Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

11 Convergence insufficiency: are we making a difference in patients' lives or is it a waste of time!

Convergence insufficiency (CI) is a common condition that can impair visual performance and comfort during close visual work. This prospective study evaluated the effectiveness of interventions on clinical outcomes and quality-of-life using the adult strabismus quality-of-life questionnaire (AS20) in patients with CI.Data was extracted from a database collected at first consultation from 2015 to 2022. Demographics, interventions and outcomes of 84 patients with CI (mean age 47.0±24.9 years) were analysed.Orthoptic exercises were prescribed to 56% of patients, 32% received prisms, 15% received no treatment, with 3 discharged on the same day. At latest follow-up review, 22.6% were recommended to continue exercises, 28.6% had prisms, 1 underwent bimedial resection and 2 had botox. The median follow-up was 5.5(5.0-55)months, 88.1% were discharged with 29.8% following failure to attend and 9.5% deceased. Near-point of convergence (NPC) improved from a median of 15(6-50)cm to 10(6-30)cm. The median AS20 score at presentation were 100(30-100) and 47.5(0-100), and post-intervention were 100(80-100) and 77.5(12.5-97.5) for psychosocial and functional components, respectively.At the latest follow-up, the attendance failure rate was higher for exercises (36%) than for prisms (15%). Improvement was noted in NPC (33%) and mean AS20 scores was 9% higher psychosocially and 32.8% functionally, highlighting the benefits of intervention on patients' quality-of-life.This cohort provides valuable insights into the clinical management of CI, as evidenced by improvements in NPC and AS20 scores. However, the study also found that long-term compliance with treatment is intrinsically challenging, emphasising the importance of disease education.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

Simulations of wavelength-multiplexed holography for single-shot spatiotemporal characterization of NIF's advanced radiographic capability (ARC) laser

We simulate the use of a newly developed single-shot wavelength-multiplexed holography-based diagnostic, STRIPED FISH, to fully characterize the as-delivered laser pulses of the National Ignition Facility's Advanced Radiographic Capability (NIF-ARC) laser. To that end, we have performed simulations of the NIF-ARC pulse incorporating (a) a time-integrated spatial-profile measurement and a complete temporal-intensity-and-phase measurement using a frequency resolved optical gating, but without any spatiotemporal pulse characterizations, and (b) simulated first-order spatiotemporal distortions, which could be measured on a single shot if a STRIPED FISH device were deployed.

Prescribing patterns and outcomes of venous thromboembolism prophylaxis in hospitalized medical and cancer patients: Observations from the Ottawa Hospital

Guidelines suggest broad use of pharmacologic prophylaxis to prevent venous thromboembolism (VTE) in hospitalized medical patients, however little 'real-world' data exists to support this. Our goal was to describe the use of thromboprophylaxis among general medical and cancer patients admitted to hospital, compare VTE and bleeding outcomes according to use of thromboprophylaxis, and to determine what variables influence prescribing patterns and outcomes. Patients admitted to the general medical and oncology services at The Ottawa Hospital between 2010 and 2015 were retrospectively reviewed and classified according to whether they received initial, delayed, or no pharmacologic thromboprophylaxis during their first hospitalization. Patients with an alternate indication for anticoagulation or those admitted with a bleeding event were excluded from analysis. The primary efficacy outcome was any symptomatic VTE during index hospitalization or within 90 days of discharge, and the primary safety outcome was clinically relevant bleeding during the index hospitalization. 17,262 patients were included in our final analysis. General medical patients selected to receive no, initial, or delayed thromboprophylaxis had 0.4%, 0.7%, and 2.4% rates of VTE; and 0.2%, 0.7%, and 1.5% rates of clinically relevant bleeding complications, respectively. Cancer patients had significantly higher rates of VTE: 3.3%, 3.9%, and 5.0%; and 0.9%, 0.7%, and 3.0% rates of clinically relevant bleeding among those selected to receive no, initial, or delayed thromboprophylaxis, respectively. Overall, our study suggests that broad use of pharmacologic thromboprophylaxis may be unnecessary in select low-risk general medical patients and may be less effective in cancer patients in whom new studies are indicated.

