How I do it-the posterior question mark incision for decompressive hemicraniectomy

A Comparison of Decompression Size and Craniectomy Speed of Reverse Question Mark Versus Retroauricular Incisions for Decompressive Hemicraniectomy: A Cadaver Study

BACKGROUND AND OBJECTIVES

Decompressive hemicraniectomy is a common emergent surgery for patients with stroke, hemorrhage, or trauma. The typical incision is a reverse question mark (RQM); however, a retroauricular (RA) incision has been proposed as an alternative. The widespread adoption ofthe RA incision has been slowed by lack of familiarity and concerns over decompression efficacy. Our goal is to compare the RA vs RQM incisions regarding decompression safety and to examine skill acquisition among resident neurosurgeons.

METHODS

Six cadaveric heads were randomized to first receive either RQM or RA decompressive hemicraniectomy, which was followed by use of the other incision on the contralateral side. Primary endpoints were decompression circumference and time to bone flap removal. Resident neurosurgeon (postgraduate year 3 through 7) confidence and operative times were compared.

RESULTS

All craniectomies yielded decompression diameters >13 cm (RQM: 13.5-15.5 cm; RA: 13.0-16.5 cm) and residual temporal bone heights <1.5 cm (RQM: 0.5-1.3 cm; RA: 0.5-1.5 cm). There were no differences between the RA and RQM groups in decompression circumference (P = .6605), residual temporal bone height (P = .7121), or time from incision until bone flap removal (P = .8452). There was a nonsignificant trend toward a shorter incision length with RA (RQM: 37.7 ± 0.7 cm vs RA: 35.1 ± 0.9; P = .0729). Regardless of which incision was performed first, operative time significantly improved from the first craniectomy to the second (-174.6 seconds, P = .0186). Surgeon confidence improved more with the RA incision, and there was a linear association with experience and time to bone flap removal in the RQM (P = .04) but not the RA (P = .95) groups.

CONCLUSION

The RA incision may provide adequate operative exposure without significant changes in operative time. Cadaveric labs improve skill acquisition and should be considered during implementation of novel surgical approaches into practice.

Decompressive craniectomy incisions: all roads lead to bone

INTRODUCTION

Decompressive craniectomy and craniotomy are among the most common procedures in Neurosurgery. In recent years, increased attention has focused on the relationships between incision type, extent of decompression, vascular supply to the scalp, cosmetic outcomes, and complications. Here, we review the current literature on scalp incisions for large unilateral front-temporo-parietal craniotomies and craniectomies.

METHODS

Publications in the past 50 years on scalp incisions used for front-temporo-parietal craniectomies/craniotomies were reviewed. Only full texts were considered in the final analysis. A total of 27 studies that met the criteria were considered for the final manuscript. PRISMA guidelines were adopted for this study.

RESULTS

Five main incision types have been described. In addition to the question mark incision, other common incisions include the T-Kempe, developed to obtain wide access to the skull, the retroauricular incision, designed to spare the occipital branch, as well as the N-shaped and cloverleaf incisions which integrate with pterional approaches. Advantages and drawbacks, integration with existing incisions, relationships with the main arteries, cosmetic outcomes, and risks of wound complications including dehiscence, necrosis, and infection were assessed.

DISCUSSION

The reverse-question mark incision, despite being a mainstay of trauma neurosurgery, can place the vascular supply to the scalp at risk and favor wound dehiscence and infection. Several incisions, such as the T-Kempe, retroauricular, N-shaped, and cloverleaf approaches have been developed to preserve the main vessels supplying the scalp. Incision choice needs to be carefully weighted based on the patient's anatomy, position and size of main vessels, risk of wound dehiscence, and desired volume of decompression.

Biomaterials for Regenerative Cranioplasty: Current State of Clinical Application and Future Challenges

Acquired cranial defects are a prevalent condition in neurosurgery and call for cranioplasty, where the missing or defective cranium is replaced by an implant. Nevertheless, the biomaterials in current clinical applications are hardly exempt from long-term safety and comfort concerns. An appealing solution is regenerative cranioplasty, where biomaterials with/without cells and bioactive molecules are applied to induce the regeneration of the cranium and ultimately repair the cranial defects. This review examines the current state of research, development, and translational application of regenerative cranioplasty biomaterials and discusses the efforts required in future research. The first section briefly introduced the regenerative capacity of the cranium, including the spontaneous bone regeneration bioactivities and the presence of pluripotent skeletal stem cells in the cranial suture. Then, three major types of biomaterials for regenerative cranioplasty, namely the calcium phosphate/titanium (CaP/Ti) composites, mineralised collagen, and 3D-printed polycaprolactone (PCL) composites, are reviewed for their composition, material properties, and findings from clinical trials. The third part discusses perspectives on future research and development of regenerative cranioplasty biomaterials, with a considerable portion based on issues identified in clinical trials. This review aims to facilitate the development of biomaterials that ultimately contribute to a safer and more effective healing of cranial defects.

