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Nicholas Stylopoulos

Publications and source records attributed to Nicholas Stylopoulos.

7 recordsLinked to original sources
PubMed2025

Baseline metabolomic profile as potential biomarker for weight change after Roux-en-Y gastric bypass (RYGB) surgery.

Metabolic and bariatric surgery (MBS) is the most effective intervention for sustained weight loss and cardiometabolic improvement in individuals with severe obesity. However, long-term outcomes vary, with many patients experiencing weight regain. The biological determinants of this variability remain incompletely understood. Given the integrative nature of the metabolome-capturing interactions among host genetics, diet, microbiota, and environmental exposures-we hypothesized that baseline circulating metabolites could stratify individuals into distinct long-term weight trajectory groups. We profiled untargeted fasting plasma metabolites in a nested case-control study within the Longitudinal Assessment of Bariatric Surgery (LABS-2) cohort. From these metabolites, a 13-metabolite risk score (MetRS) predictive of weight regain five years after Roux-en-Y gastric bypass was derived. The MetRS, which captures pathways including fatty acid oxidation, bile acid conjugation, and microbial-host co-metabolism, outperformed clinical variables in predicting long-term weight outcomes. Its performance was evaluated in two independent cohorts, including one assessed a median of seven years post-surgery. Genomic analyses identified common variants in loci including AGXT2 and SLC7A5 associated with key MetRS metabolites, suggesting a heritable component to the observed metabolic signature. Together, these findings lay the groundwork for a clinically actionable framework to identify individuals at risk for weight recidivism and support the integration of metabolic profiling into preoperative assessment for personalized obesity care.

Journal Article↗
PubMed2005

The history of hiatal hernia surgery: from Bowditch to laparoscopy.

OBJECTIVE: This review addresses the historical evolution of hiatal hernia (HH) repair and reports in a chronological fashion the major milestones in HH surgery before the laparoscopic era. METHODS: The medical literature and the collections of the History of Medicine Division of the National Library of Medicine were searched. Secondary references from all sources were studied. The senior author's experience and personal communications are also reported. RESULTS: The first report of HH was published in 1853 by Bowditch. Rokitansky in 1855 demonstrated that esophagitis was due to gastroesophageal reflux, and Hirsch in 1900 diagnosed an HH using x-rays. Eppinger diagnosed an HH in a live patient, and Friedenwald and Feldman related the symptoms to the presence of an HH. In 1926, Akerlund proposed the term hiatus hernia and classified HH into the 3 types that we use today. The first elective surgical repair was reported in 1919 by Soresi. The physiologic link between HH and gastroesophageal reflux was made at the second half of the 20 century by Allison and Barrett. In the midst of a physiologic revolution, Nissen and Belsey developed their famous operations. In 1957, Collis published his innovative operation. Thal described his technique in 1965, and in 1967, Hill published his procedure. Many modifications of these procedures were published by Pearson and Henderson, Orringer and Sloan, Rossetti, Dor, and Toupet. Donahue and Demeester significantly improved Nissen's operation, and they were the first to truly understand its physiologic mechanism. CONCLUSION: Hiatal hernia surgery has evolved from anatomic repair to physiological restoration.

Fundoplication↗
PubMed2003

Robotics and ergonomics.

Industrial robotics have proven the benefit of using an untiring machine to perform precise repetitive tasks in uncomfortable or dangerous for humans environments. Highly skilled surgeons are trained to operate and adapt to difficult conditions. They are even capable of developing intelligent mechanisms to exploit a variety of tactile, visual, and other cues. The robotic systems, however, can enhance the surgeon's capability to perform a wide variety of tasks. They cannot replace the surgeon's problem-solving ability. Instead, they will redefine his role. They will significantly enhance the surgeon's skills and dexterity by providing their complementary capabilities and an ergonomically efficient and more user-friendly working environment.

Cost-Benefit Analysis↗
PubMed2002

Paraesophageal hernias: operation or observation?