Development of a patient decision aid for treatment resistant depression

BACKGROUND

Shared decision-making (SDM) involves patients and clinicians choosing treatment jointly. SDM in mental health is hampered by lack of well-developed supporting tools. We describe an evidence-based patient decision aid (PDA) to facilitate SDM for treatment-resistant depression (TRD) following US National Quality Forum standards which are based upon the International Patient Decision Aid Standards (IPDAS).

METHODS

A web-based PDA was developed by a multidisciplinary steering committee of clinicians, patient advocates, patients and a decision scientist. Development included creating content consistent with decision-making domains that are impacted by patient preference in TRD. Development was guided by literature review, group conference calls/discussions, patient and clinician interviews (N = 8), high and lower literacy focus groups (N = 11) and pilot study (N = 5). The PDA presents risk-benefit information on domains (e.g., effectiveness, mode of administration, side effects, cost) and includes values clarification exercises. Pilot study patients were administered the Decisional Conflict Scale (DCS) and Decision Self-Efficacy Scale (DSES) prior to and following PDA interaction and clinician SDM.

RESULTS

During the pilot, prior to PDA interaction, mean (standard deviation) DCS score was 42.2 (14.4) and DSES score was 86.0 (14.6) out of 100. Following PDA interaction and SDM, DCS decreased (improved) to 28.1 (SD 4.1) and DSES increased to 95.5 (6.7). All patients endorsed that the PDA helped them to: recognize pros and cons of options; understand how treatments were administered, possible side-effects, and likelihood of benefit; recognize what was important relative to the decision; organize thoughts and prepare for a discussion with their clinician.

CONCLUSIONS

This PDA may support SDM in TRD. A future trial to determine impact of the present SMD on decision-making quality is warranted. It also highlights gaps in comparative effectiveness trials that could guide equitable shared decision-making.

Validating data analysis of broadband laser ranging

Broadband laser ranging combines spectral interferometry and a dispersive Fourier transform to achieve high-repetition-rate measurements of the position of a moving surface. Telecommunications fiber is a convenient tool for generating the large linear dispersions required for a dispersive Fourier transform, but standard fiber also has higher-order dispersion that distorts the Fourier transform. Imperfections in the dispersive Fourier transform significantly complicate the ranging signal and must be dealt with to make high-precision measurements. We describe in detail an analysis process for interpreting ranging data when standard telecommunications fiber is used to perform an imperfect dispersive Fourier transform. This analysis process is experimentally validated over a 27-cm scan of static positions, showing an accuracy of 50 μm and a root-mean-square precision of 4.7 μm.

How to undertake a research project and write a scientific paper

Research and publishing are essential aspects of lifelong learning in a surgical career. Many surgeons, especially those in training, ask for guidance on how they might start a simple project that may lead to a publication. This short paper offers some practical guidelines on the subject.

How to undertake a research project and write a scientific paper

Research and publishing are essential aspects of lifelong learning in a surgical career. Many surgeons, especially those in training, ask for guidance on how they might start a simple project that may lead to a publication. This short paper offers some practical guidelines on the subject.

Can the rat be used as a valid model of human esophageal adenocarcinoma?

Animal models of Barrett's metaplasia and esophageal adenocarcinoma are important to further characterize the disease and test potential therapies. This paper reviews the development of the surgical model of esophageal adenocarcinoma in the rat and considers whether this model provides a biologically accurate representation of Barrett's esophagus and esophageal adenocarcinoma in humans.

Comparison of laparoscopic and open pyeloplasty in 100 patients with pelvi-ureteric junction obstruction

BACKGROUND

This study aimed to determine whether the morbidity and outcome rates for laparoscopic transperitoneal dismembered pyeloplasty are different from those for dismembered pyeloplasty, to analyze the learning curve of laparoscopic pyeloplasty, and to determine whether preoperative stent placement affects outcome.

METHODS

For this study, 49 laparoscopic pyeloplasties (period 2000-2005) and 51 open pyeloplasties (period 1992-2003) were reviewed.

