Complications in Hair Transplantation: Prevention and Management

I. Course Introduction

This course aims to systematically review the various complications that may occur during and after hair transplant surgery, providing an in-depth analysis of their causes, clinical manifestations, treatment methods, and preventive measures. Through this course, it is expected to enhance everyone’s understanding and management capabilities regarding hair transplant complications, further standardize clinical operations, ensure medical safety, and improve patient satisfaction.

II. Overview of Hair Transplant Techniques

Currently, the mainstream hair extraction methods in hair transplantation primarily include Follicular Unit Extraction (FUE) and Follicular Unit Transplantation (FUT, commonly referring to the strip method). Both techniques have their own advantages and disadvantages. This material will focus on the potential complications associated with these techniques, without delving into excessive detail about the planting methods themselves.

III. Classification of Hair Transplant Complications

Complications of hair transplantation can be broadly classified based on their time of occurrence into intraoperative complications and postoperative complications. Postoperative complications can be further subdivided into early complications (typically within 7 days post-surgery) and mid-to-late-term complications (typically after 7 days post-surgery). This material will be structured according to this timeline.

IV. Intraoperative Complications

1. Allergic Reaction

Clinical Manifestations:

Although rare, it is extremely dangerous if it occurs. The patient may experience symptoms such as sweating and pale complexion; severe cases can lead to anaphylactic shock.

Timing of Occurrence:

Mostly occurs during the injection of local anesthetic. If there is no reaction within ten minutes after the anesthetic injection is completed, the risk of subsequent occurrence is low.

Etiology:

Mainly due to allergy to local anesthetics (e.g., lidocaine).

Treatment:

Immediately stop medication and surgical operation. Administer anti-allergic treatment based on the severity of the allergic reaction, such as oxygen, epinephrine, corticosteroids, and symptomatic treatment.

Prevention:

• Thoroughly inquire about the patient’s allergy history, especially drug allergies, before surgery.
• During the surgical process, especially when the patient is in a prone position for FUE, maintain continuous communication with the patient and closely observe their reactions.
• Pay attention during the anesthetic injection process; if abnormalities occur, address them promptly.

2. Syncope

Clinical Manifestations:

The patient suddenly feels dizzy and weak.

Timing of Occurrence:

Mostly occurs during or some time after the anesthetic injection.

Etiology:

• Fasting before surgery: Some patients mistakenly believe they cannot eat breakfast before surgery.
• Hypoglycemia or pre-existing blood sugar issues.
• Postural hypotension.
• Nervousness and anxiety.

Treatment:

Immediately stop the operation, have the patient lie flat, loosen their collar, and maintain an open airway. Administer oxygen if necessary and monitor vital signs.

Prevention:

• Preoperative education, informing patients that they can eat breakfast normally.
• Pay special attention to patients with a history of hypoglycemia or postural hypotension.
• Provide psychological counseling to the patient before surgery to alleviate tension.
• Perform a gentle operation during surgery to avoid excessive stimulation.

V. Early Postoperative Complications (Within 7 Days Post-Surgery)

1. Edema

Clinical Manifestations:

Very common. Usually manifests as swelling in areas such as the forehead, periorbital region, and eyebrow region; severe cases may affect eye-opening. May be accompanied by bruising.

Timing of Occurrence:

Generally appears and gradually worsens 48 to 72 hours post-surgery, then begins to subside after a few days.

Etiology:

• Surgical trauma.
• Excessive injection or too deep a level of tumescent solution: For example, if injected into the subgaleal space (this space is connected to the skull) during head injections, the tumescent solution can easily spread forward along the space, leading to forehead edema.
• Excessive volume of tumescent solution injected.

Treatment:

• Local ice application in the early stage (within 24-48 hours).
• Use corticosteroids or anti-swelling drugs (e.g., Aescin / Sodium Aescinate) as prescribed.
• Rest with the head elevated.

Prevention:

• Control the injection level (should be subcutaneous, avoiding the subgaleal space) and volume of the tumescent solution.
• If too much tumescent solution is injected, part of it can be expelled by gentle pressure before planting.
• Prophylactic use of anti-swelling drugs before or in the early postoperative period.
• Maintain a head-elevated position and rest with the back propped up post-surgery.
• Early local ice application to the forehead.

