Esomeprazole

Omental fat biopsies were collected into ice-cold PBS, then transferred to ice cold Krebs solution (NaCl 120 mM, KCl 5 mM, MgSO₄ 1.2 mM, KH₂PO₄ 1.2 mM, NaHCO₃ 25 mM, D-glucose 11.1 mM, CaCl₂ 2.5 mM) and kept on ice or at 4 °C until dissection. Arteries of approximately 2 mm length were isolated from surrounding fat and connective tissue. Dissected arteries were mounted on wire myograph chambers (620 M Wire Myograph, Danish Myo Technology, DMT, Hinnerup, Denmark) with 40 µm diameter tungsten wire (DMT). The chamber baths were filled with Krebs solution and bubbled continuously with carbogen (95% O₂, 5% CO₂). PowerLab hardware accompanied by Labchart software (ADInstruments, NSW, Australia) were used to collect and convert force measurements. The chambers with mounted vessels were incubated at 37 °C for 30 min. The vessels were normalised to 100 mmHg (13.3 kPa) pressure using the DMT normalisation module on LabChart with IC1/IC100 = 1, then allowed to equilibrate for 20 min.
Following equilibration, vessel viability was assessed. The vessels were first briefly constricted with high potassium physiological salt solution (50 mM KPSS: NaCl 75 mM, KCl 50 mM, MgSO₄ 1.2 mM, KH₂PO₄ 1.0 mM, NaHCO₃ 25 mM, D-glucose 11.1 mM, CaCl₂ 2.5 mM) to assess smooth muscle viability. Endothelial function was confirmed by pre-constricting the vessel with the thromboxane agonist 9,11-dideoxy-9α,11α-methanoepoxy prostaglandin F2α (U46619; Sapphire Bioscience, Redfern, NSW, Australia) to 50–70% of maximal response to KPSS, followed by the addition of endothelium-dependent vasodilator bradykinin (Sapphire Bioscience). At least 80% relaxation was required to consider the endothelium intact. After 20 min of rest, the vessels were constricted with U46619 (to 50–70% of maximal response to KPSS), then treated with increasing doses (0.1–100 µM) of esomeprazole magnesium hydrate (MH) or esomeprazole magnesium trihydrate (MTH) or control (vehicle).

The TC and PPI period was calculated from the index date until the conclusion of the study.
Patients were divided into the following four groups: TC-/PPI-, TC + /PPI-, TC-/PPI + , and TC + /PPI + .

(1) The TC-/PPI- group consisted of patients who were neither on TC nor PPI therapy (control group).

(2) The TC + /PPI- group consisted of patients whose period of TC (doxycycline or minocycline) and EGFR-TKI therapy overlapped by at least 20% but were not on PPIs.

(3) The TC-/PPI + group consisted of patients whose period of PPI (esomeprazole, pantoprazole, rabeprazole, or lansoprazole) and EGFR-TKI therapy overlapped by at least 20% but were not on TCs.

(4) The TC + /PPI + group consisted of patients taking TCs and PPIs concomitantly with EGFR-TKI therapy, and both therapeutic regimens overlapped by at least 20%.

A standardized postoperative protocol tailored to bariatric patients was used [10 (link),12 (link)]. The severity of postoperative complications was graded according to the Clavien-Dindo classification [13 (link)]. A routine follow-up with blood test analysis and physical examination was performed according to the guidelines of the Italian Society of Bariatric Surgery (SICOB) [https://www.sicob.org/00_materiali/linee_guida_2016.pdf, (accessed on 20 December 2022)]. At discharge, patients were advised to follow a strict diet consisting of three progressive phases (clear liquid, semi-solid, and solid), each lasting at least 2–3 weeks and supplemented with proteins, vitamins, and minerals (Table 1). Protein supplementation was indicated because clinical practice guidelines for perioperative support of bariatric patients by the Bariatric Surgery Societies (SICOB, IFSO) recommend a daily protein intake of at least 60 up to 1.5 g/kg for an ideal body weight. All patients received directions to buy a particular vitamin and mineral bariatric supplement (FitForMe WLS Maximum^®, Fit for Me, DA Rotterdam, The Netherlands) that is tailor-made for bariatric patients who have undergone hypoabsorptive procedures (see Table 2 for composition). Patients purchased the product at their own expense.
Vitamin supplementation during the study period was highly recommended. All patients received enoxaparin (4000 UI/0.4 mL) for 4 weeks and a proton pump inhibitor (PPI) (esomeprazole, 40 mg daily) for at least 6 months as part of the standard postoperative protocol.