Systematic review of incidence, risk factors, prevention and treatment of post-laryngectomy hypoparathyroidism

The impact of detecting and autotransplanting parathyroid gland with near-infrared imaging during total laryngectomy with total thyroidectomy

OBJECTIVE

Persistent postoperative hypoparathyroidism (hypoPT) after total thyroidectomy (TT) is a serious complication necessitating lifelong treatment. HypoPT would be more serious when combined with total laryngectomy (TL), since in situ preservation nor autotransplantation of parathyroid glands (PGs) is not always attempted. This study examined the accuracy of identifying PGs using near-infrared fluorescence imaging (NIFI) and assessed the oncological safety and impact of PG autotransplantation on hypoPT in TL+TT.

METHODS

This prospective study was conducted between June 2020 and November 2023 at three hospitals in Niigata, Japan. Twelve patients who underwent TL+TT were included. Specimens were evaluated for autofluorescence (AF) using NIFI ex vivo followed by histological examination. Levels of albumin-corrected calcium and intact parathyroid hormone (PTH) were monitored postoperatively.

RESULTS

Twenty-nine AF-positive tissues were identified as possible PGs using NIFI. Histological examination revealed that 27 were PGs and 2 were adipose tissues: 0-5 (median=2) PGs were autotransplanted per patient. All 272 tissues isolated as lymph nodes by the surgeon's visual inspection were negative for AF, none of which were PGs by histological examinations. Therefore, NIFI exhibited 100 % sensitivity and 99 % specificity for PG identification. The rate of persistent postoperative hypoPT was 33 % (4/12). After a median follow-up of 42 months (range 16-54 months), no tumor recurrence was observed in the sites of parathyroid autotransplantation.

CONCLUSION

This study demonstrated the high accuracy of NIFI in identifying PGs during TL+TT. PG autotransplantation with NIFI assistance emerged as a viable technique for mitigating postoperative hypoPT in TL+TT procedures.

Investigating the Incidence and Risk Factors of Hypocalcemia After Laryngectomy

Background

Laryngeal cancer is a common advanced head and neck cancer. Surgery, radiation, chemotherapy, or a combination of these treatments are used to treat locally advanced laryngeal cancer. Total laryngectomy is generally preferred for T3-4 laryngeal cancers, despite being an invasive procedure. Post-surgical hypocalcemia is a known complication of neck compartment surgeries, and patients who have undergone laryngectomy are at a higher risk of developing hypoparathyroidism, leading to hypocalcemia. This study aims to investigate the prevalence and risk factors of hypocalcemia in individuals following laryngectomy.

Method

This retrospective study examined 50 consecutive laryngectomy patients over eight years. Data on demographic characteristics, medical history, surgical details, pre-and post-operative calcium levels, neck dissection laterality, history of radiotherapy were collected. Hypocalcemia was defined as calcium levels < 8.5 mg/dl or corrected calcium < 8.5 mg/dl. Statistical analyses included paired t-tests, Wilcoxon signed-rank tests, and binary logistic regression using R studio.

Results

The mean age of participants was 59 years, predominating males (94%) and habitual smokers (94%). Squamous cell carcinoma was the most prevalent (98%) pathological diagnosis, and various surgical techniques were employed. While initial comparisons showed no significant changes in calcium levels pre-and post-operatively, adjusting for albumin levels revealed a significant association. Logistic regression identified neck dissection, low pre-operative calcium, radiotherapy, and total thyroidectomy as significant predictors of post-operative hypocalcemia (p < 0.05).

Conclusion

Surgical factors such as neck dissection and total thyroidectomy, alongside albumin levels, significantly impact postoperative hypocalcemia. These findings underscore the need for meticulous monitoring and potential preventive measures to manage calcium imbalance post-laryngectomy.

