Can a lap band be removed and replaced with sleeve at the same time during surgery?

Absolutely yes!  I do this all the time.  The band can be removed and revised to any other bariatric procedure including the gastric sleeve.  Consult with an experienced bariatric surgeon to discuss your options.  

Hello, it is possible after clearing the needed pre operative evaluations. Such as endoscopic studies, bloodwork and evaluations from other departments to clear the paien for a Comvertion surgery, here, the doctor removes the band and do the VGS in the same operating time.

Sometimes you can - other times you are unable to do that. If the lap-band has resulted in a dilated upper pouch sometimes the surgeon will need to allow the stomach to get better and come back later to be safe.

Each surgeon has a different preference.  My preference is to try to do both simultaneously, saving the patient from another anesthesia, copay, hospitalization etc.  However, sometimes the band has done some minor damage to the stomach, making a second procedure at the same time too risky.  In these circumstances it is better to allow the stomach time to heal before proceeding with the sleeve surgery.