Robotic Surgery Gave Her Life Back — Without One.

Nobody is ever ready for it. Not at 40.

Priya — a teacher from Bangalore, a mother, someone whose days were filled with the noise of a full life — noticed something had been off for a few months. Blood. Discomfort. A feeling that wouldn’t settle. She kept putting it down to stress, to diet, to the kind of minor complaints you tell yourself will sort themselves out.

But they didn’t sort themselves out.

A colonoscopy gave her the answer she had been dreading: low rectal cancer. The tumour was sitting just 3.5 centimetres from the opening of her back passage — a distance that, in most hospitals, only leads to one conclusion. Every surgeon she saw said the same thing, more or less politely:

“You will need an abdominoperineal resection. The rectum and the anus have to come out. You will have a permanent colostomy bag for the rest of your life.”

— The consensus from multiple surgeons before Dr. Nayak’s opinion

A bag on her abdomen. Forever. She was 40 years old.

She sat with that for a few days. And then — the way people do when they are not ready to accept an answer — she looked for another one. A colleague mentioned a surgeon in Bangalore who was doing something different. Something robotic. Something that, in the right patient, might actually save the sphincter.

She found Dr. Sandeep Nayak.

Before any surgery, there is a thorough assessment. Dr. Nayak reviewed everything — the scans, the reports, the chemo-radiotherapy history, the clinical examination. Here is the complete picture of what he found:

ISR sounds clean on paper. The reality of doing it, especially in a post-radiation pelvis on a thin patient, is anything but. There were at least four factors that made this operation technically demanding — and that would have sent most surgeons straight to a permanent stoma.

At 3.5 to 4 centimetres from the anal opening, the tumour sat in what colorectal surgeons refer to informally as the ‘problem zone’ — too low for a standard low anterior resection, but not so invasive that the external sphincter was gone. That narrow eligibility window is easy to misread. Surgeons who are not specialists in sphincter-preserving surgery often call it inoperable without a bag, simply because they are not trained to work in that space.

Priya had completed her chemo-radiotherapy six weeks before surgery — the standard and correct approach. But radiation does something to tissue that every pelvic surgeon dreads: it triggers fibrosis. The normal tissue planes that guide a surgeon — the natural spaces between organs that should peel apart with minimal force — get filled with dense, sticky scar tissue. Structures that should be easy to separate become glued together.

In Priya’s case, the adhesions between the rectum and the vaginal wall were particularly severe. That area became one of the most painstaking parts of the entire operation.

Being a thin patient actually works against the surgeon in pelvic operations. The mesentery is thin, the tissues are unforgiving, and there is very little ‘buffer’ between the scalpel and the vital structures nearby. Priya also had internal haemorrhoids — vascular structures that bleed readily and make the perineal phase of the operation messier and more demanding.

The pelvic autonomic nerves that run through this region control bladder function and sexual function. They are invisible to the naked eye in many parts of the pelvis, identifiable only by their position relative to key anatomical landmarks. Damage them and the patient wakes up with a new set of problems — incontinence, sexual dysfunction — on top of the cancer. The robotic camera, magnified 10 to 15 times in 3D, is not a luxury in this operation. It is a necessity.

Dr. Nayak spent time with Priya’s scans, her examination findings, and her story. The MRI was clear: the internal sphincter was involved, but the external sphincter was free. On physical examination, the tumour was mobile. The upper end was palpable. Crucially, she had responded well to chemo-radiotherapy — the tumour had shrunk.

In experienced hands, with the right technology, this was an ISR case. 

“When I examined her, the sphincters were clinically free and MRI confirmed it. She was young, fit, and had responded well to chemo-RT. There was no reason she should spend the rest of her life with a permanent bag. ISR is technically demanding — but in the right patient, it is the right thing to do.”

— Dr. Sandeep Nayak, Surgical Oncologist, MACS Clinic, Bangalore

Intersphincteric Resection works by exploiting a narrow anatomical space that most surgeons never enter: the plane between the internal and external anal sphincter. The internal sphincter — which the tumour involves — is removed along with the rectum. The external sphincter, which does the real work of continence, is left completely intact. The healthy colon is then brought down and joined directly to the anal canal.

The result is complete cancer clearance, with preserved bowel function. No bag.

What follows is a plain-language account of the actual surgery, based on Dr. Nayak’s live surgical teaching recorded during the procedure. It is told in the order it happened.

Step 1 — Setting Up: The Robot Advantage

Dr. Nayak used the da Vinci Xi — the most advanced generation of the da Vinci robotic surgical system. A key advantage of the Xi over older models is that the entire arm boom can rotate. This matters enormously for a surgery that has to cover both the upper abdomen (to mobilise the colon) and the deep pelvis (to remove the rectum and perform the intersphincteric dissection) — all in a single position without moving the robot.

Ports were placed along a precise line connecting the mid-clavicular point to the anterior superior iliac spine — a configuration that gives complete access from the splenic flexure to the pelvic floor. This straight-line port placement is specific to the Xi system, and it is one of the reasons single-docking is possible for a complex operation like this.