Extralaryngeal Spread in Total Laryngectomy: Comparing the Need for Thyroidectomy

Objective: At our institution, thyroid preservation during total laryngectomy (TL) varies by surgeon, offering a distinctive dataset to compare disease outcomes in TL patients with or without thyroidectomy. Methods: This retrospective chart review study, conducted at a tertiary referral medical center, comprises patients who underwent TL for laryngeal or hypopharyngeal squamous cell carcinoma from 2014 to 2022. The study includes data on patient demographics, surgeries, pathological staging, tumor subsites, thyroid involvement, and adjuvant therapy. Results: In this study, 147 patients, mostly male (83%) and white (82%), were included. Surgeries comprised 60 hemi thyroidectomies, 35 total or completion thyroidectomies, 48 without thyroid removal, and 4 isthmusectomies. Data analysis compared these 4 groups and the cohort of no thyroid removal (NT) versus any thyroidectomy (T = 99). Among the 99 patients, 27 showed positive gland involvement, primarily due to direct disease extension (26 cases). No significant difference was found in recurrence rates or recurrence-related mortality among the 4 groups or between NT and T (P = .156). However, there was a significant difference in T staging and prognostic staging among the groups and between NT versus T (P = .043). The NT cohort showed a higher likelihood of being T3, while T was more likely to be T4. Conclusion: We found no significant difference in recurrence rates or mortality between TL patients with or without thyroid removal. However, those without thyroid removal often had lower T stages. Notably, 27% of thyroidectomy patients had gland invasion, highlighting the importance of thyroid removal in TL.

Evaluation of Hypocalcemia Following Total Laryngectomy With and Without Thyroidectomy

OBJECTIVE

Hypoparathyroidism and associated hypocalcemia are well-established complications following laryngectomy. This study further characterizes the rates of hypocalcemia in patients undergoing total laryngectomy (TL) with and without thyroidectomy and hemithyroidectomy.

STUDY DESIGN

Retrospective cohort study.

SETTING

TriNetX.

METHODS

We queried TriNetX, a deidentified patient database, to identify patients who underwent TL with and without thyroidectomy and hemithyroidectomy. Rates of hypocalcemia, low parathyroid hormone (PTH), calcium, and calcitriol supplementation were compared between groups with multivariable repeated measures logistic regression.

RESULTS

We identified 870 patients in the TL without thyroidectomy cohort, 158 patients in the hemithyroidectomy cohort, and 123 in the total thyroidectomy cohort. Rates of hypocalcemia differed between patients receiving total thyroidectomy versus TL alone for 0 to 1 month (odds ratio [OR]: 2.88 [1.95-4.26]) 1 to 6 months (OR: 5.08 [2.29-11.3]), and 6 to 12 months (OR: 2.63 [1.003-6.88]) postoperatively, with adjustment for age at laryngectomy, race, ethnicity, and gender. Results were similar among those who received calcium supplementation. The rate of low PTH levels differed in these groups for 0 to 1 month (OR: 5.13 [3.10-8.51]), 1 to 6 months (OR: 3.47 [1.46-8.22]), and 6 to 12 months (OR: 3.63 [1.40-9.38]) following surgery. Rates of postoperative calcium supplementation were increased for patients receiving total thyroidectomy versus TL for 1 to 6 months (OR: 2.44 [1.62-3.68]), and 6 to 12 months following surgery (OR: 1.79 [1.18-2.72]).

CONCLUSION

Patients undergoing TL with total thyroidectomy have a higher risk of postoperative hypocalcemia compared to patients receiving TL alone. Risk of parathyroid injury in these patients may warrant further emphasis on PTH measurement after surgery and a multidisciplinary approach to management.

Intensive care of a patient undergoing combined multi-organ cluster ("larynx-trachea-thyroid-hypopharynx-esophagus") transplantation: A case report

OBJECTIVE

The aim of this study was to summarize the intensive care experience of a patient undergoing combined multi-organ cluster ("larynx-trachea-thyroid-hypopharynx-esophagus") transplantation.