RESULTS

Compared with open procedures, laparoscopic procedures were associated with a longer mean operating time (159 vs 91 min; p < 0.001), a shorter mean time to normal diet (38 vs 72 h; p < 0.001), and a similar mean hospital stay (5 days; p = 0.6). The operative complication rates were 17% for primary laparoscopic pyeloplasties and 24% for primary open pyeloplasties. The rates were higher for secondary procedures. The success rates for primary and secondary procedures were, respectively, 98% (41/42) and 57% (4/7) for laparoscopy and 96% (46/48) and 67% (2/3) for open surgery. Failed procedures showed no improvement in loin pain or obstruction. At the 6-month follow-up evaluation, 29% of the open surgery patients but none of the laparoscopic surgery patients reported wound pain.

CONCLUSIONS

The efficacy of laparoscopic pyeloplasty is equivalent to that of open pyeloplasty, with less wound pain at 6 months. The outcome for secondary procedures is inferior. There was a trend toward a reduction in complications and the conversion rates with time, suggesting that there may be a learning curve of approximately 30 laparoscopic pyeloplasty cases. Preoperative stent insertion did not seem to affect any objective measures of outcome for laparoscopic pyeloplasty.

Laparoscopic splenectomy: the clinical practice guidelines of the European Association for Endoscopic Surgery (EAES)

BACKGROUND

Although laparoscopic splenectomy (LS) has become the standard approach for most splenectomy cases, some areas still remain controversial. To date, the indications that preclude laparoscopic splenectomy are not clearly defined. In view of this, the European Association for Endoscopic Surgery (EAES) has developed clinical practice guidelines for LS.

METHODS

An international expert panel was invited to appraise the current literature and to develop evidence-based recommendations. A consensus development conference using a nominal group process convened in May 2007. Its recommendations were presented at the annual EAES congress in Athens, Greece, on 5 July 2007 for discussion and further input. After a further Delphi process between the experts, the final recommendations were agreed upon.

RESULTS

Laparoscopic splenectomy is indicated for most benign and malignant hematologic diseases independently of the patient's age and body weight. Preoperative investigation is recommended for obtaining information on spleen size and volume as well as the presence of accessory splenic tissue. Preoperative vaccination against meningococcal, pneumococcal, and Haemophilus influenzae type B infections is recommended in elective cases. Perioperative anticoagulant prophylaxis with subcutaneous heparin should be administered to all patients and prolonged anticoagulant prophylaxis to high-risk patients. The choice of approach (supine [anterior], semilateral or lateral) is left to the surgeon's preference and concomitant conditions. In cases of massive splenomegaly, the hand-assisted technique should be considered to avoid conversion to open surgery and to reduce complication rates. The expert panel still considered portal hypertension and major medical comorbidities as contraindications to LS.

CONCLUSION

Despite a lack of level 1 evidence, LS is a safe and advantageous procedure in experienced hands that has displaced open surgery for almost all indications. To support the clinical evidence, further randomized controlled trials on different issues are mandatory.

Volume and outcome for major upper GI surgery in England

BACKGROUND

The correlation between hospital or surgeon volume and outcome for complex surgical procedures has been the subject of several studies in recent years. In the UK, such studies have been used to strengthen the case for centralization of such procedures. The recent availability of easily accessible and fully independent data on hospital outcomes for surgical services in the UK has provided the opportunity to review any potential associations between volume and outcome in the UK.

METHODS

Hospital Episode Statistic (HES) data were collected through Dr Foster for four different upper GI procedures (gastrectomy, esophagectomy, pancreaticoduodenectomy, and liver resection) for a 6-year period from 1999 to 2005. Data for each procedure were divided into volume-dependant quartiles to assess any differences in mortality outcome.

RESULTS

Generally, mortality rates for all four procedures are lower than previously studies have suggested. A significant trend favoring high volume providers was noted for esophagectomy, with mortality rates varying from 7.8% to 4.0% for lowest to highest volume providers (p < 0.001). A similar but less clear-cut trend was noted for pancreaticoduodenectomy. There was no significant difference for gastric and liver resection between low- and high-volume providers. There was a 20% decrease in centers performing esophagectomy and 28% for centers performing pancreaticoduodenectomy.

CONCLUSION

There is a volume outcome association for esophagectomy and pancreaticoduodenectomy. There is no association for gastrectomy or hepatectomy.