Step 2 — Identify, Then Protect

Before anything is cut, every vital structure in the surgical field has to be found and clearly identified. In the pelvis, a moment of inattention can damage structures that cannot be repaired. Dr. Nayak worked methodically through the anatomy:

• Left and right pelvic autonomic nerves — identified at the root of the inferior mesenteric artery and kept in view throughout the entire dissection
• Left ureter — traced from where it crosses the iliac vessels, followed deep into the pelvis to confirm its position at every stage
• Gonadal (ovarian) vessels — separated from the dissection plane and protected
• Gerota’s fascia — the covering layer over the left kidney, kept intact

In Priya’s case, the radiation fibrosis meant these structures were harder than usual to see and to protect. Nerves that normally sit clearly away from the surgical field were embedded in scar tissue. The ureter needed continuous checking as the dissection progressed.

Step 3 — Dividing the Blood Supply (High Ligation)

The inferior mesenteric artery — the main blood supply to the section of colon being removed — was divided close to its root on the aorta. This is called ‘high ligation,’ and it serves two purposes. First, it frees up enough length of healthy colon to bring down for the eventual join with the anal canal. Second, it ensures that all the lymph nodes around the artery — which may contain cancer cells — are removed with the specimen.

The inferior mesenteric vein was separately divided high up near the pancreas. The higher the vein is divided, the more length of colon is gained. Two clips were placed on the patient side, one on the specimen side — the specimen clip helps the pathologist identify the root of the vessel when examining the tissue after the operation.

Step 4 — Total Mesorectal Excision (TME): The Most Important Step

Total Mesorectal Excision — TME — is the cornerstone of rectal cancer surgery. It means removing the rectum together with its entire surrounding envelope of fatty tissue (the mesorectum), completely intact. Inside that envelope are all the lymph nodes and blood vessels through which rectal cancer tends to spread locally. A breached or incomplete TME dramatically increases the risk of the cancer coming back.

The dissection has to stay in the ‘Holy Plane’ — the precise space between the outer layer of the mesorectum and the surrounding pelvic structures. In this plane, the tissue is loose and relatively bloodless. Stray into the wrong layer and you are either inside the mesorectum (compromising the cancer clearance) or cutting into pre-sacral vessels that can bleed catastrophically.

Priya’s radiation fibrosis had collapsed parts of this plane. Where it should have opened with gentle pressure, it required careful, unhurried sharp dissection to re-establish the correct layer. The posterior dissection (behind the rectum) was completed first, then the lateral sides, and finally the anterior — the most difficult part in this case, where the rectum was densely adherent to the vaginal wall.

Step 5 — Splenic Flexure Mobilisation: Making Room

For the final join to be tension-free, the colon has to reach all the way down to the anal canal without being pulled tight. That means the entire left colon — including the curve near the spleen at the top of the abdomen — has to be freed from its attachments.

In India, many patients have longer sigmoid colons, which can complicate this mobilisation. In Priya’s case, the mesocolon was short, making a thorough splenic flexure mobilisation non-negotiable. The transverse colon was separated from the pancreas, the mesocolon was freed from the retroperitoneum, and the entire left colon was brought down into the field.

Step 6 — The Intersphincteric Dissection: The Reason She Kept Her Bowel

This is the defining step. This is what makes ISR different from every other operation for low rectal cancer.

Working from the abdominal side, Dr. Nayak entered the narrow plane between the internal and external anal sphincter and dissected circumferentially — going all the way around the rectum, all the way down to just one centimetre above the anal verge. The table-side assistant confirmed the depth by placing a finger in the anal canal from outside. One centimetre. Enough margin. The cancer would be out.

The puborectalis sling — the most important muscle for continence — was clearly identified and left completely untouched. The longitudinal muscle fibres of the rectum were cut carefully, one layer at a time. Haemorrhoidal vessels were controlled with minimal energy use to protect the surrounding muscle tissue.

The external sphincter was never threatened. Every millimetre of it was preserved.

Step 7 — ICG Firefly: Making Sure the Join Will Hold

Before the specimen was removed, Dr. Nayak used ICG fluorescence imaging — the ‘Firefly’ mode on the da Vinci Xi — to check the blood supply to the segment of colon that would form the join.

ICG (Indocyanine Green) is a dye injected into the bloodstream. Under infrared light, it glows bright green wherever blood is flowing well. A poor blood supply at the anastomosis — the join between the colon and the anal canal — is the most common reason the join fails (called anastomotic leak). ICG takes the guesswork out of it. Dr. Nayak marked his intended cut line based on the ICG signal, ensuring the join was placed in tissue with excellent circulation.

Step 8 — Perineal Phase and Specimen Removal

The final phase moved to the perineal approach — working from the anal side. Using a mini-Buckler retractor to open the anal canal, Dr. Nayak injected an adrenaline solution to reduce bleeding, then took a circumferential mucosal cut at the dentate line, connecting from below to the abdominal dissection above.

The specimen — the rectum, the tumour, and the complete mesorectal envelope — was extracted carefully through the anal canal. One critical rule here: no rotation. If the specimen rotates as it comes out, the remaining colon above can twist, which can compromise the blood supply and cause the join to fail. It came out straight.