2. Ecchymosis/Bruising

Clinical Manifestations:

Commonly occurs in areas such as the forehead and periorbital region. Appears purplish-blue in the early stage, and may turn yellowish (hemosiderin deposition) during absorption later.

Timing of Occurrence:

Usually occurs 1-2 days after the onset of edema.

Etiology:

Surgical trauma leading to subcutaneous blood vessel damage and bleeding.

Treatment:

• Cold compresses in the early stage (within 24-48 hours) to reduce bleeding.
• Warm compresses may be considered later (after 48 hours) to promote blood circulation and bruise absorption.

Prevention:

• Gentle intraoperative manipulation to reduce unnecessary tissue damage.
• Prompt ice application in the early postoperative period to constrict blood vessels and reduce exudation.

3. Postoperative Bleeding

Clinical Manifestations:

Minor oozing or active bleeding in the recipient or donor area. Low incidence.

Etiology:

• Mismatch between the size of the recipient slit and the follicular unit (e.g., using a 1.2mm or 1.5mm needle to create slits for single fine hairs).
• Abnormal coagulation function in the patient.
• Improper postoperative care, such as accidental scratching or bumping leading to dislodgement of implanted follicles (mostly occurs within 4 days post-surgery; after 4 days, follicles are relatively stable and less prone to bleeding if dislodged).

Treatment:

Apply gentle local pressure with sterile gauze to the bleeding point to achieve hemostasis.

Prevention:

• Select appropriate slit-making instruments based on the size of the follicular units.
• Assess the patient’s coagulation function before surgery.
• Strengthen postoperative care education to avoid scratching and bumping the recipient area.

4. Infection

Clinical Manifestations:

Although rare, vigilance is required. Manifests as local redness, swelling, heat, pain, and possible purulent discharge. (The lecturer encountered an acute infection case (Staphylococcus aureus) 48 hours post-surgery).

Etiology:

• Non-standard disinfection.
• Non-strict aseptic technique.
• Presence of potential local infection foci in the patient (e.g., folliculitis).
• Poor blood sugar control, low immunity, etc., in the patient.

Treatment:

• Strengthen local wound dressing changes (1-2 times daily), keeping the wound clean and dry.
• If pus is present, drain it promptly.
• Local or systemic administration of antibiotics (empirical or selected based on sensitivity results).
• Perform bacterial culture and sensitivity testing if necessary to guide precise medication.

Prevention:

• Strictly adhere to aseptic principles and disinfection standards.
• Address potential infection foci before surgery.
• Control the patient’s blood sugar, assess and improve immune status.

5. Graft Dislodgement

Clinical Manifestations:

Implanted follicular units are dislodged due to external forces (e.g., scratching, bumping).

Treatment:

• If a dislodged graft is found in the early stage (e.g., within 48 hours), is well-preserved, and discovered promptly, re-implantation can be attempted.
• Later (e.g., after 4 days), follicles have begun to establish blood supply and are not easily dislodged; even if dislodged, the survival rate of re-implantation is low.

Prevention:

Strengthen postoperative care education to avoid scratching and bumping the recipient area.

6. Pain

Clinical Manifestations:

Almost all patients experience pain to varying degrees, which is a subjective sensation. Most experience mild pain that can last for 24-72 hours. The proportion of severe pain requiring medication is low.

Etiology:

• Surgical trauma: Excessive extraction density, too deep extraction, oversized extraction cannula diameter, etc.
• Individual differences in pain sensitivity.
• (Note: Persistent pain several months post-surgery is a late complication with different causes).

Treatment:

• Local massage.
• Oral analgesics.

Prevention:

• For patients with thin scalps, appropriately reduce extraction density and depth.
• Select extraction cannulas that match the follicular units.
• Gentle operation to reduce tissue damage.

7. Scalp Itching

Clinical Manifestations:

Itching sensation on the scalp post-surgery, especially in the recipient area.

Etiology:

Normal reaction during the wound healing process, irritation from blood scabs, etc.

Treatment:

• Timely and correct scalp washing as prescribed post-surgery (the lecturer suggests gentle washing can begin 24 hours post-surgery).

Prevention:

Keep the scalp clean and wash on schedule.

