Clinical Trial: Piecemeal Versus En Bloc Resection of Large Rectal Adenomas

Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Interventional

Official Title: Piecemeal Versus En Bloc Resection of Large Rectal Adenomas -A Prospective, Randomized Multicenter Study

Brief Summary:

Currently, colonoscopy is the safest way to detect bowel tumors and polyps, since these can be biopsied and removed in one working process. If the size of adenomas is larger than 2 cm, resections are usually done in a hospital setting. For the resection of large adenomas, different approaches can be used. The so-called piecemeal resection is done with snares, to cut off parts of the adenoma piece by piece until the whole adenoma is resected. This technique is the standard therapy, but is not required for very large adenomas, which can often show cell alterations that indicate cancer. Therefore these adenomas should be resected in one piece. This is done by the so-called en-bloc resection. For this kind of therapy, different endoscopic knifes are use to cut off the adenoma as a whole. Both resection techniques are done usually by previous injection of saline or other liquids to elevate the lesion from its bottom tissue.

Although the piecemeal resection of large adenoma is the standard therapy, it shows recurrence rates of 10 to 25%, which afford repeated therapies and follow up controls. En-bloc resections, though, are expected to have less recurrence rates but are much more complex to perform. They have higher complication rates especially in the West, where it has bee introduced only a couple of years ago.

The data situation regarding safety and efficacy of both therapies is low. This study is the first one ever to compare piecemeal EMR and ESD in a randomized way. The study might have influence on the logistics of future adenoma processing and patient flow.

Detailed Summary:

In 20 to 35% of colonoscopies due to symptoms or for prevention polyps, so-called adenoma, are found. Currently, colonoscopy is the best way to detect bowel tumors and polyps, since these can be biopsied and removed in one working process. If the size of adenoma is larger than 2 cm, resections are usually done in a hospital setting. Foremost for flat adenoma, the resection by snares piece by piece, the so-called piecemeal polypectomy, or piecemeal endoscopic mucosal resection (EMR), is state of the art. Resection will usually follow a submucosal saline injection (saline assisted polypectomy). Recurrences occur in 10 up to 25 %, requiring a reapplication of endoscopic therapy and follow up examinations.

Depending on the size of adenoma, increasing amounts of cell alterations of an advanced stage such as high grade dysplasia / intraepithelial neoplasia (HGIN) up to early cancer are found. In these cases, for histo-pathological and oncological reasons, a resection in a solitary manner (en-bloc resection) is necessary to evaluate the completeness of resection properly. Also, former studies showed that recurrence rate could be decreased considerably by en-bloc resections, since the aim is to perform a complete resection basally and laterally. New endoscopic techniques of en-bloc resections have been introduced since a couple of years, using several endoscopic knifes to cut adenoma down after submucosal injection of liquid and consecutively dissect it from the tissue underneath. This technique is mostly called endoscopic submucosal dissection (ESD), and, with not too large adenoma, can be combined with snare resection, too. The complexity of this method though is much larger than that of snare resection. Therefore, the western success rate is considerably less than in Japan, where it was developed first, and where higher numbers of cases exist in the upper GI tract as well as i
Sponsor: Universitätsklinikum Hamburg-Eppendorf

Current Primary Outcome: success rate of complete resection [ Time Frame: 6 and 18 months after primary therapy ]

Original Primary Outcome: Same as current

Current Secondary Outcome:

• en-bloc group: rate of R0 resections [ Time Frame: timeline 0, day of en-bloc resection ]
  This parameter is regarding histopathology. Since piecemeal resections do not allow such a diagnosis, this parameter is only for the en-bloc resected group.
• recurrence rate after complete adenoma resection [ Time Frame: 36 months after initial resection ]
  Since early recurrences can evolve from leftover tumor cells and will become manifest after a time, the third control after two controls with negative biopsies.has been chosen to be the gold standard.
• progress of therapy in patients with incomplete resection and recurrences [ Time Frame: 36 months after initial resection ]
  patients will be treated further according to treatment standard depending on endoscopical and histological findings
• differences in the subgroups of adenomas [ Time Frame: 5 years ]
  size, shape according to nice classification, low-grade and high grade intraepithelial adenomas, sm1 carcinomas
• required time for the initial procedure [ Time Frame: timeline 0, day of initial resection ]
  for piecemeal resections including second procedure with APC therapy
• complications including success of complication management [ Time Frame: 5 years ]

  rate of complications that need intervention, e.g.

  • perforation (intra - and post procedural, surgery, additional procedures such as antibiotics, monitoring, intensive care
  • secondary haemorrhage (second look endoscopy, surgery)
  • infection
• complications through patient sedation [ Time Frame: timeline 0, day of initial resection ]
  depending on sedation standards of the participating centers
• resolution of tumor board for post resections and outcomes of patients with carcinoma histology [ Time Frame: 5 years ]
  patients with carcinoma histology will be discussed by a of tumor board

Original Secondary Outcome:

• en-bloc group: rate of R0 resections [ Time Frame: timeline 0, day of en-bloc resection ]
  This parameter is regarding histopathology. Since piecemeal resections do not allow such a diagnosis, this parameter is only for the en-bloc resected group.
• recurrence rate after complete adenoma resection [ Time Frame: 36 months after initial resection ]
  Since early recurrences can evolve from leftover tumor cells and will become manifest after a time, the third control after two controls with negative biopsies.has been chosen to be the gold standard.
• progress of therapy in patients with incomplete resection and recurrences [ Time Frame: 36 months after initial resection ]
  patients will be treated further according to treatment standard depending on endoscopical and histological findings
• differences in the subgroups of adenomas [ Time Frame: 5 years ]
  size, shape according to nice classification, low-grade and high grade intraepithelial adenomas, sm1 carcinomas
• required time for the initial procedure [ Time Frame: timeline 0, day of initial resection ]
  for piecemeal resections including second procedure with APC therapy
• complications including success of complication management [ Time Frame: 5 years ]

  rate of complications that need intervention, e.g.

  • perforation (intra - and post procedural, surgery, additional procedures such as antibiotics, monitoring, intensive care
  • secondary haemorrhage (second look endoscopy, surgery)
  • infection
• complications through patient sedation [ Time Frame: timeline 0, day of initial resection ]
  depending on sedation standards of the participating centers
• resolution of tumor board for post resections and outcomes of patients with carcinoma histology [ Time Frame: 5 years ]

Information By: Universitätsklinikum Hamburg-Eppendorf

Dates:
Date Received: September 4, 2014
Date Started: April 2014
Date Completion: June 2019
Last Updated: May 5, 2017
Last Verified: May 2017