- Dry gangrene primarily results from arterial occlusion, which leads to a significant loss of blood supply to the affected tissue. This ischemia causes the tissue to dry out, shrink, and become mummified without significant bacterial infection or inflammation.
- In contrast, venous thrombosis typically causes wet gangrene due to impaired venous drainage and subsequent infection.

Therefore, arterial occlusion is the key factor in dry gangrene's pathogenesis.

Reference: Robbins Basic Pathology, 10th Edition, Chapter 3: Cell Injury and Death