Gastric half emptying time (T½ ) for 4-h gastric emptying scintigraphy simplifies reporting but reduces detection of gastroparesis

Gastric emptying scintigraphy: Comparison of imaging times for diagnosing rapid gastric emptying, a single center experience

This study aimed to evaluate the diagnostic utility of the 30- and 60-minute imaging time points for rapid gastric emptying (RGE) using gastric emptying scintigraphy. The primary objective was to determine whether the 30-minute time point, unique to the Miami Method, provides additional diagnostic value compared to the standard 60-minute time point recommended by the National Standard Protocol. A retrospective analysis was conducted on consecutive patients who underwent gastric emptying scintigraphy between 2015 and 2021. Patients were included if they completed imaging at both 30 and 60 minutes using a hybrid protocol incorporating the Miami Method and the National Standard Protocol. The McNemar's test was used to compare the frequency of RGE diagnosis at the 30- and 60-minute time points and Cohen's Kappa coefficient to assess the inter-time point agreement. Among the 38 patients diagnosed with RGE, 24 patients (63%) were diagnosed with RGE only at 30 minutes, 6 patients (16%) were diagnosed with RGE only at 60 minutes, and 8 patients (21%) were diagnosed with RGE at both 30 and 60 minutes. The McNemar's test showed a statistically significant difference (P = .0024) between the 30- and 60-minute time points, indicating that 30-minute imaging identifies a distinct group of patients who might not be diagnosed at 60 minutes. However, there was poor agreement between the 2 time points (Cohen's Kappa = -0.34), suggesting that the 30-minute time point may need further validation. The 30-minute imaging time point detected more cases of RGE compared to the 60-minute time point, suggesting that it may capture early rapid emptying events missed at 60 minutes. However, the lack of agreement between the time points raises concerns about overdiagnosis. These findings highlight the need for further research to validate the clinical utility of the 30-minute time point and determine its impact on patient management and outcomes.

Can an Abnormal Gastric Emptying Study Be Normal?

The American Neurogastroenterology and Motility Society and the Society of Nuclear Medicine and Molecular Imaging collaboratively wrote consensus statements to standardize gastric emptying scintigraphy. Despite this, centers are using nonstandard protocols. This study examined how these protocols contrast with standards. Methods: Consecutive charts were analyzed for meal, radionuclide dose, half-emptying time (T½) and its normal range, and documented retention and emptying. Impressions were compared with how emptying mapped on a graph based on standard 4-h values. Results: Thirty-four studies were identified. Ten of 14 abnormal studies were normal when plotted on the standard 4-h graph. Eight of 10 abnormal studies had normal 2- or 4-h retention. Normal T½ ranges varied significantly. Most altered the meal, and over 25% received a radionucleotide dose outside the recommended range. Conclusion: The upper bound of normal T½ falls within standard 4-h bounds, with many individuals given an erroneous impression. Though further optimization may be needed, adhering to standards is critical.

Symptoms from the Gastroparesis Cardinal Symptom Index and clinical factors associated with delayed gastric emptying in patients with suspected gastroparesis

BACKGROUND

The association between upper gastrointestinal symptoms and delayed gastric emptying (GE) shows conflicting results. This study aimed to assess whether the symptoms of the Gastroparesis Cardinal Symptom Index (GCSI) and/or the scores were associated with the result of GE tests and whether they could predict delayed GE.

METHODS

Patients referred for suspected gastroparesis (GP) were included in a prospective database. Demographical data, medical history, and symptoms of the GCSI score were collected for each patient. A GE scintigraphy was then performed with a 4-hour recording. Delayed GE was defined as a retention rate ≥ 10% at 4 h.

RESULTS

Among 243 patients included in this study, 110 patients (45%) had delayed GE. The mean age (49.9 vs. 41.3 years; p < 0.001) and weight loss (9.4 kg vs. 5.6 kg; p = 0.025) were significantly higher in patients with delayed GE. Patients with diabetes or a history of surgery had a higher prevalence of delayed GE (60% and 78%, respectively) than patients without comorbidity (17%; p < 0.001). The GCSI score was higher in patients with delayed GE (3.06 vs. 2.80; p = 0.045), but no threshold was clinically relevant to discriminate between patients with normal and delayed GE. Only vomiting severity was significantly higher in patients with delayed GE (2.19 vs. 1.57; p = 0.01).

CONCLUSION

GE testing should be considered when there are symptoms such as a higher weight loss, comorbidities (diabetes, and history of surgery associated with GP), and the presence of vomiting. Other symptoms and the GCSI score are not useful in predicting delayed GE.

Gastroparesis: time for a paradigm change

PURPOSE OF REVIEW

Gastroparesis (GP) is a syndrome defined by symptoms and delayed gastric emptying in the absence of mechanical obstruction. Typical symptoms include nausea, vomiting, abdominal pain, and early satiety. Only one medication is currently FDA-approved for the treatment of GP. This review highlights recent research findings pertaining to GP and provides evidence to support a change in the current GP diagnostic and treatment paradigm.

RECENT FINDINGS

An analysis of GP trials over the past four decades demonstrates the power of placebo and the need to perform longer studies with clearly defined patient populations. Two studies highlight the need to evaluate patients with suspected GP carefully and to perform gastric emptying studies properly. The misdiagnosis of GP symptoms is reviewed, preceded by a discussion of whether GP should be considered a disorder of gut-brain interaction. Finally, new data on therapies that target the pylorus are highlighted.

