Doctors at the All India Institute of Medical Sciences (AIIMS) in New Delhi have identified two high-risk anatomical zones that could make complex cancer surgery in women safer by reducing bleeding and preventing injury to vital organs. The breakthrough in cancer surgery technique was reported by PTI on October 18.
Dr M D Ray, professor in the Department of Surgical Oncology at Dr BRA-IRCH, AIIMS Delhi, along with his team, identified an area below the uterine vessels as the “Red Alert Zone” or “Ray’s Zone”, where the ureter, urinary bladder, pelvic nerves and important blood vessels lie in close proximity. The concept emerged from a study of 255 radical or modified radical hysterectomies performed for cervical, endometrial and ovarian cancers.
Inside Ray’s Zone: the pelvic warning area
Ray’s Zone is an anatomical warning area. After analysing the anatomy and causes of operative bleeding and injury in the first set of cases, the surgical approach was modified in the later 105 cases. The cancer surgery technique emphasises meticulous anatomical visualisation, magnification when required, individual vessel ligation and avoidance of excessive cautery near the pelvic ureter.
Researchers said careful dissection in Ray’s Zone could help reduce blood loss and minimise ureteric, bladder and pelvic nerve injuries, thereby improving postoperative function and quality of life for women undergoing cancer surgery for gynaecological cancers.
The second zone: Ray’s Hepatocaval Triangle
Dr Ray has also described another surgically important area, termed “Ray’s Hepatocaval Triangle”, relevant during liver mobilisation and dissection near the inferior vena cava and major hepatic venous structures. The hepatocaval region is considered technically demanding because uncontrolled manipulation can result in major vascular injury and severe bleeding.
According to the surgical concept, defining this anatomical triangle provides surgeons with a clearer operative reference while handling the liver near major vessels. A separate AIIMS study, published in the Journal of the Egyptian National Cancer Institute, analysed 205 patients with ovarian cancer who underwent extensive surgery involving mobilisation of the liver, underlining how critical these regions are in advanced cancer surgery.
Cancer surgery principle: map danger before entering
Both anatomical concepts rest on a common principle: identifying a potentially hazardous surgical area before entering it and performing controlled, anatomy-guided dissection. The researchers said such anatomical mapping could improve surgical precision and help preserve vital structures during major oncological procedures.
In simple terms, Ray’s Zone in the pelvis and Ray’s Hepatocaval Triangle near the liver act as anatomical warning zones, reminding surgeons where maximum precision and caution are required during cancer surgery. The concepts are now expected to be incorporated into surgical training, giving younger oncologists a named reference for zones their seniors learned to respect through experience.
Cancer surgery outcomes: what patients gain
For patients, the payoff is tangible. Less blood loss means fewer transfusions and shorter recovery times; fewer injuries to the ureter, bladder and pelvic nerves means better postoperative function and quality of life. As cancer surgery grows more aggressive in pursuit of complete tumour removal, tools like Ray’s Zone that make the procedures safer are as valuable as the techniques that make them possible.
Published research backs the approach
The AIIMS team’s work builds on published research into complex abdominal oncology. A related study by Dr Ray, published in the Journal of the Egyptian National Cancer Institute, analysed 205 patients with ovarian cancer who underwent extensive surgery involving mobilisation of the liver at AIIMS between January 2014 and December 2025. It highlighted the need for surgeons to carefully expose areas behind and around the liver, where cancer deposits can sometimes remain hidden.
In that study, complete or near-complete removal of visible cancer was achieved in 194 patients, or 94.6 per cent, with complete removal of all visible disease in 178 patients. The researchers also recorded injuries to the right hepatic vein, a major vein carrying blood from the liver, in nine patients, or 4.4 per cent, a reminder of how dangerous the hepatocaval region can be. Concepts like Ray’s Zone and the hepatocaval triangle give surgeons a named, teachable reference for exactly those high-stakes areas, turning hard-won operative experience into guidance that can be passed on.