Respected user, hi I evaluated your query thoroughly. *No.of stents are dependent on the no.of blocked arteries. *Inability to put stent in particular artery must be because of high level of narrowing of lumen & inability to negitiate the stent through it , also if other cardiac / anesthetic point of view may be postpone for betterment of patient *Arterial blocking depend on many factors including patient`s cholesterol levels, life style , medications, stress levels, food habits, comorbid conditions, smoking/alcohol consumption , mobility of patient & so on. Hope this clears your query . Thanks for using Health care magic & keeping trust in our medical services wishing him a healthy life ahead. Regards dear take care.