VI. Mid-to-Late-Term Postoperative Complications (After 7 Days Post-Surgery)

1. Necrosis

Clinical Manifestations:

Local tissue turns black and loses vitality.

Etiology:

• Excessive tension in the FUT incision, leading to surrounding tissue ischemia and necrosis.
• Scar tissue as the recipient area; if planting density is too high or the transplanted volume is excessive, it may exceed local blood supply capacity, causing circulatory disorders and necrosis.
• Uncontrolled infection, where inflammation damages tissue blood supply.
• Inherently high planting density, exceeding local nutritional supply capacity.

Treatment:

Symptomatic treatment. Strengthen wound dressing changes, keep the wound clean, and use local or systemic antibiotics to prevent and control infection.

Prevention:

• FUT technique: Assess scalp mobility before surgery (suggested incision width not exceeding 2cm) to avoid excessive incision tension.
• Assess the blood supply of the recipient area (especially scar tissue); for atrophic scars, planting density should not be too high.
• Strictly prevent and promptly control infection.
• Reasonably control planting density.

2. Folliculitis

Clinical Manifestations:

One of the most common complications. Often occurs in the donor area of FUE, manifesting as multiple local papules, pustules, possibly with redness, swelling, pain, and can recur.

Timing of Occurrence:

Usually appears 1-2 weeks post-surgery, but can also occur later (may last 2 weeks to 3 months, or even longer).

Etiology:

• Non-strict local disinfection (e.g., Staphylococcus aureus infection).
• Follicle transection/remnants: Partial follicle transection during FUE operation, with remnants left in the skin, causing foreign body irritation.
• Planting too deep: Obstructed follicle growth.
• Incorrect planting: Such as repetitive planting in an existing follicle site, or pressing a follicle too deep under the skin, forming an inclusion.
• Dietary irritation: Ingestion of spicy and irritating foods in the short term post-surgery (e.g., 2 weeks to 1 month) can trigger it.
• Excessive single extraction volume or high extraction density (specific mechanism unclear).

Treatment:

Symptomatic treatment.

• Local alcohol disinfection.
• Topical antibiotic ointment.
• Mature pustules can be lanced and drained under sterile conditions, followed by disinfection and application of ointment.

Prevention:

• Strictly adhere to aseptic principles, strengthen local disinfection.
• Prophylactic use of topical antibiotic drugs.
• Clean blood scabs early (blood scabs are a good culture medium for bacteria).
• Improve operational skills to reduce follicle transection rate.
• Master appropriate planting depth.
• Avoid spicy and irritating foods within 1 month post-surgery, or try a small amount tentatively and observe the reaction.
• Appropriately reduce single extraction volume and extraction density.

3. Recipient Site Erythema

Clinical Manifestations:

Persistent redness in the recipient area, possibly lasting for several months, affecting aesthetics.

Etiology:

Specific mechanism is unclear.

Treatment:

Currently, there is no specific and safe treatment method.

• Ultraviolet irradiation has been suggested (效果不理想 – effect not ideal).
• Laser for redness reduction (concern about damaging transplanted follicles, not used by the lecturer).

Prevention:

No definitive effective prevention method. Postoperative prophylactic use of certain drugs may reduce the incidence but cannot completely eliminate it.

4. Sensory Abnormalities

Clinical Manifestations:

Numbness, paresthesia, or hypersensitivity (pain sensitivity) in the donor or recipient area. Although rare, it can cause long-term distress to the patient if it occurs. More common in large-area scalp transplants (e.g., hairline, forehead), less common in eyebrow and beard transplant areas.

Etiology:

Damage to superficial cutaneous nerves during surgical operation.

Treatment:

• Consult a neurologist; drugs promoting nerve regeneration (e.g., mecobalamin) can be tried.
• Local massage.
• Avoid irritation: Such as using soft pillows, avoiding pressure.
• Most cases recover over time, but the process can be lengthy.

Prevention:

Gentle operation to minimize nerve damage.

5. Secondary Hair Loss/Telogen Effluvium/Shock Loss

Clinical Manifestations:

Appearance similar to alopecia areata. Can occur at the incision margin after FUT, and in the donor or recipient area after FUE.