Development of a food frequency questionnaire for the assessment of quercetin and naringenin intake

OBJECTIVES

To measure the relationship between quercetin and naringenin intakes as estimated by food frequency questionnaire (FFQ), and the urinary excretion of quercetin and naringenin aglycones after their enzymatic hydrolysis in human volunteers.

SUBJECTS AND METHODS

Volunteers were recruited via the Human Nutrition Unit volunteer databank at the Institute of Food Research, Norwich. Sixty-three volunteers were recruited into the study, of which 14 were excluded and 49 completed the study. A modified FFQ was developed and used to estimate daily intake of quercetin and naringenin in 49 healthy volunteers who also provided five 24-h urine samples over a 2-week period. Urinary excretion of quercetin and naringenin metabolites was determined by solid-phase extraction and high-pressure liquid chromatography.

RESULTS

The estimated mean intakes of quercetin and naringenin were 29.4 mg (s.d. 15.0) and 58.1 mg (s.d. 62.7) per day, respectively. Mean urinary excretion of quercetin was 60.1 microg (s.d. 33.1) and that of naringenin was 0.56 mg (s.d. 0.4). The correlation between FFQ estimated intake of quercetin and naringenin and levels excreted in the urine were r=0.82 (P<0.0001) and r=0.25 (P=0.05), respectively.

CONCLUSIONS

We observed a statistically significant correlation between the urinary excretion of quercetin and naringenin metabolites and their dietary intake as estimated by FFQ. Use of FFQs in epidemiological studies requiring an estimate of flavonoid intake seems justified.

Who should perform laparoscopic cholecystectomy? A 10-year audit

BACKGROUND

Laparoscopic cholecystectomy is one of the most common operations in general surgery. It is performed by surgeons with a specialist interest in biliary disease as well as by surgeons with other specialist interests.

METHODS

This retrospective audit of all cholecystectomies was conducted in a single hospital over a 10-year period from 1996 to 2005. Data were extracted from two independent electronic databases and supplemented by a full note review of cases with extended postoperative stay or unplanned readmission. The outcomes for cases under the care of specialist upper gastrointestinal (GI) consultants were compared with outcomes for cases of general surgery consultants from other firms.

RESULTS

Data from 4,139 cholecystectomies were obtained. More cholecystectomies performed by upper GI firms were completed laparoscopically (96.2% vs 80.1%) with a higher rate of intraoperative cholangiograms (83.4% vs 16.9%). The mean operating time was shorter for upper GI cases (69 vs 84 min), as was the postoperative hospital stay (2 vs 3.6 days). There also was a significantly lower incidence of bile duct injury in upper GI cases (0.1% vs 0.9%).

CONCLUSION

In their institution, the authors found evidence of improved outcomes when laparoscopic cholecystectomy was performed under the care of surgeons with a specialist interest in upper GI or hepatopancreaticobiliary surgery.

Evolution of Mycobacterium ulcerans and other mycolactone-producing mycobacteria from a common Mycobacterium marinum progenitor

It had been assumed that production of the cytotoxic polyketide mycolactone was strictly associated with Mycobacterium ulcerans, the causative agent of Buruli ulcer. However, a recent study has uncovered a broader distribution of mycolactone-producing mycobacteria (MPM) that includes mycobacteria cultured from diseased fish and frogs in the United States and from diseased fish in the Red and Mediterranean Seas. All of these mycobacteria contain versions of the M. ulcerans pMUM plasmid, produce mycolactones, and show a high degree of genetic relatedness to both M. ulcerans and Mycobacterium marinum. Here, we show by multiple genetic methods, including multilocus sequence analysis and DNA-DNA hybridization, that all MPM have evolved from a common M. marinum progenitor to form a genetically cohesive group among a more diverse assemblage of M. marinum strains. Like M. ulcerans, the fish and frog MPM show multiple copies of the insertion sequence IS2404. Comparisons of pMUM and chromosomal gene sequences demonstrate that plasmid acquisition and the subsequent ability to produce mycolactone were probably the key drivers of speciation. Ongoing evolution among MPM has since produced at least two genetically distinct ecotypes that can be broadly divided into those typically causing disease in ectotherms (but also having a high zoonotic potential) and those causing disease in endotherms, such as humans.

