How our ideas changedHow our ideas changed
Brearley inserted a needle into the gluteal cleft fat and recorded changes in pressure. He detected a subcutaneous suction pressure of 80mm of water on separating the buttocks. Recovery of the suction pressure was slow and incomplete – 210mm water after 4 separations. This Liverpool surgeon does not mention whether the patient had a pilonidal sinus, what position the patient was in and whether the findings were repeatable.
FIG. 78. -Tracing showing fall in pressure on separating the buttocks four times. 1 mm on the scale represents 26 mm water pressure.
Patey and Scarff from Middlesex Hospital in London observe the scales on hair are so arranged that through friction hair is always propelled in the direction of its root. Once a hair falls into the midline pit, orientation of the scales prevents expulsion of the hair but instead drive the hair further in.
Weale, an anatomist from Westminster Hospital in London, reported a parallel course of shed hairs in 7 patients. Deep ends were club shaped i.e. roots.
But, significant discoveries were not confined to 1955:
Kooistra (in 1942 from St Mary’s Hospital in Michigan) reported that hair was found in the cystic cavity or granulation tissue in 52% of patients. Hair was typically dead and of a fine texture. In only 9% a hair follicle was noted in the sinus.
FIG. 6. Microphotograph of a fairIy well preserved pilonidal sinus showing a minimum amount of infection. To the left a typical hair follicle with an associated sebaceous gland is seen, while on the extreme right, further sebaceous gland tissue associated with the same sinus is noted. Two arrows have been placed to indicate these areas. Within the sinus proper, some epithelial debris and a few dead hairs are seen.
Page (in 1969 also from North Middlesex Hospital in London) placed two hairs into a primary opening of a pilonidal sinus and asked the patient to walk around for 30 minutes. The hair with its root end in the sinus migrated further in while the hair with its root end outside the sinus migrated out.
FIG. 1. The two hairs engaged in the mouth of the sinus at the beginning of the experiment. The root-end of the knotted hair and tip of the other hair are engaged.
FIG. 2. A photograph taken half an hour later, the patient having walked about in the meantime. The knotted hair has worked its way into the sinus. The other hair has been extruded slightly.
BREARLEY R. Pilonidal sinus; a new theory of origin. Br J Surg. 1955 Jul;43(177):62-8.
PATEY DH and SCARFF RW. The hair of the pilonidal sinus. The Lancet. 1955 April;265(6867):772–773.
WEALE FE. The hair of the pilonidal sinus. The Lancet. 1955 Jan;268(6857):230-1.
KOOISTRA HP. Pilonidal Sinuses. The American Journal of Surgery. 1942 Jan;:3-16.
PAGE BH. The Entry of Hair into a Pilonidal Sinus. Br J Surg. 1969 Jan;56(1):32.