Scientists discover groundbreaking facts about human gut mesentery: May radically change the fundamentals of anatomy and embryology and related surgical approaches

In a breakthrough study, a group of doctors and basic scientists from All India Institute of Medical Sciences (AIIMS), New Delhi and Jawaharlal Institute of Postgraduate Medical Research, (JIPMER) Puducherry have laid the long held debate to rest by validating, in human cadavers, that mesentery is a single entity. This debate is continuing since hundreds of years but now (using a revised method of dissection developed by these scientists) they have produced hard evidence of mesentery being a single entity. These findings have been published in a highly reputed journal “Colorectal Disease” with a descriptive video. Mesentery recently caught worldwide attention when a group of Irish scientists proposed it to be a new human organ, a top medical science journal ‘Lancet’ published that proposition.

Mesentery is a double fold of a membrane (called peritoneum) which hangs gut tube from the posterior abdominal wall carrying vessels and nerves. During early development, whole of the intra-abdominal gut tube bears mesentery, but it is thought to degenerate for many gut parts during development. Mesentery has, till now, been regarded as a fragmented entity and present only in some parts of the gut in adult humans. Until the groundbreaking discovery by the team of doctors and basic scientists from AIIMS and JIPMER, the world had not seen what a complete human mesentery looked like. These scientists have shown, for the first time, what precisely the complete mesentery is. These investigators found a continuous mesentery along all parts of intestine and have presented an anatomical specimen description of continuous human mesentery in unprecedented detail extending from duodenum to rectum (first ever anatomical description of complete and intact mesentery).

Mesentery in humans was never known to exist for the duodenum. Its discovery in the duodenum bears historical importance and is a new addition in the discipline of human anatomy. Dr. Ashutosh Kumar, a medical doctor and an expert of Human Anatomy, who is corresponding and lead investigator of the study said “our repeated observations are indicating that duodenal mesentery maybe universally present in all human kind. This research, tentamounts to a paradigm shift in the surgical approaches to this part of intestine.’’

“A continuous mesentery is likely to unravel the mechanism involved in embryological intestinal anomalies leading to obstructions and sometimes giving rise to surgical emergencies. Being highly vascular, it also has a potential role in metabolism of drugs, and an important bearing on a variety of immunological functions and pathogenesis of certain immunological disorders. Our discovery will draw attention of researchers for its potential role in health and disease’’ said Dr. Kumar. He also added, “Although, a mesentery was present in each part of the intra-abdominal gut tube, for some parts it was hiding from the view, and went unnoticed for centuries; attributable to the conservative method of human cadaveric dissection.”

“A continuous mesentery provides a wonderful opportunity for surgeons to follow an avascular anatomical plane around mesenteric sheath to reach different parts of the intra-abdominal gut tube, thereby, simplifying surgical approaches. An ease of access for target part of gut tube and safer route for traversing along mesenteric plane will not only reduce time of surgery but also the morbidity rates due to less chance of bleeding and intraoperative complications”, further elaborated Dr. Kumar.

“Our research has an immense historical significance for human anatomy and medical science. Though this clear evidence of a continuous mesentery may surprise many anatomists, gastroenterologists, and GI surgeons, our findings are the important missing part of Da Vinci’s depictions of the mesentery” explained Dr. Muneeb Faiq, a clinical researcher at AIIMS. Dr. Faiq also added, “An indication of continuous mesentery can be inferred by a sketch of Leonardo Da Vinci, in 1452 and a text description by Toldt in 1879. Then Treves, in 1885, in a series of lectures at Royal College of Surgeons at London expressed the view of a fragmented mesentery in adult human beings. Since then it has been constantly followed by standard anatomy and embryology text books. Our research is first time providing a comprehensive anatomical detail of the complete mesentery along intra-abdominal gut tube in in-situ human cadaveric dissections and retrieved specimens”. Dr Faiq also said that their study has established a concept of fundamental importance in knowledge of human anatomy.

“We are providing a standard method for dissecting complete mesentery in human cadavers, which may be introduced in the standard anatomical and surgical textbooks” said Dr. Vijay, then a senior resident in Department of Anatomy, JIPMER.

Dr. Kamla Kant, Assistant professor in Department of Microbiology at Karaikal campus of JIPMER, reminded of the documented role of immunological cells present in mesentery in pathogenesis of certain functional diseases of intestine in humans like Crohn’s disease, and indicated that a revelation of extensive anatomy of human mesentery would lead to devoted immunological research of this, as of now ignored, body part.  

The team is prepared to submit a further report conducted in larger number of human cadavers to substantiate the universality of these findings, which is likely to inspire radical changes in standard textbook descriptions of human mesentery and relevant dissection and surgical approaches.

‘A relook at the gross anatomy of the mesentery, with respect to its length, continuity and attachments is of great significance, since it can provide better understanding of congenital gastro-intestinal anomalies like malrotation and malfixation of intestines, post its rotation during the embryonic development’ said Dr. Gladwin V. Raj, an Associate Professor at Department of Anatomy, JIPMER.

Prof. Calvin Coffey, a world acclaimed expert on mesentery has described this new publication as an “excellent study in mesenteric science and anatomy”.

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Source of Information:

• Department of Anatomy, All India Institute of Medical Sciences, New Delhi
• Department of Anatomt, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry.
• Etiologically Elusive Disorders Research Network (EEDRN), New Delhi

Journal Reference:

Colorectal Disease  http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1463-1318

Citation:

Kumar, A., Kishan, V., Jacob, T. G., Kant, K. and Faiq, M. A., Evidence of continuity of mesentery from duodenum to rectum from human cadaveric dissection – video vignette. Colorectal Dis. Accepted Author Manuscript. doi:10.1111/codi.13917 http://onlinelibrary.wiley.com/doi/10.1111/codi.13917/full

Video description of composite mesentery demonstration:

https://www.youtube.com/watch?v=pKiTUucRnFQ

https://vimeo.com/229600351