Laparoscopic (L-) versus Robotic Assisted (RA-) Roux-en-y Gastric Bypass (RYGB): effects on lung function, respiratory muscle strength, and physical activity after six months

Obesity is a chronic and multifactorial disease associated with systemic changes and pulmonary impairment. Roux-en-Y gastric bypass (RYGB) is effective in treating severe obesity and has been associated with improvements in pulmonary function; however, evidence comparing the effects of laparoscopic (L) and robotic-assisted (RA) RYGB on respiratory outcomes remains limited. To compare the effects of L- and RA- RYGB on lung function, respiratory muscle strength and physical activity level, at baseline and six months postoperatively. Prospective, non-randomized study conducted at a private bariatric surgery center in Brazil, including patients of both sexes, aged 18-65 years with body mass index (BMI) 40.0-49.9 kg/m² undergoing Roux-en-Y gastric bypass. Patients with a history of smoking or pre-existing pulmonary disease were excluded. Patients were divided into L- and RA- groups and evaluated at baseline and six months after surgery with spirometry (forced vital capacity [FVC], forced expiratory volume in one second [FEV₁], and FEV₁/FVC ratio), manovacuometry (maximal inspiratory pressure [MIP] and maximal expiratory pressure [MEP]), and physical activity level (International Physical Activity Questionnaire-Short Form [IPAQ-SF]), following ATS/ERS standards. Statistical analyses included chi-square, Fisher's exact, Student's t, Mann-Whitney U, and mixed-effects models (p < 0.05). A total of 98 patients were included (49 L-, 49 RA-), with 84 completing the six-month follow-up. Among those who completed follow-up, most participants were women (75.0%), with a mean age of 37.3 years. Significant improvements in pulmonary function were observed over time following surgery. Although a reduction in maximal expiratory pressure was observed in the laparoscopic group in within-group analyses, mixed-effects models showed no significant differences between surgical approaches regarding respiratory muscle strength, pulmonary function, physical activity level, or longitudinal changes over time. Laparoscopic and robotic-assisted Roux-en-Y gastric bypass were associated with improved pulmonary function six months after surgery, with no significant differences between surgical approaches in respiratory outcomes or physical activity level.