Nomenclature, filling and angioarchitecture of lymph vessels in organs. Scanning electron microscopy of the stomach of the turtle Pseudemys scripta elegans using different injection methods.

The gastric lymph vessel network of Pseudemys scripta elegans shows all the characteristics of initial lymphatics. A differentiation of initial lymphatics in lymphatic capillaries and precollectors is not possible in the turtle. The scanning electron microscopic examination shows that ultrastructural analysis of initial lymphatics is possible after manual subserous injection of glutaraldehyde or application with the vacuum chamber. In the stomach of the turtle all characteristics of initial lymphatics (interendothelial openings, subendothelial filaments, connective tissue trabeculae and endothelial bridges) could be demonstrated. Only valves were absent. The situation is similar in mammals including man. The most important filling phenomenon is a horizontal spreading of fluid in the lymphatics.

Vacuum injection--a new indirect fixing method for the demonstration of initial lymphatics in biopsy specimens of human organs.

With the indirect vacuum injection method (IVIM) at a negative pressure of 30 kPa, it is possible to demonstrate the initial lymphatics (IL) by scanning electron microscopy even in biopsy specimens of various organs (minimum size 0.5 X 0.5 cm2). IL can also be dilated and fixed using the indirect perfusor injection method (IPIM), but only in larger specimens (minimum size 2.0 X 2.0 cm2). Only dilated IL can be examined by scanning electron microscopy, and only the IL of the ampulla of the Fallopian tube can be reliably dilated during immersion fixation. The quality of fixation on use of the vacuum technique conforms to the standard achieved with other methods. No one has yet succeeded in demonstrating the IL in biopsy specimens smaller than mentioned above using any of the methods described.

New techniques of demonstrating lymph vessels in skin biopsy specimens and intact skin with the scanning electron microscope.

Two new methods now allow the systematic examination of the morphology and micropathology of the initial lymphatics (lymph sinuses and precollectors) in human skin biopsy specimens under the scanning electron microscope. Pertinent studies and findings in the intact skin of anesthetized pigs demonstrate the standard quality of the biopsy preparations. The following are new findings made with these methods: in the skin of the human head, both the lymph sinuses and the precollectors extend as far as the epidermis. The opening apparatus of these vessels consists not only of anchoring filaments and interendothelial openings, but also of endothelial bridges and trabeculae. The interendothelial openings can be present in three types of transformation (Type I-III). As part of these studies, an attempt was made to standardize the lymphological nomenclature so that it would be acceptable to both anatomists and clinicians.