A method for obtaining a full thickness biopsy of the wall of a hollow organ, comprising obtaining an apparatus comprising a cannula comprising a proximal cannula end comprising a cutting edge and a distal cannula end comprising a biased spring, the biased spring being coupled to a needle carrier and a releasable lock and a needle disposed within the cannula and carried on the needle carrier, the needle comprising: a tip a flange a notch portion comprising a notch thickness and a shaft comprising a shaft thickness where the shaft thickness is greater than the notch thickness and the releasable lock is configured to hold the cannula in a withdrawn position relative to the needle obtaining a patient having skin, a first wall, and a second wall creating an incision through the skin of the patient inserting the apparatus into the incision advancing the apparatus through the first wall and the second wall withdrawing the cannula relative to the needle locking the cannula with the releasable lock aligning the notch portion such that the notch portion straddles the second wall releasing the releasable lock such that the cutting edge of the cannula passes completely through the second wall creating a full-thickness biopsy and withdrawing the apparatus from the patient.
