Is immediate bony microsurgical reconstruction after head and neck tumor ablation associated with a higher rate of local recurrence?

Resection status and margin control in intraoperative frozen sectioning analysis of oral squamous cell carcinoma

PURPOSE

Intraoperative frozen section analysis (IFSA) is a well-established procedure for determining the intraoperative soft tissue resection status in patients with oral squamous cell carcinoma (OSCC). Margin status is a major predictor of the patient´s outcome, histologically free margins of ≥ 5 mm are demanded. This study evaluates the accuracy of IFSA, the impact of margin status and the impact of intraoperative margin revision on disease-free survival (DFS) and overall survival (OS).

METHODS

This retrospective study included 213 patients with OSCC. IFSA results were compared with definitive histopathological reports, Kaplan-Meier analysis was performed. Cut-off values were calculated for resection margins considering known risk factors.

RESULTS

IFSA showed positive margins in 8 cases (3.8%). Kaplan-Meier analysis revealed no significant differences for OS or DFS if R0-status was achieved by initial resection or immediate re-resection. Final histopathological evaluation revealed false-positive IFSA in 3/8 cases (37.5%) and false-negative IFSA in 1/205 cases (0.5%). Sensitivity was 83.3% and specificity was 98.6%. Analysis of optimal cut-off values showed no general need for larger resection margins in patients with risk factors. Cut-off values were slightly higher for patients with the risk factor alcohol consumption (7 mm for OS and DFS) or pN + ECS- disease (7 mm for DFS). Optimal cut-off values for tumour-margin-distance were around 6 mm.

CONCLUSION

IFSA provides a valuable assessment method for intraoperative soft tissue resection margins. Risk factors seemingly do not significantly influence the extent of tumour resection.

Assessment of the bony resection margin distance in bone-invasive oral cancer using laser-induced breakdown spectroscopy

OBJECTIVES

Inadequate resection margins of less than 5 mm impair local tumor control. This weak point in oncological safety is exacerbated in bone-infiltrating tumors because rapid bone analysis procedures do not exist. This study aims to assess the bony resection margin status of bone-invasive oral cancer using laser-induced breakdown spectroscopy (LIBS).

MATERIALS AND METHODS

LIBS experiments were performed on natively lasered, tumor-infiltrated mandibular cross-sections from 10 patients. In total, 5,336 spectra were recorded at defined distances from the tumor border. Resection margins < 1 mm were defined as very close, from 1-5 mm as close, and > 5 mm as clear. The spectra were histologically validated. Based on the LIBS spectra, the discriminatory power of potassium (K) and soluble calcium (Ca) between bone-infiltrating tumor tissue and very close, close, and clear resection margins was determined.

RESULTS

LIBS-derived electrolyte emission values of K and soluble Ca as well as histological parameters for bone neogenesis/fibrosis and lymphocyte/macrophage infiltrates differ significantly between bone-infiltrating tumor tissue spectra and healthy bone spectra from very close, close, and clear resection margins (p < 0.0001). Using LIBS, the transition from very close resection margins to bone-infiltrating tumor tissue can be determined with a sensitivity of 95.0%, and the transition from clear to close resection margins can be determined with a sensitivity of 85.3%.

CONCLUSIONS

LIBS can reliably determine the boundary of bone-infiltrating tumors and might provide an orientation for determining a clear resection margin.

CLINICAL RELEVANCE

LIBS could facilitate intraoperative decision-making and avoid inadequate resection margins in bone-invasive oral cancer.