Systematic review: Cyclo-oxygenase-2 in human oesophageal adenocarcinogenesis

BACKGROUND

Published in vitro and animal in vivo studies have demonstrated that cyclo-oxygenase-2 plays an important role during oesophageal adenocarcinogenesis. However, the extent to which these studies are directly relevant to events in the human lower oesophagus is questionable.

AIM

To perform a systematic review of all available human studies that have evaluated levels of cyclo-oxygenase-2 expression during the progression from Barrett's metaplasia to oesophageal adenocarcinoma.

METHODS

A literature search was performed to identify all studies which qualitatively or quantitatively assessed cyclo-oxygenase-2 protein or gene expression in either Barrett's, dysplastic or adenocarcinoma tissue in humans.

RESULTS

A total of 27 studies met the inclusion criteria. There was general agreement that cyclo-oxygenase-2 was either absent or very weakly expressed in normal oesophageal squamous mucosa, but considerable disagreement regarding the presence of cyclo-oxygenase-2 in Barrett's and low-grade dysplasia. All studies agreed that high-grade dysplasia and adenocarcinoma expressed cyclo-oxygenase-2 to some extent although levels varied considerably between tissue samples.

CONCLUSIONS

There is conflicting evidence in the literature for cyclo-oxygenase-2 playing an important role in early oesophageal adenocarcinogenesis. Other non-cyclo-oxygenase-2 targets may account for the epidemiological data supporting the use of non-steroidal anti-inflammatory drugs in the chemoprevention of oesophageal adenocarcinoma.

Globally distributed mycobacterial fish pathogens produce a novel plasmid-encoded toxic macrolide, mycolactone F

Mycobacterium ulcerans and Mycobacterium marinum are closely related pathogens which share an aquatic environment. The pathogenesis of these organisms in humans is limited by their inability to grow above 35 degrees C. M. marinum causes systemic disease in fish but produces localized skin infections in humans. M. ulcerans causes Buruli ulcer, a severe human skin lesion. At the molecular level, M. ulcerans is distinguished from M. marinum by the presence of a virulence plasmid which encodes a macrolide toxin, mycolactone, as well as by hundreds of insertion sequences, particularly IS2404. There has been a global increase in reports of fish mycobacteriosis. An unusual clade of M. marinum has been reported from fish in the Red and Mediterranean Seas and a new mycobacterial species, Mycobacterium pseudoshottsii, has been cultured from fish in the Chesapeake Bay, United States. We have discovered that both groups of fish pathogens produce a unique mycolactone toxin, mycolactone F. Mycolactone F is the smallest mycolactone (molecular weight, 700) yet identified. The core lactone structure of mycolactone F is identical to that of M. ulcerans mycolactones, but a unique side chain structure is present. Mycolactone F produces apoptosis and necrosis on cultured cells but is less potent than M. ulcerans mycolactones. Both groups of fish pathogens contain IS2404. In contrast to M. ulcerans and conventional M. marinum, mycolactone F-producing mycobacteria are incapable of growth at above 30 degrees C. This fact is likely to limit their virulence for humans. However, such isolates may provide a reservoir for horizontal transfer of the mycolactone plasmid in aquatic environments.

Does open surgery continue to have a role in elective splenectomy?

BACKGROUND

Since it was first reported in 1991, laparoscopic splenectomy has become the procedure of choice for elective splenectomy. However, doubts have been raised regarding the suitability of patients with splenomegaly (>1 kg) for laparoscopic resection because there have been reports of greater morbidity and higher conversion rates in this group of patients. Since 2000, patients referred to the authors' center for splenectomy with an estimated spleen weight exceeding 1 kg have undergone splenectomy by the open approach.

METHODS

Between September 1995 and April 2005, 95 elective splenectomies were performed by a single surgeon. Operative data were collected prospectively.

