Triangle of Calot

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A Moment in History

William S. Halsted, MD
(1852 – 1922)

American anatomist, teacher, and surgeon, William Stewart Halsted was born in New York City, USA to a wealthy family of English origin. His father was involved in charitable work and Governor and trustee to a city hospital. Not a brilliant student initially, Halsted took an undergraduate in Liberal Arts in Yale, CT., after which he entered the Medical College of Physicians at the Columbia College, where he excelled.

As a second-year medical student Halsted applied and obtained a position in surgery at a local hospital. In here he learned about Lister’s antiseptic technique and became an adamant proponent of it to reduce infection. In 1877 Halsted obtained his MD. After a short time as House Physician at the New York Hospital, Halsted traveled to Europe to further his education studying for two years at the Universities of Vienna, Leipzig, and W?rzburg.

Besides being at the forefront of surgical and antiseptic techniques (introducing the use of rubber gloves in surgery), Halsted was extremely concerned with the way medical students were taught in the US. He pioneered bedside clinical round discussions with the medical students after two years of basic sciences studies. Halsted developed the idea of a patient chart; he also developed the residency program for medical students in use today.

Halsted is probably the most influential researcher and surgeon at the turn of the century. He dedicated time to the study of intestinal anastomoses and the use of silk as a suture material. His experimental work in 1887 proved that the inclusion of the submucosa layer in an anastomosis was mandatory, as well that a single layered anastomosis was enough to attain closure. Perhaps Halsted’s most important contribution was the application and use of the scientific method to surgical questions. Halsted’s principles, also known as "Halsted's Rules of Surgery", set the standards used today in surgical suturing and surgical stapling.

He also pioneered the development and surgical techniques for radical mastectomy as a treatment for breast cancer.

As a side effect of this studied in anesthesia and the use of cocaine for anesthesia, Halsted became addicted to this substance, a problem that followed him through the years. Without impairing his capacity as a researcher and a surgeon, Halsted eventually recovered. He died in Baltimore in 1922 as a complication to surgery.

Sources:
1. Dubay, A. D., & Franz, G. M. (2003). Acute Wound Healing: The Biology of Acute Wound Failure. Surg Clin NA, 83, 463-481.
2. Halsted, W. S. (1887). Circular Suture of the Intestine - An Experimental Study. Am J Med Sci, 436-461.
3. “William Stewart Halsted: his life and contributions to surgery” Osborne, P. Lancet Oncol 2007; 8: 256–65
4. “William Stewart Halsted: Surgical pioneer” Burress, P Endoc Today (2010), 8: (2) 22
5. “William Stewart Halsted (1852–1922) Neurological stamp” Haas, LF J Neurol Neurosurg Psych 2000;69:641
Original image courtesy of "Images from the History of Medicine" at www.nih.gov

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Details: Written by: Efrain A. Miranda, Ph.D.; Published: May 10, 2016; Hits: 70484

Image modified from the original
(Singh and Ohri, 2006

The [triangle of Calot], also known as the “cystohepatic triangle” is a triangular region found within the lesser omentum connecting the duodenum, stomach, and liver. It is an area bound superiorly by the inferior surface of the liver, laterally by the cystic duct and the medial border of the gallbladder, and medially by the common hepatic duct.

The surgical importance of this area is for a cholecystectomy. It is within this area that the surgeon will usually find the cystic artery, a critical structure that needs to be ligated in this procedure. I stress the term “usually” as the hepatobiliary tree is one of the areas in the human body that has the most anatomical variations. In fact, the anatomy in this region is considered to be “normal” only in 64% of the cases. The cystic artery may not be found in the triangle of Calot therefore careful dissection and identification of the structures is needed in every surgery.

The above description of the triangle of Calot is what some refer to as the “modern triangle of Calot”, as the original triangle described by Dr. Jean-Francois Calot (1861 – 1944) is different.

Calot’s original description of this triangle is: “Le triangle n’est pas exactement équilatéral, mais plutôt isocéle, les deux cotés supérieur et inférieur, représente par l’artére et le conduit cystique, étant seuls égaux, et un peu plus longs que la partie du canal hépatique qui entre dans la constitution du triangle’’ , which can be translated as: “ The triangle is not exactly equilateral, but rather an isosceles triangle. The superior and inferior sides, represented by the cystic artery and cystic duct, are equal and a little longer than the part of the hepatic duct, which enters into the formation of the triangle. (Abdalla, 2013).

In the accompanying image Calot’s original triangle is shown by horizontal blue lines while the modern version of the triangle of Calot is shown with vertical red lines.

Sources:
1. “Calot's triangle” Abdalla S, Pierre S, Ellis H. Clin Anat. 2013 May;26 (4):493-501
2. “Anatomic landmarks: their usefulness in safe laparoscopic cholecystectomy” Singh, K; Ohri, A. Surg Endosc (2006) 20: 1754–1758
3. “Surgical Anatomy” Deaver, J P. Blakiston's Son & Co. Philadelphia, 1901
4. "Tratado de Anatomia Humana" Testut et Latarjet 8th Ed. 1931 Salvat Editores, Spain
Image modified from the original (Singh and Ohri, 2006. Pastel sketch by Dr. E. Miranda

Triangle of Calot

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