The most riskiest surgery is a Craniectomy surgery.
The Craniectomy surgery involves removing a fraction of the skull to relieve pressure on the brain and is one of the highest risks surgeries.
Regular brain surgery is also the next highest risk surgeries there is.
And then Open Heart Surgery is also on the list of being the highest and most riskiest surgeries.
Other high risk surgeries include.
Thoracic aortic dissection repair.
Oesophagectomy.
Spinal osteomyelitis surgery.
Bladder cystectomy.
Gastric bypass.
Separation of conjoined twins.
Some other high risk surgeries include.
Small bowel resection (removal of all or part of a small bowel).
Gallbladder removal.
Peptic ulcer surgery to repair ulcers in the stomach or first part of small intestine.
Removal of peritoneal (abdominal) adhesions (scar tissue).
Major surgery is any invasive operative procedure in which a more extensive resection is performed, e.g. a body cavity is entered, organs are removed, or normal anatomy is altered.
In general, if a mesenchymal barrier is opened (pleural cavity, peritoneum, meninges), the surgery is considered major.
While any surgical procedure has risks, bariatric surgery has been found to be one of the safest surgeries to undergo.
It is considered as safe or more safe when compared to other elective surgeries.