RESULTS

A comparison between the operations that took place before 2001 (n = 47) and those performed after 2000 (n = 48) for all sizes of spleen showed significant reductions in conversion rate, operative time, and hospital stay in the later group. As compared with laparoscopic splenectomy (n = 11), open splenectomy (n = 18) for cases of splenomegaly resulted in a significantly shorter operative time, less operative blood loss, and no significant difference in hospital stay.

CONCLUSION

Although laparoscopic splenectomy is the treatment of choice for the majority of patients requiring elective splenectomy, the procedure for patients with significant splenomegaly requires caution and common sense. This study shows that an open splenectomy for these patients significantly reduces operative time and blood loss without increasing morbidity or hospital stay.

Endoscopy waiting times and impact of the two week wait scheme on diagnosis and outcome of upper gastrointestinal cancer

The NHS has introduced the two week wait scheme to detect upper gastrointestinal cancers at an early stage and improve survival rates The aim of this study was to assess the impact of this scheme and changes in endoscopy waiting times on tumour stage and resection rates over a four year period. Data were analysed prospectively for all patients diagnosed with oesophagogastric cancer between September 1998 and September 2002 and from those referred under the two week wait scheme since its introduction in 2000. Of those tumours diagnosed by this scheme (15%) only 5% were early disease (stage 1 or 2). Patients with early cancer, mainly diagnosed by routine gastroscopy, do not present with symptoms meeting the two week wait criteria. An increase in the resection rates for early disease will most probably be seen with a reduction in routine endoscopy waiting times.

Prospective randomized trial of laparoscopic gastrojejunostomy versus duodenal stenting for malignant gastric outflow obstruction

BACKGROUND

We prospectively compared laparoscopic gastrojejunostomy with duodenal stenting as a means of palliating malignant gastric outflow obstruction.

METHODS

A total of 27 patients with malignant gastric outflow obstruction were randomized to either laparoscopic gastrojejunostomy (LGJ) or duodenal stenting (DS) over a 3-year period.

RESULTS

Thirteen patients underwent successful LGJ and 10 had successful DS. Eight patients had complications after LGJ, but none had complications after DS. Patients who underwent LGJ had a significant increase in visual analog pain score at day 1 (p = 0.05), and also had a longer hospital stay compared to those who underwent DS (11.4 vs. 5.2 days, p = 0.02). After DS, patients experienced an improvement in physical health at 1 month as measured using the Short Form-36 (SF-36) questionnaire (p < 0.01). There was no change following LGJ.

CONCLUSION

Duodenal stenting is a safe means of palliating malignant gastric outflow obstruction. It offers significant advantages for patients compared with minimal-access surgery.

Systematic review: the chemoprevention of oesophageal adenocarcinoma

The incidence of oesophageal adenocarcinoma is increasing in the UK faster than any other malignancy. Despite its relatively poor prognosis and the limited success of existing treatments, there is enthusiasm that chemopreventive agents might be able to stem the transition from normal squamous epithelium to adenocarcinoma. We discuss gastro-oesophageal reflux as the main risk factor for the development of Barrett's metaplasia, the only known precursor of oesophageal adenocarcinoma. Treatment options for reflux disease are considered with regard to their effects on cancer risk. Recent advances in the molecular and cell biology of Barrett's are outlined, and potential targets for chemoprevention examined. Available treatments for reflux disease have not convincingly altered the likelihood of cancer development. Epidemiological and animal studies support the use of non-steroidal anti-inflammatory drugs as potential chemopreventive agents. Dietary agents, however, have a more favourable side-effect profile and may prove to be an attractive alternative, although more work is needed to fully explore this prospect.

Changes in functional gastrointestinal symptoms as a result of antireflux surgery

BACKGROUND

This study identifies how functional symptoms are altered after antireflux surgery and whether there are any predictors of such change.

METHODS

A total of 206 patients underwent successful laparoscopic Nissen fundoplication. A questionnaire was sent at a median of 4.3 years (range = 0.3-8.4) after fundoplication. Patients were asked to provide scores for reflux and functional symptoms that were experienced prior to surgery and at the time of the questionnaire.

RESULTS

Eighty-one percent of patients responded. Scores for heartburn, regurgitation, and difficulty swallowing were felt to have significantly improved (p < 0.01). Flatulence was the only functional symptom to have significantly worsened (p < 0.01). A regression analysis incorporating prospectively collected data identified variables that were predictive of changes in functional symptoms following surgery.