METHODS

The intensive care management plan for this case was developed by a multidisciplinary team, with focus on 6 aspects: (1) stabilizing the circulation and reducing anastomotic tension by position management to improve the survival chances of transplanted organs, (2) adopting goal-directed analgesia and sedation protocols, as well as preventing anastomotic fistula, (3) implementing a bedside ultrasound-guided nutrition plan, (4) employing "body-mind" synchronous rehabilitation to facilitate functional recovery, (5) taking antirejection treatment and protective isolation measures, (6) monitoring and nursing thyroid function.

RESULTS

During the intensive care, the patient's vital signs were stable. The patient was successfully weaned from the ventilator and transferred to the general ward for further treatment at 9 days postoperatively, and discharged upon recovery at 58 days postoperatively. The patient was in good condition during follow-up.

CONCLUSION

This study provides reference for the care of patients who undergo similar transplantation in the future.

[First experience of applying domestic video fluorescent equipment for visualization and blood flow evaluation of the parathyroid glands]

In recent years, predictive methods for assessing the preservation of the parathyroid glands have been actively implemented. The article describes the first experience of evaluating the blood supply of the parathyroid glands by quantitative determination of the indocyanine green (ICG) accumulation index in real time in 6 patients before and after a thyroidectomy with central neck lymph node dissection for papillary thyroid cancer. Intraoperative fluorescent angiography was performed by using domestic equipment with a fluorescent module, as well as by using a domestic medication of ICG. Intraoperative values of the ICG accumulation index were compared with the levels of ionized calcium and parathyroid hormone perioperatively. No clinical manifestations of hypocalcemia were detected in the postoperative period. The obtained results showed the informativeness of the numerical assessment of the intensity of ICG fluorescence. The evaluation of the distribution (accumulation) of ICG has prospects for practical application in thyroid surgery in the formation of tactics for preserving the parathyroid glands and predicting postoperative hypoparathyreosis.

Emerging Imaging Technologies for Parathyroid Gland Identification and Vascular Assessment in Thyroid Surgery: A Review From the American Head and Neck Society Endocrine Surgery Section

Importance

Identification and preservation of parathyroid glands (PGs) remain challenging despite advances in surgical techniques. Considerable morbidity and even mortality result from hypoparathyroidism caused by devascularization or inadvertent removal of PGs. Emerging imaging technologies hold promise to improve identification and preservation of PGs during thyroid surgery.

Observation

This narrative review (1) comprehensively reviews PG identification and vascular assessment using near-infrared autofluorescence (NIRAF)-both label free and in combination with indocyanine green-based on a comprehensive literature review and (2) offers a manual for possible implementation these emerging technologies in thyroid surgery.

Conclusions and Relevance

Emerging technologies hold promise to improve PG identification and preservation during thyroidectomy. Future research should address variables affecting the degree of fluorescence in NIRAF, standardization of signal quantification, definitions and standardization of parameters of indocyanine green injection that correlate with postoperative PG function, the financial effect of these emerging technologies on near-term and longer-term costs, the adoption learning curve and effect on surgical training, and long-term outcomes of key quality metrics in adequately powered randomized clinical trials evaluating PG preservation.

Intraoperative Autofluorescence Imaging for Parathyroid Gland Identification during Total Laryngectomy with Thyroidectomy

OBJECTIVE

Hypoparathyroidism is a known complication of total laryngectomy, although parathyroid preservation and/or reimplantation are not routine. Autofluorescence is a new technique for identifying parathyroid glands intraoperatively. The aim of this study was to evaluate the feasibility of autofluorescence in this context.

MATERIALS AND METHODS

A retrospective study of patients undergoing total laryngectomy/pharyngectomy with concomitant thyroidectomy using the Fluobeam^® (Fluoptics, Grenoble, France) and frozen section of a parathyroid fragment in case of reimplantation. The rates of identification using autofluorescence, reimplantation, and hypoparathyroidism were evaluated.

