Comparison of minimally invasive versus conventional open harvesting technique for iliac bone graft in secondary alveolar bone grafting in cleft palate patients: a systematic review

Iliac Crest Bone Graft Harvest for Alveolar Cleft Repair: A Systematic Review Comparing Minimally Invasive Trephine and Conventional Open Techniques

Background: In the course of developing a standardized pathway for alveolar cleft repair, we conducted a systematic review comparing minimally invasive trephine with conventional open technique for iliac crest bone graft harvest in a pediatric population. Methods: A systematic review was conducted of studies comparing open with minimally invasive trephine techniques in pediatric populations undergoing alveolar cleft repair. Exclusion criteria included reviews, case series, editorials, abstracts, and those with adult-only populations. Data were compiled with outcome variables selected a priori. Results: Of 422 manuscripts screened, five met criteria. These comprised 257 patients (116 open, 141 trephine). Average age was 11 years. Patients undergoing trephine harvest had reduced length of stay (1.0-5.0 days trephine vs 1.25-5.4 days open), time to unassisted ambulation (16-46 hours vs 20-67 hours open), and less postoperative narcotic use (0.31 mg/kg vs 1.64 mg/kg IV morphine). Volume of cancellous bone was reported as 2.53 mL for open versus 1.22 mL for trephine in one study, and trephine graft was supplemented with demineralized bone in 54% of cases in another study. The use of anesthetic adjuncts was inconsistent but had a significant effect on postoperative pain and ambulation. Conclusions: Compared to open techniques, the minimally invasive trephine bone graft harvest is associated with a shorter time to discharge, slightly lower infection rates, and reduced opioid use. The possible benefits of trephine harvest must however be balanced against the risk of insufficient graft harvest. Finally, the choice of perioperative analgesic adjuncts significantly impacts patient outcomes regardless of the technique employed.

Differences in Practice in Alveolar Bone Grafting Among American Cleft Palate-Craniofacial Association Members

The purpose of this study is to determine areas of agreement and disagreement among American Cleft Palate-Craniofacial Association (ACPA)members in the clinical practice of alveolar bone grafting (ABG), to guide further research to optimize ABG practices.

A cross-sectional survey was conducted.

The respondents were in an academic, combination, or private practice.

The respondents were either plastic or oral and maxillofacial surgeons (OMFS) from various countries.

A de-identified 24-question online survey was distributed to ACPA surgeon members utilizing the Research Electronic Data Capture (REDCap) tool.

Data collected included surgeon specialty, use of various alveolar bone graft surgical techniques, as well as protocols.

There was more variability than consensus between specialties with regards to the preoperative workup, timing of surgery, materials used for bone graft, surgical techniques, perioperative management, and postoperative evaluation. There was consensus on grafting during mixed dentition, not staging soft and hard tissue closure, and using iliac crest for primary and secondary grafting. Disagreements involved factors used to time the procedure and type of imaging used to assess viability. Technical differences involved incision type, part of bone grafted, use of minimally invasive technique, and material used for revisions.

Aside from areas of consensus among surgeons on ABG, several areas, including use of bone substitutes in revision grafting, incision and type of iliac crest graft used during initial grafting, and postoperative protocols, had no consensus. These areas should be targets of further research to determine if there truly is an optimal method to perform ABG.

The study was approved by the University of Illinois at Chicago Institutional Review Board. A de-identified 24-question online survey was distributed to surgeon members of the ACPA utilizing the REDCap tool on August 7, 2020. The survey questions consisted of multiple choice and multiple selection questions including an option to select "other" and specify the information in a blank space. Data collected included surgeon specialty, use of various alveolar bone graft surgical techniques, as well as pre and postoperative protocols. The full survey is included in online Supplemental material. Data analysis was performed in SPSS Statistics 27 (IBM Corp.). Descriptive statistics were performed, and chi-square was used to test for significant differences in survey responses between groups.

The strategy of composite grafting with BMP2-Loaded calcium phosphate cements and autogenous bone for alveolar cleft reconstruction

Purpose: To remedy the drawbacks of traditional autogenous bone harvesting in alveolar bone grafting (ABG), a novel strategy of composite grafting with BMP2-loaded calcium phosphate cements (BMP2-CPC) and autogenous bone harvested by minimally invasive technique was developed and evaluated for its bone-repairing efficacy.

Materials and methods: A chart review was conducted for 19 patients with unilateral alveolar clefts who underwent secondary ABG from 2017 to 2020. Of the enrolled patients, 9 patients underwent grafting with autogenous bone harvested by traditional trap door technique (group I), and 10 patients underwent grafting with the composite graft comprising BMP2-CPC and autogenous bone harvested by minimally invasive technique at a ratio of 1:1 by volume (group II). The clinical performance of the composite graft was comprehensively evaluated in terms of clinical, radiographic and histological perspectives.