CONCLUSIONS

Flatulence was the only functional symptom to have worsened overall after surgery. Predictors of changes in functional symptoms may help clinicians when informing patients about gastrointestinal side effects following antireflux surgery.

Randomized clinical trial of laparoscopic Nissen fundoplication compared with proton-pump inhibitors for treatment of chronic gastro-oesophageal reflux

BACKGROUND

Both laparoscopic Nissen fundoplication (LNF) and proton-pump inhibitor (PPI) therapy are established in the treatment of gastro-oesophageal reflux disease (GORD). The aim of this study was to compare these two treatments in a randomized clinical trial.

METHODS

Between July 1997 and August 2001, 340 patients with a history of GORD for at least 6 months were investigated by endoscopy, 24-h pH monitoring and manometry. Of these, 217 were randomized, 109 to LNF and 108 to PPI therapy. The two groups were well matched for age, sex, weight and severity of reflux. Twenty-four-hour pH monitoring and manometry were performed 3 months after treatment, and quality of life was assessed in both groups using the Psychological General Well-being Index and the Gastrointestinal Symptom Rating Scale at 3 and 12 months after treatment.

RESULTS

At 3 months there was an improvement in lower oesophageal sphincter pressure from 6.3 to 17.2 mmHg in the LNF group but no change in the PPI group (8.1 and 7.9 mmHg before and after treatment respectively) (P < 0.001). The mean DeMeester acid exposure score improved from 42.7 to 8.6 (P < 0.001) in the LNF group and from 36.9 to 17.7 in the PPI group (P < 0.001). The mean gastrointestinal symptom and general well-being scores improved from 31.7 and 95.4 respectively before treatment to 37.0 and 106.2 at 12 months after LNF, compared with changes from 34.3 and 98.5 to 35.0 and 100.4 respectively in the PPI group. The differences in both of these scores were significant between the two groups at 12 months (P = 0.003).

CONCLUSION

LNF leads to significantly less acid exposure of the lower oesophagus at 3 months and significantly greater improvements in both gastrointestinal and general well-being after 12 months compared with PPI treatment.

Laparoscopic resection of gastric gastrointestinal stromal tumors

BACKGROUND

Gastrointestinal stromal tumors (GISTs) are neoplasms with low malignant potential. They occur most commonly in the stomach, where they are amenable to laparoscopic resection.

METHODS

A case note review of all patients undergoing laparoscopic resection of a presumed gastric GIST at the Norfolk and Norwich University Hospital, United Kingdom, was conducted.

RESULTS

Since September 1995, 30 patients have undergone this procedure. The patients had a mean age of 64.2 years (range, 31-87 years) and a mean weight of 74.1 kg (range, 44-104 kg). A presumptive diagnosis of GIST was made in all the cases based on the endoscopic and radiologic appearance of the lesion. Laparoscopic resection was completed successfully in 23 patients with a mean operating time of 73.8 min (range, 26-160 min). Seven procedures were converted to open surgery: three because the tumor was deemed too large for laparoscopic resection, two because the tumor could not be identified, one because of dense peritoneal adhesions, and one because of bleeding. The mean estimated blood loss was 196 ml (range, 0-1,000 ml), and the mean hospital stay was 5 days (ranges, 1-11 days). Pathologic analysis of the resected specimens showed 22 GISTs, 3 inflammatory fibroids, 2 submucosal lipomas, 1 submucosal varix, and 1 nest of heterotopic pancreatic tissue. D: uring a median follow-up period of 18 months (range, 2-101 months) there have been two cases of recurrence. In both cases, the tumor was catagorized as high risk for aggressive behavior after primary resection.

CONCLUSION

Stapled laparoscopic resection is a safe and effective treatment option for nonmetastatic primary gastric GIST.

