUSIONS: LUS-guided fine-needle aspiration or Trucut biopsy is possible using this newly developed biopsy system. These preliminary data suggest that LUS-guided biopsy may further improve the diagnostic possibilities of LUS.

Clinical impact of endoscopic ultrasound-guided fine needle aspiration biopsy in patients with upper gastrointestinal tract malignancies. A prospective study.

BACKGROUND AND STUDY AIMS: Several studies have evaluated the accuracy of endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) in the upper gastrointestinal tract, but so far no studies have specifically evaluated the clinical impact of EUS-FNAB in upper gastrointestinal tract cancer patients. In this consecutive and prospective study, EUS-FNAB was only performed if a positive malignant finding would change the therapeutic strategy. PATIENTS AND METHODS: Between 1997 and 1999, 307 consecutive patients were referred for EUS with a diagnosis or strong suspicion of esophageal, gastric or pancreatic cancer; 274 patients were potential candidates for surgical treatment and had EUS. According to predefined impact criteria, 27% (75/274) of the patients had EUS-FNAB for staging or diagnostic reasons. RESULTS: The overall clinical impact of EUS-FNAB was 13%, 14%, and 30% in esophageal, gastric, and pancreatic cancer, respectively. The staging-related clinical impact was similar for all three types of cancer (11-12.5%), whereas the diagnosis-related impact was highest in pancreatic cancer patients (86%). EUS-FNAB was inadequate in 13% and gave false-negative results in 5%. The overall sensitivity, specificity and accuracy for EUS-FNAB were 80%, 78% and 80%, respectively. No complications related to the biopsy procedure were seen. CONCLUSIONS: If EUS-FNAB was performed only in cases where a positive malignant result would change patient management, then approximately one out of four patients with upper gastrointestinal tract cancer would require a biopsy. With this approach the actual clinical impact of EUS-FNAB ranged from 13% in esophageal cancer to 30% in pancreatic cancer. EUS-FNAB plays a limited, but very important clinical role in the assessment of upper gastrointestinal tract cancer.

An analysis of the conformational paths of citrate synthase.

Previous simulation studies have provided reaction pathways leading from the closed to the open form of citrate synthase. We now undertake a detailed analysis of these pathways using a variety of different tools including backbone dihedral angles, P-Curves helicoidal parameters, inter-helix geometrical parameters, and accessibility calculations. The results point to a relatively small number of residues, mostly in loop regions, which are responsible for the majority of the conformational changes observed. An important role is attributed to transient changes in the backbone which facilitate movement along the reaction coordinate. Comparisons between the two pathways show that they share many common features despite the different algorithms used to generate them.

Theoretical determination of conformational paths in citrate synthase.

Two methods are developed for the theoretical determination of a conformational path between two well-documented forms, a closed form and the open form [Remington et al. (1982) J. Mol. Biol. 158, 111-152] of pig heart citrate synthase, a dimeric enzyme of 2 x 437 residues. The first method uses the minimization of the sum of the potential energies at a set of equidistant points, according to Elber and Karplus [(1987) Chem. Phys. Lett. 139, 375-380]. The initialization of the algorithm is modified to account for large-angle rotations of many groups by performing the interpolations in the space of internal polar coordinates of a set of generalized Jacobi vectors earlier introduced by Durup [(1991) J. Phys. Chem. 95, 1817-1829] and by carefully testing all choices of directions of rotation for determining the initialized midpoint between the known forms. The path includes intermediate points, created by successive splittings of each interval into two equal parts, with a partial energy minimization performed after each splitting. The minimization encounters the well-known local-minima problem, which here is handled by low-temperature molecular dynamics annealing. It is shown that the best ratio of potential energy decrease to rms deviation is achieved by running the dynamics at 50 K, as compared to 100 K and above. The main character of the path obtained is the occurrence of strong to-and-fro variations of some dihedral angles at specific stages along the path. The second method, which we name directed dynamics, uses only low-temperature molecular dynamics simulations by starting trajectories from each of the two known forms with initial velocities directed toward the other one. The procedure is iterated by restarting trajectory pairs after the points of closest approach of the preceding pair. The two half-paths thus built eventually meet after 70 iterations. This method provides a second path with strong similarities, as well as some differences, with respect to the path obtained by the first method.