The Perfect Timing-Immediate versus Delayed Microvascular Reconstruction of the Mandible

In this retrospective study, the clinical and economic implications of microvascular reconstruction of the mandible were assessed, comparing immediate versus delayed surgical approaches. Utilizing data from two German university departments for oral and maxillofacial surgery, the study included patients who underwent mandibular reconstruction following continuity resection. The data assessed included demographic information, reconstruction details, medical history, dental rehabilitation status, and flap survival rates. In total, 177 cases (131 male and 46 females; mean age: 59 years) of bony free flap reconstruction (72 immediate and 105 delayed) were included. Most patients received adjuvant treatment (81% with radiotherapy and 51% combined radiochemotherapy), primarily for tumor resection. Flap survival was not significantly influenced by the timing of reconstruction, radiotherapy status, or the mean interval (14.5 months) between resection and reconstruction. However, immediate reconstruction had consumed significantly fewer resources. The rate of implant-supported masticatory rehabilitation was only 18% overall. This study suggests that immediate jaw reconstruction is economically advantageous without impacting flap survival rates. It emphasizes patient welfare as paramount over financial aspects in clinical decisions. Furthermore, this study highlights the need for improved pathways for masticatory rehabilitation, as evidenced by only 18% of patients with implant-supported dentures, to enhance quality of life and social integration.

Risk factors associated with fixation-related complications in microsurgical free flap reconstruction of the mandible

BACKGROUND

Hardware complications (loosening of screws, infection, or exposure of the plate) in mandibular reconstruction with vascularized osseous free flaps impose significant morbidity, and frequently require revision surgery. Purpose of this study was to identify possible contributing factors for hardware complications.

METHODS

This is a retrospective cohort study involving case series of patients who underwent microvascular mandible reconstructions between 2000 and 2020. Patient demographics, pathological, clinical, and treatment-related factors were analyzed in univariate and multivariate analyses.

RESULTS

Ninety-one patients were enrolled, encompassing 63 reconstructions with fibular free flaps, 26 reconstructions with scapular, and 2 reconstructions with iliac flaps. Rate of hardware complications and plate exposure was 14.3% and 7.7%, respectively, with a median follow-up time for extrusion of 29 months. In univariate analysis, preoperative radiotherapy (odds ratio [OR] = 6.57, p = .01), and secondary mandible reconstruction (OR = 4.3, p = .04) were significant predictors of hardware complications, and plate exposure was most frequently found in secondary reconstruction (37.5%, OR = 11.8, p = .04). Hypertension was the most commonly found comorbidity (24%), and it trended toward significance regarding plate exposure (p = .05). Only secondary mandible reconstruction was associated with osteosynthesis complications (OR = 12.53, p = .01) and plate exposure (OR = 23.86, p = .005) on multivariate analysis, while preoperative radiation therapy did not retain its relevance on plate exposure.

CONCLUSION

Secondary mandible reconstructions with vascularized osseous free flaps have a higher risk of osteosynthesis complications than primary reconstructions.

What is the Incidence of Oral Cancer Recurrence in Patients Reconstructed With a Microvascular Free Flap, Endosseous Implants, and an Oral Prosthesis and How Does the Timing of Implant Placement Influence Recurrence?

PURPOSE

In patients with malignant oral disease, there is concern that immediate implant placement at the time of ablative and microvascular free flap surgery can contribute to tumor recurrence or delay the diagnosis of recurrence. The purpose of this study is to 1) estimate the incidence of recurrence in patients with malignant disease treated with immediate microvascular free flap reconstruction, endosseous implants, and an oral prosthesis, 2) measure and compare the timing of implant placement, immediate versus delayed, and the time to complete oral rehabilitation, and 3) measure the association between the timing of implant placement and tumor recurrence.

MATERIALS AND METHODS

This is a retrospective cohort study utilizing medical record analysis involving patients with malignant oral cancer undergoing tumor resection and immediate microvascular reconstruction from 1996 to 2019 at the Mayo Clinic, Rochester, MN by the Division of Oral and Maxillofacial Surgery. Additional inclusion criteria comprised of immediate or delayed endosseous implant placement, the fabrication of an oral prosthesis, and a minimum of 2-year follow-up. Data on patient demographics, tumor characteristics, timing of implant placement and prosthesis loading, type of prosthesis, tumor recurrence, or second primary tumor events were analyzed.