Pericardial effusion and cardiac tamponade in pediatric stem cell transplant recipients

Pericardial effusion and cardiac tamponade is a rarely reported complication following stem cell transplant (SCT). The incidence among pediatric SCT recipients is not well defined. To assess the frequency of clinically significant pericardial effusions, we retrospectively examined clinically significant cardiac effusions at our center. Between January of 1993 and August 2004, clinically significant pericardial effusions were identified in nine of 205 patients (4.4%). The median age at the time of transplant was 9 years (range 0.6-18 years) and seven received an allogeneic transplant. All nine had normal cardiac function prior to transplant. The effusion developed at a median of 30 days (range 18-210 days). All allogeneic recipients had acute or clinically extensive graft-versus-host disease (GVHD) at the time the effusion was diagnosed. Seven patients (78%) required pericardiocentesis or surgical creation of a pericardial window. No patient died as a complication of the effusion or the therapeutic procedures. Clinically significant pericardial effusions are more common than previously reported in pediatric SCT recipients. Acute and chronic GVHD is an associated factor.

Stapled laparoscopic cystgastrostomy

BACKGROUND

The goal of this study was to assess the clinical outcome of patients undergoing laparoscopic stapled cystgastrostomy for pancreatic pseudocysts in contact with the posterior wall of the stomach.

METHODS

We performed a case note review of all patients who have undergone stapled laparoscopic cystgastrostomy in Norwich, UK. The cystgastrostomy was fashioned through an anterior gastrotomy using a vascular ETS stapling device in all cases.

RESULTS

Fifteen patients have undergone stapled laparoscopic cystgastrostomy. The procedure was completed successfully in 12 patients. Three procedures were converted to open surgery for technical reasons. There were no complications due to bleeding from the cystgastrostomy. Early complications included systemic sepsis (one), bleeding gastric ulcer (one) and pseudocyst recurrence due to partial closure of the cystgastrostomy (two). No late recurrences or other complications have been found at a median follow-up of 37 months.

CONCLUSION

Stapled laparoscopic cystgastrostomy is a safe and effective procedure for draining pancreatic pseudocysts in contact with the posterior wall of the stomach. The use of a hemostatic stapling device to fashion the cystgastrostomy may reduce the risk of catastrophic hemorrhage from the pseudocyst wall.

Endoscopic augmentation of the lower esophageal sphincter for the treatment of gastroesophageal reflux disease: multicenter study of the Gatekeeper Reflux Repair System

BACKGROUND AND STUDY AIMS

The safety and effectiveness of the Gatekeeper Reflux Repair System (Medtronic Europe, Tolochenaz, Switzerland) in the treatment of gastroesophageal reflux disease (GERD) was evaluated. This new, reversible treatment modality involves the endoscopic introduction of expandable polyacrylonitrile-based hydrogel prostheses into the esophageal submucosa to augment the lower esophageal sphincter (LES).

PATIENTS AND METHODS

For this study, data from two prospective, nonrandomized European multicenter trials were pooled. Sixty-nine GERD patients with heartburn and regurgitation and abnormal esophageal acid exposure (24-h pH < 4.0 for > 4 % of the total time) who had responded to proton-pump inhibitor (PPI) therapy were recruited, and 68 were treated with up to six prostheses placed at the gastroesophageal junction. Patients underwent esophageal manometry, endoscopy, 24-h pH-metry, and symptom scoring at intake and 1, 3, and 6 months after the procedure.

RESULTS

A total of 77 procedures were performed in 67 patients, and a total of 270 prostheses were placed (mean 4.3 per procedure). At 1 and 6 months, 80.4 % and 70.4 % of the prostheses were retained, respectively. At 6 months, 24-h pH-metry outcomes with pH < 4.0 for > 4.0 % of the time decreased from 9.1 % to 6.1 % (n = 45; P < 0.05). Median LES pressure increased significantly from 8.8 mmHg at baseline to 13.8 mmHg at 6 months (n = 42, P < 0.01). Median GERD heartburn-related quality-of-life scores improved significantly from 24.0 to 5.0 (n = 53, P < 0.01) in patients no longer receiving PPI therapy. Two serious adverse events (3.0 %) occurred. Both patients recovered uneventfully. Prostheses were endoscopically removed from one patient without any adverse events.

CONCLUSIONS

The Gatekeeper Reflux Repair System is a safe endoscopic treatment modality that significantly improves GERD symptoms and has objective effects on acid reflux.