Weigert-Meyer rule


When complete ureter duplication is present:

  • The ureter which emanates from the superior aspect of the kidney, inserts more inferomedially into the bladder. This is referred to as the ectopic orifice.
  • The other ureter, emanating from the inferior aspect of the kidney, inserts into the bladder more laterally and chephaloid (orthoptic). This ureter is more in keeping with normal ureteric insertion.

Weigert (1877) and later Meyer (1907) recognized that the disposition of the ectopic orifice to lie caudal and medial to the orthoptic orifice was almost universal in cases of ureteral duplication. This was subsequently termed the Weigert-Meyer Law.

The duplication arises during the duplication of the uteric buds, arising from the Wolffian duct (mesonephric duct). The ureters rise superiorly with the formation of the kidney

Kidneys with a double ureter system have been shown to be prone to potential complications, such as collecting system obstruction, ureterocele, lithiasis and vesicoureteral reflux.


1877 Weigert In general an ectopic orifice will lie caudal to the orthotopic orifice

1907 Meyer further described

1946 Meyer claimed that the position of the two orifices was so constant that he formulated a law, the Weigert-R. Meyer law

The situation of the two orifices is generally characteristic insofar as the upper ureter nearly always ends more caudally (Weigert, 1877), and medially (Meyer, 1907), than the lower ureter. This is known as the “Weigert-R. Meyer law.” The upper ureter opens more medially even when both ureteral orifices lie at the same level in the bladder. Since there exist few exceptions to this situation, one should call it a rule instead of a law. The importance of the exceptions is evident but they are so rare that they seemingly stress the rule.

Meyer, Anatomical Record 1946

1958 Stephens pointed out the four published ‘exceptions‘ to the law – Kerr (1911); Mills (1939); Lund (1949); and Dougherty (1954) – and added a further 7 cases of his own.

Associated Persons

Alternative names

  • Weigert-Meyer law
  • Weigert-R. Meyer law


Stephens law: Description of a selected number of cases which do not follow the Weigert-Meyer ‘law’ [ANZ Journal of Surgery. 1958]


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the names behind the name

BA MA (Oxon) MBChB (Edin) FACEM FFSEM. Emergency physician, Sir Charles Gairdner Hospital.  Passion for rugby; medical history; medical education; and asynchronous learning #FOAMed evangelist. Co-founder and CTO of Life in the Fast lane | Eponyms | Books | Twitter |

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