Tissue Healing in Hemicraniectomy

Abstract

Introduction Decompressive hemicraniectomy (DHC) is a last-resort treatment for refractory intracranial hypertension. Perioperative morbidity is associated with high risks of wound healing disturbances (WHD). Recently, a retromastoidal frontoparietooccipital (RMF) incision type was performed to avoid healing disturbance due to enhanced tissue flap perfusion compared to the classical reverse "question mark" ("Dandy flap") incision. The goal of this study was to analyze the details of tissue healing problems in DHC. Materials and methods A total of 60 patients who underwent DHC were retrospectively analyzed. In 30 patients the "Dandy flap" incision (group A) and in 30 patients the RMF incision (group B) was made. Since no evidence-based data for the incision type that favors better wound healing exists, the form of incision was left at the surgeon´s discretion. Documentation of the patients was screened for the incidence of WHD: wound necrosis, dehiscence, and cerebrospinal fluid (CSF) leakage. Patient age, the time interval from surgery until the appearance of WHD, the length of surgeries in minutes, and the indications of the DHC were analyzed. A Chi-square test of independence was performed to examine the relationship between the incision type and the appearance of WHD with the statistical significance level set at p<0.05. The mean age of the patients, the mean time interval from surgery until the occurrence of WHD, and the mean length of the surgery between the two groups were compared using an independent sample t-test with the statistical significance level set at p<0.05. Results The most common indication for DHC in both groups was malignant MCA infarction (n=20, 66.6% for group A and n=16, 53.3% for group B). CSF leakage was 20% of the most frequent WHD in each group. Wound necrosis was observed only in group A. Although group B showed 13.3% fewer WHD than group A, this difference was not statistically significant. There was no statistically significant difference in the time range between surgery and the occurrence of WHD between the two groups. The length of surgery in group B was significantly shorter than in group A (120.2 mins vs. 103.7 mins). Conclusion A noticeable trend for reduced WHD was observed in the patient group using the RMF incision type although the difference was not statistically significant. We praise that the RMF incision allows an optimized skin-flap vascularization and, thereby, facilitates better wound healing. We were able to show a statistically shorter length of surgery with the RMF incision in contrast to the classic "Dandy flap" incision. Larger multicenter studies should be implemented to analyze and address the major advantages and pitfalls of the routinely applied incision techniques.

Keywords: dandyflap; emergency neurosurgery; hemicraniectomy; retromastoidal (rmf) incision; tissue healing.

Figure 1. The reverse “question mark” or “Dandy flap” incision

The reverse “question mark” (“Dandy flap”) incision is superimposed on the vasculature of the lateral scalp. The STA provides the main arterial blood supply of the skin flap created and is prone to injury in the emergency operating setting of a hemicraniectomy. References [7,8] STA: superficial temporal artery, PAA: posterior auricular artery, OA: occipital artery, blue line: incision.

Figure 2. RMF incision

With the retromastoidal frontoparietooccipital (RMF) incision, not only the STA but the PAA is also providing arterial supply to the skin flap created. The STA being the main arterial supply of the skin flap is protected with this type of incision. Care must also be taken to preserve the OA. References [7,9,10] STA: superficial temporal artery, PAA: posterior auricular artery, OA: occipital artery, blue line: incision.