Hypertension and Head and Neck Free Tissue Transfer

Results from a recently published study help clarify the clinical implications of hypertension in regard to post-operative outcomes following head and neck free tissue transfer. Some prior studies indicated hypertension to be associated with unplanned reoperation and cardiac complications in free tissue transfer, while other studies did not indicate the association. In order to clarify this relationship, the present study used a nationwide sample to evaluate the clinical implications of hypertension requiring medication on outcomes in head and neck free tissue transfer. The research appeared in Head & Neck.

Due in part to both its versatility and its effectiveness, microvascular free tissue transfer has become the preferred choice for many head and neck surgeons. However, the procedure requires close monitoring post-operatively, and there is a relatively high number of post-operative complications associated with the procedure. The typical head and neck oncologic patient also has a relatively high number of comorbidities as well, which suggests that head and neck surgeons may be able to improve pre-operative planning to reduce the risk factors for complications and reoperation for reconstructive patients.

“We believed that having a better understanding of how hypertension impacts head and neck reconstructive patients could lead to improved care for a large number of patients,” explains Patrick Byrne, MD, MBA, the chairman of Cleveland Clinic’s Head & Neck Institute and one of the study’s authors. “Both patients and head and neck surgeons could benefit in the pre-operative planning and post-operative care stages from knowing the most common complications in microvascular reconstructive patients with hypertension.”

Study design

For the study, 3,406 head and neck free flap cases were retrospectively analyzed. Of these cases, 1,808 (53.1%) patients did not have a history of hypertension, and 1598 (46.9%) patients had hypertension requiring medication. The patients with hypertension had an average BMI ≥ 30 (26.7% vs 17.5%, p < 0.001), were American Society of Anesthesiologists (ASA) Class 3 (77.2% vs. 65.5%, p < 0.001), had diabetes (20.1% vs. 5.2%, p < 0.001), and had chronic obstructive pulmonary disease (COPD) (8.8% vs. 5.1%, p < 0.001).

Findings

Through multivariable analysis, the research group found that hypertension in head and neck microvascular free tissue transfer patients was associated with obesity (OR [odds ratio] = 2.04 [95% CI 1.66, 2.50], p < 0.001), diabetes (OR = 3.25 [95% CI 2.52, 4.22], p < 0.001), ASA Class 3 (OR = 1.71 [95% CI 1.40–2.09], p < 0.001) or 4 (OR = 2.07 [95% CI 1.49–2.88], p < 0.001), and age > 75 (OR = 40.53 [95% CI 18.79, 106.04], p < 0.001).

The research group also found that having hypertension that required medication significantly increased post-operative stay (mean days ± SD; 10.98 ± 7.70 vs. 10.04 ± 7.07, p < 0.001). However, the total operation time was unaffected (mean minutes ± SD; 528.09 ± 155.64 vs. 520.30 ± 160.56, p = 0.152). Although death rates and readmission rates were insignificant between the cohorts, the rate of any complication was following free flap surgery among patients with hypertension (47.6% vs. 39.8%, p < 0.0001). Surgical complications were also more common among patients with hypertension (40.3% vs. 35.2%, p = 0.003), but the authors note that this rate was primarily related to an increased intra/post-operative transfusion rate (30.6% vs. 25.1%, p < 0.001).

Multivariable models showed that hypertension in free flap patients was associated with any post-operative complication (OR = 1.27 [95% CI 1.09–1.48], p = 0.002), surgical complications (OR = 1.17 [95% CI 1.00, 1.37], p = 0.047) and medication complications (OR = 1.53 [95% CI 1.24, 1.90], p < 0.001).

“In our study, medical and surgical complications were significantly more prevalent in hypertensive patients on multivariable analysis” says Eric Lamarre, MD, a head and neck surgeon in Cleveland Clinic’s Head & Neck Institute and one of the authors of the study. “We found that the most frequent, statistically significant complications in hypertensive free flap patients were intra/post-operative transfusion, pneumonia and ventilator dependence after 48 hours when compared to patients without hypertension. Patients with hypertension are at a higher risk for returning to the operating room after head and neck free tissue transfer, so hypertension may be a high-yield target for quality improvement programs.”