Author: Professor Guy Maddern

General Surgery

Summary
A 64-year-old man was referred by his treating surgeon for rectal bleeding and significant weight loss. He was an inpatient due to exacerbation of his chronic obstructive pulmonary disease (COPD). Additional comorbidities included ischaemic heart disease, hypertension, a pacemaker and home oxygen.

A colonoscopy was performed and a lesion identified 10 cm above the anal verge. The lesion was partially excised by snare excision. Subsequent pathology revealed adenocarcinoma. A transanal minimally invasive surgery (TAMIS) procedure was recommended by the referring surgeon (in the absence of available imaging) to completely excise the residual cancer and determine the depth of invasion. A transanal procedure was considered because the patient was thought unfit for laparotomy. Preoperative staging by Magnetic Resonance Imaging (MRI) was impossible because of the patient’s pacemaker.

The tumour was described as anterior and higher (5 cm above sphincters) than first thought. Despite this, the TAMIS procedure went ahead. It was not possible to maintain the pneumorectum, and on inspection of the collapsed rectum there was visible peritoneum and small bowel present. A laparoscopy was undertaken and a large defect in the rectum identified. Ultimately, a lower midline laparotomy was performed and a low Hartmann’s procedure undertaken in an operation lasting four hours 45 minutes. Postoperative histologic evaluation of the resected surgical specimens revealed a T3 adenocarcinoma, implying full thickness penetration of the tumour through the rectal wall into the perirectal fat.

There were several postoperative problems including hypotension, acute pulmonary oedema and several hypoxic episodes. On postoperative day 4, a care conference was held with the patient, along with his daughter and appropriate surgical and intensive care unit (ICU) specialists. At the patient’s request active treatment was withdrawn and he was transferred to palliative care. He passed away two days later.

Discussion
Several clinical features of this case suggest that the choice of operation—TAMIS—to manage what was an anterior mid-rectal cancer, was highly likely to produce rectal perforation necessitating further treatment. For a patient such as this, the anterior peritoneal reflection typically lies seven to eight centimetres (cm) from the anal verge. The tumour lay 10 cm above the anal verge. Given that the lesion was proven adenocarcinoma, a full thickness excision was required. Under these circumstances, full thickness rectal perforation during TAMIS is so likely that this might have been discussed in much greater detail with the patient and his daughter beforehand. A management plan should have been put in place should such an event occur.

While a low Hartmann’s procedure is considered to be the appropriate operative choice once the rectal perforation had occurred, this committed the patient—who had already been deemed unfit for laparotomy—to a major abdominal procedure lasting close to five hours. Under these circumstances, a complicated postoperative course was to be expected. Although the patient may have survived with further ICU treatment, after a four-day period of such intensive care the patient and his family requested withdrawal of active treatment and the institution of palliation.

It is most likely that the magnitude of the operation required to deal with the full thickness rectal perforation following the TAMIS excision, resulted in the postoperative complications that arose. Given the prior anaesthetic assessment that the patient was unfit for laparotomy, these complications were directly responsible for the patient's death.

An alternative choice of treatment would have been more prudent. Once the perforation occurred, direct repair of the rectal perforation by suture using the TAMIS technique could have been undertaken and a relatively straight-forward laparoscopic elevation of a loop ileostomy performed. This would have been a far simpler operation of a considerably lower order of magnitude than the one that was undertaken and may have led to fewer and less serious postoperative complications than the ones that arose.

Although it might appear that the patient had no choice but to undergo surgical excision of the rectal cancer, a transanal attempt at excision was always likely to result in rectal perforation. This likelihood may have been better anticipated at the time of the initial examination under anaesthetic. At this time the decision could have been made not to proceed to surgery of that nature, in favour of further discussions with the patient and his family about a course of palliative radiotherapy for the residual rectal tumour. While the outcome of such radiotherapy in any given individual is not predictable, there is good evidence that many such patients do respond to treatment for a reasonable period of time. Given that this patient's overall longevity was clearly limited by his medical comorbidities, this may well have been a therapeutic option worth considering in more detail.

Conclusion
The location of this tumour meant that full thickness excision was highly likely to cause rectal perforation. It may have been worthwhile not proceeding to surgery and instead discussing with the patient and family the alternative option of palliative radiotherapy.