Development of a Standardized Nomenclature for Bronchoscopy of the Respiratory System of Harbor Porpoises (Phocoena phocoena)
Abstract
Stranded porpoises and dolphins are rehabilitated at oceanariums following illness or
injury from a variety of causes such as infections, toxins, trauma from net entanglement, boat strikes, or
other fisheries interactions. Respiratory disease has been recognized as the leading cause of death among
captive dolphins for the last two decades2. Early detection of cetacean respiratory disease is
difficult but essential for its successful treatment3.
Bronchoscopy is a promising technique for the early detection of respiratory illness in
cetaceans and has been successfully used in the bottlenose dolphin3,4. However, since bronchial
airway sizes differ among cetaceans of different ages and species, more information is needed regarding types
of bronchoscopes appropriate for diverse cetacean patients. Refinement of cetacean bronchoscopy also requires
development of a nomenclature system to facilitate description of the anatomic site at which lesions occur.
This allows precise identification and monitoring of respiratory lesions and accurate communications between
veterinarians.
The goal of this research was to adapt the dog and horse nomenclature system devised by
Amis, McKiernanl and Sweenys to the harbor porpoise (Phocoena phocoena). Silastic and air dried models
of the bronchial tree were made to illustrate the anatomy, devise the nomenclature and describe the most
appropriate bronchoscopes.
Five harbor porpoise lungs were removed from their carcasses. The endobronchial anatomy
was observed and filmed through a 9.5mm GIF-100 Olympus video Gastroscope inserted at the larynx. From 4
inflated, air-dried lung specimens, a flexible plastic mold of the bronchial airways was made. The permanent
mold was made using Dow Corning Silastic E with 40% radio-opaque barium. A dorsoventral radiograph was taken
of the lung containing the Silastic E/barium mold. The lung tissue surrounding the cast was dissolved by
placing the lung in Clorox and measurements (position, length and diameter) of the plastic cast were taken
with a 6-dial. caliper. The branching patterns of lobar and segmental bronchi were identified through
combined use of videoendoscopy, radiographs, and study of Silastic molds. Following identification of
bronchial anatomy in these specimens, the Amis and McKiernan nomenclature was adapted to the harbor porpoise
lung in the same way Sweenys adapted this nomenclature to the horse.
In the nomenclature system developed by Amis and McKiernan for the canine, the lobar
bronchi are named according to the order of their emergence from the primary bronchi. Additionally, the side
of the primary bronchus from which the lobar bronchi originate is incorporated into the nomenclature. The
harbor porpoise lung has 3 major primary bronchi while the domestic dog has two. The porpoise possesses a
right tracheal bronchus and the right and left primary bronchus are common to both species. The nomenclature
of Amis and McKiernan was readily applied to the porpoise lung. In 4 of the 5 lungs studied, the lobar
bronchi originated from the principal bronchi in the same order and in the same approximate anatomic
location. Both wild cetaceans and those in captivity will benefit from the development of lung models and
standardized bronchoscopic techniques for research and description of respiratory disease. Since most
bronchoscopy of cetaceans is performed with little or no anesthesia, the duration of the examination must be
minimized. Plastic casts of porpoise lungs allow the bronchoscopist to study and anticipate bronchoscopic
findings, facilitating efficient exams. Development of a standardized nomenclature for cetaceans will promote
consistency in the description of respiratory illness, fulfilling the need for standardized reproducible
criteria for diagnosis and treatments.
Acknowledgements
This work was supported by a fellowship from the Geraldine R. Dodge Foundation,
Frontiers for Veterinary Medicine. The authors would like to thank the New England Aquarium for providing us
with the Harbor Porpoises, Dr. Larry Kleine, Dr. David Sherman, Mrs. Sheila Moffat, Dr. Richard M. Jakowski,
Ms. Gillian Sanders, Mr. Bob Brown, Mr. Brian Delgiudice, Dr. Tecumseh Fitch, Mr. Evan Mead and Tufts
University Wildlife Clinic for their expertise and assistance during the course of this project. This
presentation was supported by Abbott Diagnostic Laboratory Animal Health Division and Waltham USA Pet Foods.
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