 You are a biomedical researcher, and please answer the following question based on the context. 
In your answer, please first state the final answer in YES/NO/MAYBE, then include a brief explanation.

### Question: Is preoperative manometry necessary for evaluating reflux symptoms in sleeve gastrectomy patients?

### Context: 1: The effect of laparoscopic sleeve gastrectomy (LSG) in gastroesophageal reflux disease (GERD) is controversial. However, it has been reported that up to 22% of patients presented with symptomatic GERD after LSG. The aim of our study was to evaluate the necessity of preoperative manometric testing in LSG patients.
2: We prospectively collected the data on LSG candidate patients who underwent preoperative manometric testing. The normal range for the lower esophageal sphincter (LES) pressure is 10.0-45.0 mmHg. Each patient was interviewed for the GERD score questionnaire (scaled severity and frequency of heartburn, regurgitation, epigastric pain, epigastric fullness, dysphagia and cough) at the time of the manometric study.
3: Forty-nine patients were studied. The mean preoperative LES pressure was 13.2±7.7 mmHg (range, 1.0-34.4). Eleven patients responded that they had 1 or more moderate to severe GERD symptoms>2-4 times a week, of which 9 had competent LES pressures. Thirteen (26.5%) patients had decreased LES pressures, and only 3 (23.1%) of these reported moderate to severe symptoms of GERD. In 26 LSG patients with postoperative results, the mean preoperative LES pressure was 14.8±8.0 mmHg (range, 3.5-34.4), and the mean GERD score did not show a significant difference at 9 months after LSG. Twenty-two had normal LES pressures, and 16 (72.8%) of these patients reported reflux symptoms preoperatively. Only 2 (12.5%) of these symptomatic patients reported a higher GERD score postoperatively, but the difference was not significant. Of the 4 patients who had low LES pressures, only 1 patient complained of mild GERD symptoms preoperatively. However, this patient and another without preoperative symptoms developed severe GERD symptoms postoperatively.


###Response: Manometric study may be necessary in LSG patients to accurately evaluate GERD and the LES pressure.
 