Exérese de quisto pilonidal sacrococcígeo (Revisão)

"Fernando este quisto é o mesmo que QSC ?
Se for tens 2 orientações de codificações  em mails diferentes"


(Responde Fernando Lopes)
 
 
De facto já me pronunciei de modos diferentes sobre a codificação do procedimento de exérese de quisto sacrococcígeo (QSC).
A orientação de 11-10-2017 não estava correta, ao contrário da resposta que enviei depois, em 20-12-2017.
E a diferença esteve na body part: é uma exérese de lesão da pele ou do tecido subcutâneo?
Para responder às dúvidas que foram levantadas tentei verificar a natureza do QSC e, consequentemente, a codificação da sua exérese.
Algumas citações do que encontrei:

"... today, pilonidal disease describes a spectrum of clinical presentations, ranging from asymptomatic hair-containing cysts and sinuses to large symptomatic abscesses of the sacrococcygeal region that have some tendency to recur."

"It has been postulated that hair penetrates into the subcutaneous tissues through dilated hair follicles, which is thought to occur particularly in late adolescence, though follicles are not found in the walls of cysts. Upon sitting or bending, hair follicles can break and open a pit. Debris may collect in this pit, followed by development of a sinus with a short tract, with a not clearly understood suction mechanism involving local anatomy, eventually leading to further penetration of the hair into the subcutaneous tissue. This sinus tends to extend cephalad, likely owing to mechanical forces involved in sitting or bending. [5] A foreign body-type reaction may then lead to formation of an abscess. If given the opportunity to drain spontaneously, this may act as a portal of further invasion and eventually formation of a foreign body granuloma. Infection may result in abscess formation."

"The primary incision is longitudinal and should be made off the midline into skin, subsequently carrying it down to the level of subcutaneous tissue to open up the abscess cavity. As much purulent drainage and debris should be removed from the site as possible; blunt dissection may assist with this process as the patient can tolerate."~~

in: Pilonidal Cyst and Sinus Treatment & Management: https://emedicine.medscape.com/article/788127

Parece, assim, ser evidente que tanto a anatomia dos quistos como o procedimento do seu tratamento atingem o tecido subcutâneo. A body part a selecionar na ICD-10-PCS será então a Subcutaneous Tissue and fascia. 
Socorrendo-nos das Guidelines:
 
Guideline B3.5 Overlapping body layers
If the root operations Excision, Repair or Inspection are performed on overlapping layers of the musculoskeletal system, the body part specifying the deepest layer is coded. Example: Excisional debridement that includes skin and subcutaneous tissue and muscle is coded to the muscle body part.
(Entre a pele e o tecido subcutâneo seleciona-se este por ser o mais profundo)
 
Convention A10
“And,” when used in a code description, means “and/or.”
Example: Lower Arm and Wrist Muscle means lower arm and/or wrist muscle.
(Não há que duvidar na escolha do body system Subcutaneous Tissue and fascia porque não é necessário que o procedimento atinja a fáscia: basta que atinja o tecido subcutâneo... subcutaneous tissue and / or fascia).
 
A construção do código para o procedimento de exérese de um quisto sacrococcígeo utilizará a tabela 0JB e a body part 9 Subcutaneous Tissue and Fascia, Buttock
A approach será Open ou Percutaneous de acordo com o tamanho da incisão: