In Jain tradition, for operation (surgery) success, devotees commonly recite:

• Namokar Mantra
• Complete Bhaktamar Stotra
• Especially the 1st shloka of Bhaktamar with श्रद्धा and calm mind

Bhaktamar is recited for peace, protection, and removal of fear, but in Jain Dharma it should be understood as a prayer with devotion, not as a guarantee. The most important thing is faith, purity, and right conduct.

A simple practice before operation:

1. Take the name of Arihant / Parmatma
2. Recite Namokar Mantra 9 or 27 times
3. Recite Bhaktamar Stotra or at least the first shloka
4. Pray with a calm and pure heart

If you want, I can give you the first Bhaktamar shloka with arth in a simple way.