Novel hemicraniectomy: Preserving temporal structures in severe traumatic brain injury patients

OBJECTIVE

This study evaluates the efficacy and safety of Novel Hemicraniectomy Technique (NHT) in Severe Traumatic Brain Injury (STBI) patients.

METHODS

A retrospective analysis of 79 STBI patients who underwent decompressive hemicraniectomy was conducted. The study compared 25 patients treated with NHT and 54 patients treated with Classic Decompressive Craniectomy (CDC), focusing on therapeutic effects, complications, intracranial pressure, and prognosis.

RESULTS

NHT resulted in shorter surgery duration (101.4 ± 11.8 min, p = 0.008) and greater decompressive effects (21.4 ± 5.6 mmHg, p = 0.018). It also prevented temporal muscle injury (0.0 %, p = 0.026), superficial temporal artery injury (0.0 %, p = 0.009), and masticatory dysfunction (5.9 %, p = 0.040). However, NHT showed no significant advantages in intracranial pressure normalization time (3.5 ± 0.9 days, p = 0.679), hospital stay length (34.3 ± 10.4 days, p = 0.805), intraoperative blood loss reduction (284.0 ± 82.6 ml, p = 0.190), or Glasgow Outcome Scale (GOS) scores (2.8 ± 0.9, p = 0.814) and prognosis (32.0 %, p = 0.831) compared to CDC.

CONCLUSION

NHT offers shorter surgery duration (101.4 ± 11.8 min vs 107.7 ± 8.2 min), superior decompressive effects (21.4 ± 5.6 mmHg vs 17.7 ± 6.9 mmHg), and better protection of temporal structures, but does not significantly reduce complications or improve prognosis compared to CDC. Prospective studies with larger sample sizes are needed to better understand the potential benefits of NHT in STBI treatment.

Comparison of Retroauricular and Reverse Question Mark Incisions for Decompressive Hemicraniectomy

BACKGROUND

The retroauricular (RA) incision has several theoretical benefits compared with the reverse question mark (RQM) incision for decompressive hemicraniectomy (DHC), but limited data comparing the 2 exist.

METHODS

Consecutive patients who underwent DHC between 2016 and 2022 and survived ≥30 days at a single institution were included. The primary outcome was wound complication within 30 days (30dWC) requiring reoperation. Secondary outcomes included 90-day wound complication (90dWC), craniectomy size in anterior-posterior (AP) and superior-inferior dimensions, distance from the inferior craniectomy margin to the middle cranial fossa (MCF), estimated blood loss (EBL), and operative duration. Multivariate analyses were performed for each outcome.

RESULTS

A total of 110 patients (RA group: 27, RQM group: 83) were included. The incidence of 30dWC was 1.2% and 0 in the RQM and RA groups, respectively. The incidence of 90dWC was 2.4% and 3.7% in the RQM and RA groups, respectively. There was no difference in mean AP size (RQM: 15 cm, RA: 14.4 cm; P = 0.18), superior-inferior size (RQM: 11.8 cm, RA: 11.9 cm; P = 0.92), and distance from MCF (RQM: 15.4 mm, RA: 18 mm; P = 0.18). Mean EBL (RQM: 418 mL, RA: 314 mL; P = 0.36) and operative duration (RQM: 103 min, RA: 89 min; P = 0.14) were similar. There was no difference in cranioplasty wound complications, EBL, or operative duration.

CONCLUSIONS

Wound complications are comparable between the RQM and RA incisions. The RA incision does not compromise craniectomy size or temporal bone removal.

Custom-made 3D printing-based cranioplasty using a silicone mould and PMMA

All types of cranioplasty techniques restore the morphology of the skull and affect patient aesthetics. Safe and easy techniques are required to enhance patients' recovery and the rehabilitation process. We propose a new method of cranioplasty. The 3-dimensional (3D) reconstruction of a thin-layer computed tomography (CT) scan of the skull was used to reflect the intact side onto the defect and subtract the overlapping points from one another. In this way, a 3D model of the planned implant can be built in the required shape and size. The precise fit of the implant can be checked by printing the defective part of the skull in case it can be modified. A sterilisable silicone mould based on the finalized model was created afterwards. Polymethyl methacrylate implants were prepared directly in an aseptic environment in the operating room during surgery. Between 2005 and 2020, we performed 54 cranioplasties on 52 patients whose craniotomies were performed previously for indications of traumatic brain injury, stroke or tumour surgeries. No technical problems were noted during the operations. In 2 cases, septic complications that occurred were not connected to the technique itself, and the implants were removed and later replaced. Our proposed technique based on 3D-printed individual silicone moulds is a reliable, safe, easily reproducible and low-cost method to repair different skull defects.

