Complex sentence: If the suture or clip is applied too loosely, the occlusion will not be secure, if applied too tightly, blood flow will be impaired, leading to ischemia, necrosis, sloughing and occlusive failure.
Split into simpler sentences: If the suture or clip is applied too loosely, the occlusion will not be secure. If it is applied too tightly, blood flow will be impaired, leading to ischemia, necrosis, sloughing and occlusive failure.