OBJECTIVE: To examine the hypothesis that elective laparoscopic repair should be routinely performed on patients with asymptomatic or minimally symptomatic paraesophageal hernias. SUMMARY BACKGROUND DATA: The management of asymptomatic paraesophageal hernias is a controversial issue. Most surgeons believe that all paraesophageal hernias should be corrected electively on diagnosis, irrespective of symptoms, to prevent the development of complications and avoid the risk of emergency surgery. METHODS: A Markov Monte Carlo decision analytic model was developed to track a hypothetical cohort of patients with asymptomatic or minimally symptomatic paraesophageal hernia and reflect the possible clinical outcomes associated with two treatment strategies: elective laparoscopic paraesophageal hernia repair (ELHR) or watchful waiting (WW). The input variables for ELHR were estimated from a pooled analysis of 20 published studies, while those for WW and emergency surgery were derived from the 1997 HCUP-NIS database and surgical literature published from 1964 to 2000. Outcomes for the two strategies were expressed in quality-adjusted life-years (QALYs). RESULTS: Analysis of the HCUP-NIS database showed that published studies overestimate the mortality of emergency surgery (17% vs. 5.4%). The mortality rate of ELHR was 1.4%. The annual probability of developing acute symptoms requiring emergency surgery with the WW strategy was 1.1%. For patients 65 years of age, ELHR resulted in reduction of 0.13 QALYs (10.78 vs. 10.65) compared with WW. The model predicted that WW was the optimal treatment strategy in 83% of patients and ELHR in the remaining 17%. The model was sensitive only to alterations of the mortality rates of ELHR and emergency surgery. CONCLUSIONS: If ELHR is routinely recommended, it would be more beneficial than WW in fewer than one of five patients. WW is a reasonable alternative for the initial management of patients with asymptomatic or minimally symptomatic paraesophageal hernias, and even if an emergency operation is required, the burden of the procedure is not as severe as was thought in the past.

Age Factors↗
PubMedDate not supplied

Development of achalasia secondary to laparoscopic Nissen fundoplication.

Dysphagia after laparoscopic Nissen fundoplication (LNF) is commonly attributed to edema and/or improperly constructed wraps, and in some instances the cause can be difficult to identify. We report, for the first time, the development of secondary achalasia after LNF as a cause of late-onset postoperative dysphagia. A total of 250 consecutive patients undergoing LNF were analyzed for the development of postoperative dysphagia at a university hospital. Patients were considered to have secondary achalasia if they met the following four criteria: (1) preoperative manometry demonstrating normal peristalsis and normal lower esophageal sphincter (LES) relaxation; (2) lack of esophageal peristalsis on postoperative manometry or fluoroscopy with or without incomplete LES relaxation; (3) no mucosal lesions seen on endoscopy; and (4) dysphagia refractory to dilatation. The following three groups of patients were identified: patients who developed secondary achalasia (group A, n = 7); patients with persistent dysphagia requiring and responding to postoperative dilatation (group B, n = 12 patients); and patients whose postoperative recovery was not complicated by dysphagia (group C, n = 231). The groups were comparable in terms of all preoperative variables except for age. Patients in group A were older than those in group B (57 years [range 27 to 66 years] vs. 36.5 years [range 27 to 63 years], P = 0.028) but were not significantly older than patients in group C (45 years [range 20 to 84 years], P = 0.42). The onset of severe dysphagia was later in group A than in group B (135 days [range 15 to 300 days] vs. 20 days [range 9 to 70 days], P = 0.002). The median weight loss in group A was also significantly greater than in Group B (15 pounds [range 11 to 44 pounds] vs. 4 pounds [range 0 to 15 pounds], P = 0.0007). Two patients in group A who underwent reoperation failed to improve. Botulinum toxin injections were tried in two patients and Heller myotomy in one with good results. Nine patients in group B improved promptly after one dilatation, and three improved after two dilatations. Secondary achalasia should be considered as one of the causes of persistent dysphagia after an apparently successful antireflux operation. Secondary achalasia tends to occur in older patients and is characterized by a delayed onset of symptoms. Imaging studies are a reliable means of excluding mechanical obstruction as a cause of secondary achalasia, and a negative result should raise the suspicion of secondary achalasia. Esophageal motility studies are necessary to confirm the diagnosis. Failure to consider the diagnosis of secondary achalasia can lead to multiple fruitless attempts at dilatation or even inappropriate reoperations.

Adult↗