STENTING FOR MALIGNANT OBSTRUCTION OF LEFT COLON INCREASES MORTALITY

NEW YORK (Reuters Health) Feb 01 - A new study says patients who present with malignant obstructions of the left colon fare worse with stenting of the lesion followed by elective surgery than with emergency colectomy.

In an email to Reuters Health, senior author Dr. Jean-Marc Regimbeau, of Jules Verne University of Picardy in Amiens, France, said, "With the conclusions of the paper, we have stopped inserting self-expanding metallic stents."

Dr. Chukwuemeka U. Ihemelandu, a surgeon at MedStar Washington Hospital Center who was not involved in the study, has used self-expanding metallic stents (SEMS) for palliation. He said, "The paper was a good attempt to address an important question."

For years, immediate colectomy has been the standard treatment, but the use of SEMS placed through the tumor is "being presented as a promising alternative," the paper notes. The World Society of Emergency Surgery has recommended it as an option in its guidelines - even though randomized clinical trials comparing stenting to urgent surgery have all been aborted because of excess morbidity due to perforation in patients treated with SEMS.

In the new study, patients who had SEMS attempted were compared to a cohort who had standard emergency surgery. All of the patients who had SEMS procedures were treated in one hospital, and most of those who had immediate surgery were treated in another.

When stents could be placed successfully, a colectomy with anastomosis was done five to 10 days later.

In the standard-care group, patients had emergency surgery consisting of a resection with or without an anastomosis within hours of the diagnosis, or a stoma only followed by a later planned resection.

Altogether, over the 12-year study period, 48 patients had attempted SEMS insertion and 39 had immediate surgery. Baseline patient characteristics were similar except that the immediate surgery group had higher French Association of Surgery mortality scores (p = 0.04) and more cecal perforations at presentation (p=0.006), and the SEMS patients had more synchronous metastases (p=0.006).

Inability to pass a guide-wire meant the SEMS procedure could not be done in four patients. In another two patients, the tumor was perforated, for a technical success rate of 87.5%.

"Our technical success rate is actually better than rates reported in randomized control trials," said Dr. Regimbeau. He noted that a 2012 meta analysis by Tan et al in the British Journal of Surgery reported a technical success rate of 70.7%.

Three patients who had successful SEMS placement suffered subsequent colonic perforations and needed emergency surgery before the planned operation could be done. Those nine patients were included in the SEMS group based on the intention to treat principle.

The duration of follow-up averaged about 30 months in both groups.

The average number of lymph nodes resected was 22 for the SEMS patients vs. 15 in the immediate surgery group (p=0.002). The authors say the difference is likely due to the fact that successful stenting converts an emergency into an elective situation. Dr. Regimbeau pointed out that stent placement allows the obstruction to be treated and patients to be better prepared for surgery.

But in a propensity score matched analysis, five-year survival was markedly worse for the SEMS cohort compared to the urgent surgery group: 25% vs. 62% (p=0.0003). Cancer-specific mortality was also worse at 48% vs. 21% (p=0.02).

Even when patients who presented without synchronous metastases or colonic perforations were excluded from the analysis, the advantage of immediate surgery remained with an overall five-year survival of 67%, compared to 30% for those having SEMS (p=0.001).

Dr. Regimbeau said, "We looked at the data (and) found no other factors that could have had an impact on the outcomes."

Propensity score analysis helps avoid bias. But Dr. Ihemelandu feels that the SEMS patients were sicker on presentation. He said, "I also believe that there is a selection bias favoring the surgery group because the majority of the surgery only group came from a different institution where SEMS was not an option."

The authors, who were originally proponents of the SEMS procedure, now reserve it only for palliative situations and patients with prohibitive operative risks.

Dr. Regimbeau said, "Before starting the study, we were pro stent." But after seeing the results of their study, he and his colleagues would not participate to a randomized control trial as they feel it would be unethical.

Dr. Ihemelandu agreed that a randomized trial of SEMS would not be worthwhile.

The study was published online January 15 in Annals of Surgery.

SOURCE: http://bit.ly/117TKcW

Ann Surg 2013.