Timing of Occurrence:

Starts to appear 2-3 weeks post-surgery.

Etiology:

• FUT: Excessive incision tension, causing local ischemia and hypoxia.
• FUE: Excessive extraction density, damaging the subcutaneous vascular network, leading to local ischemia and hypoxia; or it may occur even with normal density (specific reason unknown).

Treatment:

• Topical minoxidil (e.g., Rogaine) can be tried to shorten the course.
• Most cases recover spontaneously.

Prevention:

• FUT: Reduce incision tension, protect the subcutaneous vascular network during operation.
• FUE: Appropriately reduce extraction density (though not absolutely effective).

6. Scarring

Clinical Manifestations:

All hair transplant surgeries leave scars.

• FUT: Linear scar in the donor area.
• FUE: Punctate scars in the donor area, appearing “moth-eaten” or as hypopigmented spots when hair is shaved. The white punctate scars of FUE are due to the removal of black follicular dots originally uniformly distributed on the flesh-colored scalp; even without surgery, if these follicles are lost in other ways, a similar appearance would result. Scars in secondary extraction areas are more prominent.

Etiology:

The inevitable healing process of surgical trauma.

Treatment:

• FUT linear scar: Further hair can be transplanted into the scar.
• FUE punctate scars: SMP (Scalp Micropigmentation) can be considered.

Prevention:

• FUT: Minimize incision tension as much as possible.
• FUE: Use small-diameter extraction needles as much as possible.
• (Some views suggest attempting partial extraction of follicles within a follicular unit to preserve some follicle regeneration and reduce scar appearance, but this is technically difficult and may increase follicle damage rate).

7. Low Survival Rate

Clinical Manifestations:

• Large-scale easy shedding of transplanted hair within 1-2 weeks post-surgery (normally, follicles are relatively stable after 5 days and not easily dislodged; they enter the telogen phase around 3 weeks).
• Sparse hair growth in the transplanted area 1-3 months (or longer) post-surgery, not achieving the expected effect.

Etiology:

• Excessive follicle damage: Such as improper handling during extraction, separation, preservation, or excessively long follicle out-of-body time, poor preservation solution, leading to premature entry into the telogen phase or direct inactivation.
• Poor recipient site blood supply: “Infertile soil,” insufficient to support the survival of transplanted follicles.
• Untreated allergy to minoxidil or other drugs: The lecturer encountered two cases where patients developed local allergy (redness, blisters) after using minoxidil, did not stop the medication, and continued use led to local inflammatory cell infiltration, destroying transplanted follicles, resulting in no hair growth in that area.

Treatment:

If confirmed as a survival rate issue, re-transplantation repair can be considered.

Prevention:

• Foster follicle protection awareness, perform delicate operations, and reduce follicle damage.
• For recipient areas with poor blood supply (e.g., scar tissue), appropriately reduce planting density, or consider improving local blood supply through methods like fat grafting before surgery.
• Closely monitor adverse drug reactions in patients; if allergy to minoxidil or other drugs occurs, stop the medication promptly and treat symptomatically.

8. Poor Aesthetic Outcome/Unnatural Appearance

Clinical Manifestations:

Unnatural arrangement, direction, density, and transition of hair in the transplanted area, lacking aesthetic appeal. Such as a stiff hairline, messy direction, or eyebrow transplant appearing like “weeds.”

Etiology:

• Lack of aesthetic consideration in preoperative design.
• The operator has not mastered the aesthetic principles of natural hair growth (e.g., direction, angle, density gradient).
• Unskilled operational technique.

Treatment:

• For small and exposed areas like eyebrows and eyelashes, consider removing poorly performing follicles and re-transplanting.
• For hair, secondary hair transplantation can be used for modification and densification.
• Eyelash repair: Electrolysis is not recommended (due to the soft tarsal plate, difficulty in positioning after anesthesia, and a tendency for repeated operations to form scars); it is advisable to incise the lid margin and remove follicles one by one under a magnifying glass, which is less traumatic and allows for quick recovery.

Prevention:

• Conduct thorough aesthetic design before surgery, adhering to the natural characteristics of hair growth.
• Strictly follow the designed direction, angle, and density during planting.
• Continuously improve aesthetic literacy and operational skills.

