Which of the following is key for determining the effectiveness of coaptive techniques in hemostasis?

Duration of energy delivery is a critical factor in determining the effectiveness of coaptive techniques in hemostasis because it directly influences the thermal injury created in the tissue. When using devices that deliver energy, such as electrosurgical devices, the length of time that energy is applied can affect the extent of tissue coagulation and the formation of a stable clot. Appropriate timing helps to ensure that enough heat is delivered to achieve hemostasis without causing excessive damage to surrounding tissues, which is essential for minimizing complications and promoting healing.

In contrast, while the other options may have their own significance in specific scenarios, they do not play as pivotal a role in the overall effectiveness of hemostatic techniques as the duration of energy delivery does. The probe's temperature, the electrode's shape, and the type of endoscope may influence the procedure in certain contexts, but the key determinant in achieving effective hemostasis lies in controlling how long the energy is applied to the tissues.