RESULTS

Thirty-three patients with a mean follow-up of 6.4 years were included. Twenty-four patients (72.7%) were diagnosed with squamous cell carcinoma with 3 patients experiencing tumor recurrence. Fifteen patients had immediate implant placement while 18 patients had delayed implant placement. The mean number of days to prosthetic loading of the implants was 680.4 days and 330.1 days for the delayed implant group and immediate implant group, respectively, which was statistically significant (P = .004). The timing of implant placement and the event of a recurrence were not statistically significant (P = .075).

CONCLUSION

The incidence of recurrence in patients with malignant oral cancer treated with microvascular reconstruction, endosseous implants, and an oral prosthesis was 12.5% with one recurrence occurring beneath the oral prosthesis. Delayed implant placement resulted in a statistically significant delay in the completion of oral rehabilitation compared to immediate implant placement. There was no difference in the incidence of recurrence in the immediate implant group compared to the delayed implant group.

Multiple Sequential Free Flap Reconstructions of the Head and Neck: A Single-Center Experience

BACKGROUND

Free flap reconstruction is the standard of care in extensive defects of the head and neck area, and although most patients may be treated sufficiently with one flap, recurrence of a malignant tumor or failure of a previous reconstruction may make the use of a second (or more) flap necessary. The aim of this study was to evaluate the indications and success rates of multiple consecutive reconstructive procedures in a large cohort of patients.

METHODS

Nine hundred ninety-six free flap reconstructions were retrospectively analyzed and cases of sequential reconstructions in the same patient were identified. Indications, success rates, perioperative procedures, and frequently used flaps were evaluated.

RESULTS

Two hundred twenty cases of sequential microvascular reconstructions were identified, ranging from two to six flaps per patient. The overall flap success rate was 89.1 percent. A history of diabetes was identified as a risk factor for flap failure (p = 0.029). There was no association of flap loss with the number of reconstructive procedures per patient.

CONCLUSIONS

The use of several free flaps in the same patient is a feasible option for patients suffering from recurrent tumors or to improve quality of life by a secondary reconstruction. A salvage free flap transfer to replace a lost transplant exhibits good success rates.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Ameloblastic Carcinoma In Situ: Review of Literature and a Case Presentation in a Pediatric Patient

Ameloblastic carcinomas are rare malignant lesions with 3 mandibular pediatric cases reported in the literature. We present a case of ameloblastic carcinoma in situ in a 15-year-old male with a right mandibular cystic lesion on computed tomography. The incisional biopsy revealed plexiform ameloblastoma. Due to the infiltrating and aggressive nature of the tumor, the patient underwent hemimandibulectomy and immediate reconstruction with a vascularized osteocutaneous fibula free flap. The final pathology was read as ameloblastic carcinoma in situ. Given the rarity of this disease in the pediatric population, this case report may be a valuable addition to the current literature.

Can the inferior alveolar nerve be used as a marker in frozen section for free margin control after segmental mandibulectomy in tumour ablation?

This study critically assessed the possibility of tumour spread along the inferior alveolar nerve (IAN) and its sensitivity as an intraoperative marker for clear bony margin control in frozen section during segmental mandibulectomy. Fifteen patients with oral squamous cell carcinoma (OSCC) involving the mandible and requiring a segmental mandibulectomy were included in this prospective trial. The ends of the IAN were analyzed using quick section analysis and the results compared with those of the definite pathological report. Nerve tissue could be identified in 25 of the 27 specimens collected. No specimen revealed tumour invasion. All histological diagnoses were finally confirmed. Three positive bony margins with microscopic carcinoma infiltrates were found, whereas corresponding nerve tissue did not confirm tumour invasion. This study supports the assumption that the pattern of tumour invasion is rarely primarily along the IAN in OSCC involving the mandible. Quick section analysis of the nerve tissue alone is therefore not a valid marker for intraoperative bony margin control. However, it can be used as an additional intraoperative diagnostic tool combined with other methods in rare cases of primary tumour spread along the IAN. A review of current knowledge regarding bony margin control published in the literature is provided.