Results: The present results demonstrated that the composite graft exhibited satisfactory bone-repairing efficacy comparable to that of the autogenous bone graft on the premise of lower amount of harvested bone. The post-surgical resorption of bone volume and vertical height of grafted area was significantly slower in group II. The favourable resorption performance of BMP2-CPC contributed to preserving the post-surgical bony contour reconstructed with the composite graft.

Conclusion: The composite graft comprising BMP2-CPC and autogenous bone harvested by minimally invasive technique was demonstrated to be an eligible alternative for application in ABG, especially for its improved resorption performance in preserving post-surgical bony contour.

"Improved Success Rate with Corticocancellous Block Compared to Cancellous-only Trephine Technique in Alveolar Bone Grafting from the Iliac Crest"

BACKGROUND

Alveolar bone grafting is an important component of cleft lip and palate treatment, with iliac crest as the most common donor site. Although studies have attempted to quantify alveolar bone graft resorption, few have directly compared the outcomes of graft techniques. This study compared the long-term success rates of corticocancellous block to trephine cancellous-only alveolar bone grafting from the iliac crest.

METHODS

A retrospective review of all cleft lip and palate patients undergoing alveolar bone grafting over 14 years was performed. Power analysis was performed to determine sample size. Data including patient demographics, surgical technique, need for repeat grafting, complications, length of hospitalization, and follow-up were collected. Statistical analyses of outcomes were performed based on initial graft technique.

RESULTS

A total of 106 initial operations met criteria, with 73 using trephine technique, 30 utilizing corticocancellous block, and 3 undergoing open cancellous harvest. The overall regraft rate was 40% with an average follow-up of 43.5 months. Patients with corticocancellous block grafting had significantly lower rates of repeat grafting compared to trephine technique (16.7% vs. 47.9%, p<0.001). There was no significant difference in complications rates or length of admission between treatment groups.

CONCLUSIONS

The use of corticocancellous block alveolar bone grafting demonstrated significantly higher success rates when compared to cancellous-only trephine techniques with no difference in complication rates. Although this must be weighed against the minor disadvantages of open iliac harvest, surgeons should consider incorporating en bloc corticocancellous bone to optimize outcomes in alveolar bone grafting.

Bone regeneration of induced pluripotent stem cells derived from peripheral blood cells in collagen sponge scaffolds

Stem cell-based regeneration therapy offers new therapeutic options for patients with bone defects because of significant advances in stem cell research. Although bone marrow mesenchymal stem cells are the ideal material for bone regeneration therapy using stem cell, they are difficult to obtain. Induced pluripotent stem cells (iPSCs) are now considered an attractive tool in bone tissue engineering. Recently, the efficiency of establishing iPSCs has been improved by the use of the Sendai virus vector, and it has become easier to establish iPSCs from several type of somatic cells. In our previous study, we reported a method to purify osteogenic cells from iPSCs.

Adapting the Pore Size of Individual, 3D-Printed CPC Scaffolds in Maxillofacial Surgery

Three dimensional (3D) printing allows additive manufacturing of patient specific scaffolds with varying pore size and geometry. Such porous scaffolds, made of 3D-printable bone-like calcium phosphate cement (CPC), are suitable for bone augmentation due to their benefit for osteogenesis. Their pores allow blood-, bone- and stem cells to migrate, colonize and finally integrate into the adjacent tissue. Furthermore, the pore size affects the scaffold’s stability. Since scaffolds in maxillofacial surgery have to withstand high forces within the jaw, adequate mechanical properties are of high clinical importance. Although many studies have investigated CPC for bone augmentation, the ideal porosity for specific indications has not been defined yet. We investigated 3D printed CPC cubes with increasing pore sizes and different printing orientations regarding cell migration and mechanical properties in comparison to commercially available bone substitutes. Furthermore, by investigating clinical cases, the scaffolds’ designs were adapted to resemble the in vivo conditions as accurately as possible. Our findings suggest that the pore size of CPC scaffolds for bone augmentation in maxillofacial surgery necessarily needs to be adapted to the surgical site. Scaffolds for sites that are not exposed to high forces, such as the sinus floor, should be printed with a pore size of 750 µm to benefit from enhanced cell infiltration. In contrast, for areas exposed to high pressures, such as the lateral mandible, scaffolds should be manufactured with a pore size of 490 µm to guarantee adequate cell migration and in order to withstand the high forces during the chewing process.

Endoscope-Assisted Multilayered Repair in Oronasal Fistula

Oronasal fistula following cleft palate repair is a considerable complication with a recurrence rate of 33% to 37% and remains a challenging problem for surgeons. Furthermore, many patients have undergone several operations and experienced scar problems and other forms of morbidity. Therefore, we report a multilayered technique for oronasal fistula closure using an endoscopic nasal inferior turbinate composite graft with a palatal advance flap. This will increase the success rate after closure of small-sized oronasal fistula surgery without complications or recurrence (IRB: 2020-1671-0001).