Eva AngeneteESCP’s topic of the month for February is Sigmoid Volvulus. We caught up with Eva Angenete to talk about why this is a key area for further research. 

Eva Angenete is Associate Professor of Surgery at the University of Gothenberg in Sweden. Last year Dr Angenete won the Swedish Surgical Society’s Major Research Award for her work on colorectal cancer.

Dr Angenete recently published a new paper - 'Recurrence Risk of Sigmoid Volvulus'. The study was a single centre cohort study which reviewed treatment and assessed the outcome of sigmoid volvulus in adult patients treated at a Swedish university hospital.

Q. What do we know about Sigmoid Volvulus?

Sigmoid volvulus is a cause of large bowel obstruction and occurs when the sigmoid colon twists on its mesentery, the sigmoid mesocolon. The reasons why this twisting happens remains largely unknown. It is more common amongst older patients and especially when patients have co-morbidities. 

It is a condition that all general and colorectal surgeons need to be familiar with as it often presents at emergency departments.

Sigmoid volvulus is troublesome for the patient and it is also a condition that consumes health care because it is a condition with a tendency to recur if treated conservatively. The mortality remains considerable with studies evaluating the rate at 2-15%, depending on the circumstances of the surgery.

Q. Why was it important for your study to look at recurrence rates?

It is possible to treat patients many times with endoscopy or a rectal tube but when we do that many patients have a recurrence, often within two or three months. We could save these patients from experiencing these painful recurrences and reduce the burden on health services by referring them for elective surgery earlier. As emergency surgery is associated with higher risk of mortality it is also important to try to operate as many of these patients as possible in the elective setting.

This is not a malignant condition and therefore often these patients are not prioritised and are further down waiting lists. Before they can have the elective surgery they have a recurrence and require emergency treatment again. In Sweden it would be preferable if we could operate on these patients sooner to reduce the unnecessary re-admissions.

Q. What has changed in the treatment of sigmoid volvulus in the last 10 years?

The biggest changes in the last decade have occurred primarily at the diagnostic stage. Almost all patients are now diagnosed with a CT scan, which gives a more accurate diagnosis up front than previously.

Most of the patients are very sick at diagnosis and so a prompt and early diagnosis is of utmost importance.

Previously many patients were treated with a barium enema but many surgeons now would advocate for using endoscopy instead.

This gives surgeons a much better opportunity to evaluate the bowel compared to using an x-ray. Using this technique bears the advantage of visualising the mucosa to rule out necrosis.It does mean that the surgeons or gastroenterologists have to have access to sigmoidoscopy 24-7, which may not always be possible.

Q. What advances do you hope to see in the treatment in next 10 years?

Hopefully we will be more active in deciding which patients to operate on in an elective setting to reduce the risk for recurrence. In the study I published last year we had indications that the risk of recurrence is less after the first episode, so perhaps not all patients would benefit from a resection. However, it indicated that after the second episode it is possible that most patients who are fit enough for surgery would benefit from an elective setting, rather than being operated on as an emergency case after yet another recurrence.

Q. What are the key debates in the treatment of this condition?

The key debates probably lie in the use of endoscopy for decompression compared to barium enema or rectal tube insertion (most often performed by the radiologist) as well as the timing of elective surgery.

The endoscopic technique has enabled the evaluation of the mucosa, identifying patients with gangrene and more severe conditions. This may improve the outcome with less morbidity and mortality as patients will be identified sooner.

However, in the material from our own hospital, this did not seem to be of importance. On the other hand, in the research of Dr Atamanalp using data from more than 1000 patients suggested that including the evaluation of gangrene in the mucosa may be helpful in the selection of treatment.

Best practice for elective surgery is to perform a laparoscopic sigmoidectomy after endoscopic or radiologic decompression. If possible it is advantageous to move the patient from the emergency to elective setting. The mortality in the emergency setting is high. In our study we found that mortality after planned surgery following successful decompression was 3.3% compared to 13% following emergency surgery. It is somewhat difficult to rule out that this is due to several confounding factors, but the facts remains that elective surgery is associated with much lower mortality.

Further information

Eva Angenete’s presentation on Modern Management of Sigmoid Volvulus