9. Hair Curling/Kinking

Clinical Manifestations:

The growth direction of transplanted hair is normal, but the hair shaft appears curled or not straight. Often becomes apparent during new hair growth (e.g., after 6 months), may not be obvious in the early stage.

Etiology:

• The patient’s own hair texture is inherently curly. Transplantation cannot change the inherent characteristics of the follicle.
• The follicle bulb was not fully placed at the bottom of the recipient slit during implantation, or it was folded or squeezed. This may be related to insufficient tumescent anesthesia or improper planting technique (e.g., slits made too shallow, or the channel becoming shallower after tumescent fluid absorption, while the follicular unit is relatively long, leading to squeezing during implantation).

Treatment:

• Small areas like eyebrows: Removal can be considered.
• Hair: Wait for natural improvement; some cases may improve after 1-2 hair growth cycles (about 2-3 years).

Prevention:

• Moderate tumescent anesthesia: Ensure recipient slits have sufficient depth to accommodate follicular units. Avoid excessive tumescent fluid injection, which might make slits appear deep enough intraoperatively but actually become shallower after compression.
• Appropriate slit depth (e.g., 4-5mm) to provide adequate space for follicles.
• Appropriate planting depth to avoid follicle compression within the slit.
• Slit diameter matching the size of the follicular unit, avoiding the use of overly fine slits for larger follicular units, which can lead to forceful insertion and damage.

10. Transient Leukotrichia

Clinical Manifestations:

Temporary white hair appearing in the donor area or native hair area. Relatively rare.

Etiology:

Specific mechanism unknown. The relationship with factors like freezing or hydrogen peroxide is speculative and lacks evidence.

Treatment:

No special treatment needed; it is a transient phenomenon, and the white hair will revert to its original color over time.

Prevention:

Cause unknown, hence no effective prevention method.

11. Uneven Recipient Area Surface

Clinical Manifestations:

Uneven skin surface in the recipient area. Currently less common.

Etiology:

May be related to planting technique, postoperative care, etc.

12. Recurrent Infection

Clinical Manifestations:

2-4 months post-surgery, recurrent infection symptoms appear locally, even if there was no initial infection.

Etiology:

Specific mechanism unknown.

Treatment:

Local application of antibiotic drugs.

Prevention:

Cause unknown, difficult to prevent specifically.

13. Arteriovenous Fistula

Clinical Manifestations:

Very rare, more common in the temporal region.

Etiology:

Simultaneous damage to an artery and an adjacent vein during surgery, leading to the formation of an abnormal channel between them, causing blood to flow directly from the artery to the vein without passing through the capillary network.

Treatment:

• Vascular embolization (high risk, embolic agent may enter systemic circulation).
• Surgical ligation: Locate the fistula, make a local incision, and ligate the abnormally communicating vessels (more direct and effective).

Prevention:

Pay attention to anatomical layers during operation to avoid deep vascular damage.

VII. Non-Complications Requiring Attention

1. Intraoperative Oozing

Description:

Normal minor oozing during surgery, not a complication. However, if persistent or copious, it needs attention.

Causes:

Prolonged surgery time; patient’s coagulation function issues.

Management/Prevention:

Ensure normal coagulation function in the patient; if surgery time is long, tumescent fluid can be injected in stages; local gauze compression.

2. Hair Shedding Phase/Telogen Effluvium

Description:

Normal physiological cycle change experienced by transplanted follicles. Usually starts 3-4 weeks post-surgery, where the transplanted hair shafts shed, follicles enter the telogen phase, and then new hair regrows around 4-9 months post-surgery. This needs to be fully explained to the patient to alleviate concerns.

3. Progressive Native Hair Loss

Description:

The patient’s pre-existing androgenetic alopecia or other issues continue to progress post-surgery, leading to continued thinning of hair in unplanted areas.

Management:

Continue regular medication (e.g., minoxidil, finasteride) post-surgery to treat native hair loss; re-transplantation may be necessary.

4. Low Planting Density (Not Due to Survival Issues)

Description:

Overall low density post-surgery, not caused by poor follicle survival rate, but due to an insufficient number of follicles planted according to the surgical plan, or inherently sparse slit density.

Emphasis:

This is an issue related to surgical planning or execution, not a complication.