SUMMARY

Gastroparesis is frequently over-diagnosed and incorrectly diagnosed. Performing a proper gastric emptying study which adheres to standard protocol, and accurately interpreting the results in the context of the individual patient, are critical to making an accurate diagnosis of GP. The treatment paradigm needs to shift from simply aiming to accelerate gastric emptying to treating global symptoms of a chronic syndrome that may represent gut-brain dysfunction in many patients.

Ten controversies in gastroparesis and a look to the future

BACKGROUND

Gastroparesis is a complex, challenging gastrointestinal disorder presenting with upper gastrointestinal symptoms, especially nausea and vomiting, with significant impact on patients' quality of life. After ruling out mechanical obstruction, it is essential to identify delay in gastric emptying for definitive diagnosis. The most common causes are idiopathic (no identified etiology), diabetes mellitus, and postsurgical status. Management of gastroparesis focuses on dietary modifications and treatment directed to symptom relief. Unfortunately, approximately one-third of patients are refractory to pharmacological therapy, and the effectiveness of the few nonpharmacological options has been questioned.

PURPOSE

Extensive review of the literature identifies several uncertainties or controversies regarding the differential diagnosis based on the spectrum of symptoms, the lack of availability of reliable diagnostic test, and questions regarding effective therapeutic options. In this review, we discuss ten controversies regarding gastroparesis: clinical presentation, diagnosis, overlap syndromes, pathophysiology, etiology, as well as pharmacological and nonpharmacological therapeutic options. In addition, we briefly review studies exploring pathological, inflammatory, and molecular disturbances affecting the intrinsic neuromuscular elements that may be involved in the pathophysiology of gastroparesis and may constitute possible therapeutic targets in the future. Finally, we tabulate future research opportunities to resolve these controversies in the management of patients with gastroparesis.

Prevalence of delayed gastric emptying in patients with gastroparesis-like symptoms

BACKGROUND

The European consensus defined gastroparesis as a condition characterised by delayed gastric emptying (GE) in the absence of mechanical obstruction, with a symptom pattern of predominant nausea and/or vomiting and overlapping postprandial distress syndrome (PDS). The distinction between patients with gastroparesis and those with functional dyspepsia (FD), another gastrointestinal condition characterised by predominant PDS or epigastric pain syndrome symptoms, is ongoing.

AIM

To investigate the extent that symptom patterns may differentiate gastroparesis from FD.

METHODS

This retrospective study included 637 patients from Leuven University Hospital in 2006-2021 who had upper gastrointestinal symptoms, underwent a GE test, and completed the Dyspepsia Symptom Severity (DSS) questionnaire. Patients were identified as with gastroparesis-like symptoms (GPLS; i.e., moderate to severe nausea with moderate to severe PDS) or FD symptoms (not fitting GPLS). We excluded patients aged <18 years, and those with diabetes, organic gastrointestinal disease or a history of abdominal surgeries. Demographic and clinical variables were compared.

RESULTS

Among 545 patients, 238 reported GPLS and 307 reported FD symptoms. Those with GPLS had a significantly higher prevalence of delayed GE (half emptying time (T1/2) ≥109 min) and lower body mass index than those with FD (33.2% vs 17.6%, p < 0.01; 19.9 vs 21.2, p < 0.01, respectively). Among GPLS patients, those with delayed GE had higher DSS than those without (13.0 vs 12.0, p < 0.01).

CONCLUSIONS

In tertiary care patients who reported gastroparesis or FD symptoms, the presence of delayed GE was associated with GPLS. In patients with GPLS, delayed GE was associated with higher symptom severity.

A Comparative Assessment of the Diagnosis of Swallowing Impairment and Gastroesophageal Reflux in Canines and Humans

Swallowing impairment is a highly prevalent and clinically significant problem affecting people and dogs. There are myriad causes of swallowing impairment of which gastroesophageal reflux is the most common in both species. Similarities in anatomy and physiology between humans and canines results in analogous swallowing disorders including cricopharyngeus muscle achalasia, esophageal achalasia, hiatal herniation, and gastroesophageal reflux with secondary esophagitis and esophageal dysmotility. Accordingly, the diagnostic approach to human and canine patients with swallowing impairment is similar. Diagnostic procedures such as swallowing fluoroscopy, high-resolution manometry, pH/impedance monitoring, and endolumenal functional luminal imaging probe can be performed in both species; however, nasofacial conformation, increased esophageal length, and the difficulty of completing several of these procedures in awake dogs are inherent challenges that need to be considered. Human patients can convey their symptoms and respond to verbal cues, whereas veterinarians must rely on clinical histories narrated by pet owners followed by comprehensive physical examination and observation of the animal eating different food consistencies and drinking water. Dogs may also be unwilling to drink or eat in the hospital setting and may be resistant to physical restraint during diagnostic procedures. Despite the species differences and diagnostic challenges, dogs are a natural animal model for many oropharyngeal and esophageal disorders affecting people, which presents a tremendous opportunity for shared learnings. This manuscript reviews the comparative aspects of esophageal anatomy and physiology between humans and canines, summarizes the diagnostic assessment of swallowing impairment in both species, and discusses future considerations for collaborative medicine and translational research.