What are some issues that can cause hair transplant failure and how common are they?

I can understand your frustration after going through two transplants with mixed results. There are several factors that can influence the success of a hair transplant, and while surgeon skill is a key part, certain patient-specific factors can also play a significant role in outcomes. Here are some common issues that can cause hair transplant failure:
Poor Blood Supply: Areas of the scalp that have poor circulation might not be able to nourish the transplanted grafts properly, leading to failure in some areas.
Scalp Conditions: Conditions like scarring, excessive oil production, or inflammation can interfere with graft survival. Even minor scalp issues that might not seem significant can create a less favorable environment for grafts to take.
Pre-existing Hair Loss Progression: Hair loss doesn’t stop after a transplant, so if your hair loss is still progressing despite medication like finasteride, it can affect the results over time. This is why long-term planning and maintenance are important.
Graft Handling and Placement: While you trust your surgeon, there are factors in graft survival, such as how the grafts are handled, how long they’re outside the body, and how they’re placed. Even when following post-op instructions perfectly, these technical aspects can affect outcomes.
It’s not extremely common for transplants to fail entirely, but patient-specific factors like these can cause variability in results. If one temple responded well and the other didn’t, it could be a combination of these elements at play. Since your surgeon has offered to fix the issue, it shows they’re committed to making sure you get the result you want.