Craniectomy size and decompression of the temporal base using the altered posterior question-mark incision for decompressive hemicraniectomy

The altered posterior question-mark incision for decompressive hemicraniectomy (DHC) was proposed to reduce the risk of intraoperative injury of the superficial temporal artery (STA) and demonstrated a reduced rate of wound-healing disorders after cranioplasty. However, decompression size during DHC is essential and it remains unclear if the new incision type allows for an equally effective decompression. Therefore, this study evaluated the efficacy of the altered posterior question-mark incision for craniectomy size and decompression of the temporal base and assessed intraoperative complications compared to a modified standard reversed question-mark incision. The authors retrospectively identified 69 patients who underwent DHC from 2019 to 2022. Decompression and preservation of the STA was assessed on postoperative CT scans and CT or MR angiography. Forty-two patients underwent DHC with the standard reversed and 27 patients with the altered posterior question-mark incision. The distance of the margin of the craniectomy to the temporal base was 6.9 mm in the modified standard reversed and 7.2 mm in the altered posterior question-mark group (p = 0.77). There was no difference between the craniectomy sizes of 158.8 mm and 158.2 mm, respectively (p = 0.45), and there was no difference in the rate of accidental opening of the mastoid air cells. In both groups, no transverse/sigmoid sinus was injured. Twenty-four out of 42 patients in the modified standard and 22/27 patients in the altered posterior question-mark group had a postoperative angiography, and the STA was preserved in all cases in both groups. Twelve (29%) and 5 (19%) patients underwent revision due to wound-healing disorders after DHC, respectively (p = 0.34). There was no difference in duration of surgery. Thus, the altered posterior question-mark incision demonstrated technically equivalent and allows for an equally effective craniectomy size and decompression of the temporal base without increasing risks of intraoperative complications. Previously described reduction in wound-healing complications and cranioplasty failures needs to be confirmed in prospective studies to demonstrate the superiority of the altered posterior question-mark incision.

Infection-related failure of autologous versus allogenic cranioplasty after decompressive hemicraniectomy - A systematic review and meta-analysis

Introduction

Cranioplasty is required after decompressive craniectomy (DC) to restore brain protection and cosmetic appearance, as well as to optimize rehabilitation potential from underlying disease. Although the procedure is straightforward, complications either caused by bone flap resorption (BFR) or graft infection (GI), contribute to relevant comorbidity and increasing health care cost. Synthetic calvarial implants (allogenic cranioplasty) are not susceptible to resorption and cumulative failure rates (BFR and GI) tend therefore to be lower in comparison with autologous bone. The aim of this review and meta-analysis is to pool existing evidence of infection-related cranioplasty failure in autologous versus allogenic cranioplasty, when bone resorption is removed from the equation.

Materials and methods

A systematic literature search in PubMed, EMBASE, and ISI Web of Science medical databases was performed on three time points (2018, 2020 and 2022). All clinical studies published between January 2010 and December 2022, in which autologous and allogenic cranioplasty was performed after DC, were considered for inclusion. Studies including non-DC cranioplasty and cranioplasty in children were excluded. The cranioplasty failure rate based on GI in both autologous and allogenic groups was noted. Data were extracted by means of standardized tables and all included studies were subjected to a risk of bias (RoB) assessment using the Newcastle-Ottawa assessment tool.

Results

A total of 411 articles were identified and screened. After duplicate removal, 106 full-texts were analyzed. Eventually, 14 studies fulfilled the defined inclusion criteria including one randomized controlled trial, one prospective and 12 retrospective cohort studies. All but one study were rated as of poor quality based on the RoB analysis, mainly due to lacking disclosure why which material (autologous vs. allogenic) was chosen and how GI was defined. The infection-related cranioplasty failure rate was 6.9% (125/1808) for autologous and 8.3% (63/761) for allogenic implants resulting in an OR 0.81, 95% CI 0.58 to 1.13 (Z ​= ​1.24; p ​= ​0.22).

Conclusion

In respect to infection-related cranioplasty failure, autologous cranioplasty after decompressive craniectomy does not underperform compared to synthetic implants. This result must be interpreted in light of limitations of existing studies. Risk of graft infection does not seem a valid argument to prefer one implant material over the other. Offering an economically superior, biocompatible and perfect fitting cranioplasty implant, autologous cranioplasty can still have a role as the first option in patients with low risk of developing osteolysis or for whom BFR might not be of major concern.

Trial registration

This systematic review was registered in the international prospective register of systematic reviews. PROSPERO: CRD42018081720.

Tissue Healing in Hemicraniectomy

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.