Four corner stitches were placed first to orientate the anastomosis, followed by the complete coloanal join using 3-0 Vicryl sutures. The operation was complete.

On the Operating Table

✓      Surgery completed in approximately 2.5 hours without major complications

✓      No blood transfusion required

✓      All vital structures — ureter, pelvic nerves, gonadal vessels — preserved intact

✓      External sphincter and puborectalis completely undamaged

✓      Minimal blood loss throughout the entire procedure

The Specimen — Proof That the Cancer Is Gone

After the specimen was removed, Dr. Nayak examined it on the table. The findings told the story:

• Mesorectal fascia: completely intact, not breached at any point — the gold standard of TME
• Distal (lower) margin: greater than 1 centimetre — well above the minimum 1 mm required for cure
• Circumferential resection margin: clear — no tumour touching the outer edge
• Tumour: showed clear evidence of response to chemo-radiotherapy

“This is how a total mesorectal excision specimen should look. The mesorectum is complete — there is no breach in the mesorectal fascia. It is a single glistening layer of fascia covering the entire specimen. The margin of resection is more than a centimetre. She responded very well to chemo-radiation.”

— Dr. Sandeep Nayak, examining the specimen immediately after surgery

For Priya

✓      No permanent colostomy bag — not now, not ever

✓      Anus and external sphincter fully intact — normal bowel function preserved

✓      Tiny keyhole wounds — no large abdominal scar

✓      Bladder and sexual function protected — pelvic nerves undamaged

✓      Cancer removed with wide clear margins — best possible chance of cure

✓      Back home within days — back to her life within weeks

The rectum is the last stretch of the large intestine before the anus. At the very bottom, two concentric ring-shaped muscles work together to give you control over when you go to the toilet. The inner ring is the internal sphincter. The outer ring is the external sphincter. You cannot feel the internal one — it works automatically. The external one is what you consciously tighten when you need to wait.

When rectal cancer grows in the lowest part of the rectum, it typically involves the internal sphincter. For decades, this meant the only surgical option was to remove everything — the rectum, the internal sphincter, the external sphincter, and the anus — and create a permanent opening in the abdomen for waste to leave the body through a bag.

ISR changed this. In ISR, the internal sphincter comes out with the tumour. The external sphincter stays. The colon is joined directly to the remaining anal canal. The external sphincter is enough — with some rehabilitation — to provide a good quality of bowel control. The cancer is gone. The anus works. The bag never appears.

It sounds simple. It is not. The gap between the two sphincters is a few millimetres. The pelvic space is tight, especially after radiation. Getting into the right plane requires experience, patience, and the kind of three-dimensional precision that robotic surgery provides. In the wrong hands, this operation ends in injury. In the right hands — it ends in stories like Priya’s.

Dr. Sandeep Nayak did not stumble into surgical oncology. He chased it — through years of training at some of India’s most demanding institutions, a fellowship in laparoscopic and robotic surgery, and a determination to bring techniques he had seen abroad to patients in Bangalore who needed them.

He is best known as the inventor of RABIT — a scarless robotic thyroid surgery that removes the gland through a hidden incision in the armpit — and RIA-MIND, a robotic approach to neck dissection for oral cancers that leaves no visible scar on the neck. He has performed more than 500 RABIT procedures. He was awarded the KS International Innovation Award for RIA-MIND and the Times Health Excellence Award in 2018.

But behind the innovations and the awards is something more straightforward: a surgeon who keeps asking whether there is a way to take the cancer out while taking less from the patient.

If You Are a Patient or a Family Member

• If you have been told you need a permanent colostomy bag for low rectal cancer — please get a second opinion from a specialist in robotic or laparoscopic colorectal oncology before accepting this. Not every surgeon performs ISR.
• Chemo-radiotherapy given before surgery can shrink a tumour enough to make sphincter-preserving surgery possible, even in very low cancers. It is worth completing the full course.
• An MRI of the pelvis is the most important investigation for deciding whether ISR is an option. If your surgeon has not ordered one, ask why.
• The choice of surgeon is as important as the choice of operation. ISR in inexperienced hands leads to complications and conversions. Ask specifically about experience with sphincter-preserving surgery.
• ICG fluorescence technology during surgery significantly reduces the risk of the anastomosis failing. Ask whether your surgeon uses it.

If You Are a Surgeon

• The da Vinci Xi’s rotating boom allows true single-docking for combined abdominal and pelvic operations — a genuine technical advantage that reduces operative time and repositioning risk.
• In heavily irradiated pelves, anticipate complete loss of natural tissue planes. Approach the dissection slowly, reorient frequently, and use sharp dissection preferentially over energy in adherent zones.
• Table-side perianal finger assessment during the abdominal phase of ISR gives real-time tactile feedback on the depth of distal dissection — a simple safety step that should be routine.
• Specimen extraction through the anal canal must be performed without rotation to prevent conduit twist.
• High ligation of the IMV near the pancreas — not at its junction with the IMA — maximises colon length for a tension-free anastomosis in low pelvic joins.