RESULTS

Eighteen patients (16 males, median age 67) underwent total laryngectomy/pharyngectomy with total thyroidectomy (n = 12) or hemithyroidectomy (n = 6). A median of 2 parathyroid glands were identified per patient. Ninety-two percent were identified by autofluorescence before visualisation. All parathyroids were reimplanted due to devascularization. Temporary hypoparathyroidism occurred in nine patients, and was permanent in one patient. After 34 months of median follow-up (range 1-49), no tumor recurrence was observed in the reimplantation sites.

CONCLUSIONS

To our knowledge, this is the largest study to evaluate autofluorescence during total laryngectomy with thyroidectomy. No tumor recurrence occurred in the sites of parathyroid reimplantation.

Evaluation of hypoparathyroidism following laryngectomy

BACKGROUND

Hypoparathyroidism is a recognised complication following laryngectomy; it is associated with significant short-and long-term morbidity. This study aimed to further characterise this condition, identify risk factors and describe preventative and management strategies in a large cohort.

MATERIALS AND METHODS

This was a retrospective study at a tertiary referral centre for head and neck cancers. All consecutive patients who had total laryngectomy over an eight-year period were included.

RESULTS

A total of 140 patients were included. Rates of transient and long-term hypoparathyroidism were 14.3% and 10.1%, respectively. The following factors were significantly associated with transient post-surgical hypocalcaemia or hypoparathyroidism: total thyroidectomy (relative risk, RR, 4.33; 95% confidence interval, CI, 1.86-10.10), oesophagectomy (RR 6.05; 95% CI 2.92-12.53) and female sex (RR 3.23; 95% CI 1.45-7.19). In addition, total thyroidectomy (RR 5.89; 95% CI 1.94-17.86), central neck dissection (RR 3.97; 95% CI 1.42-11.10), oesophagectomy (RR 9.38; 95% CI 4.13-21.3), pharyngectomy (RR 7.14; 95% CI 2.08-24.39) and female sex (RR 5.52; 95% CI 1.95-15.63) were risk factors for long-term hypoparathyroidism. There was variability in the use of preventative measures, monitoring and management of hypocalcaemia and hypoparathyroidism following total laryngectomy.

CONCLUSIONS

Transient hypocalcaemia and long-term hypoparathyroidism occur in a significant proportion of patients after laryngectomy. A standard protocol is required to improve care.

The use of near-infrared autofluorescence during total laryngectomy with hemi- or total thyroidectomy

PURPOSE

The aim of this study is to describe the use of near-infrared autofluorescence (NIR-AF) to identify and preserve parathyroid glands (PGs) in a group of patients with advanced hypopharyngeal/laryngeal cancer undergone total (pharyngo)laryngectomy with hemi- or total thyroidectomy.

METHODS

At San Raffaele Hospital, Milan (Italy), from January 2021 to May 2021, 7 patients affected by cT4a laryngeal squamous cell carcinoma (SCC) underwent surgery using an autofluorescence detection system (Fluobeam-Fluoptics^®). For proper surgical planning, the demolition phase envisaged extension of the intervention to 4 hemithyroidectomies and 3 total thyroidectomies associated, respectively, with homolateral or bilateral CCND. Serum calcium, ionized calcium, and parathyroid hormone (PTH) levels at post-operative day (POD) 1 and 2 and at 2 weeks after surgery were monitored. Finally, we compared the data obtained with a cohort of patients who underwent surgery without the adoption of NIR-AF.

RESULTS

With the use of NIR-AF, 18/20 PGs were identified, of which 7/18 were preserved exclusively thanks to the use of autoflorescence. The technique also made it possible to identify and isolate three PGs from the surgical specimen, which were subsequently transplanted only after intraoperative histological confirmation. On POD-1, 3/7 patients (42.8%) were hypocalcemic; on POD-2 and after 2 weeks only 1/7 patient (14.2%) was hypocalcemic. Comparing the two groups, we highlighted that the utilization of NIR-AF was related to a significant decrease of median serum (p = 0.026) and ionized calcium levels (p = 0.017) 2 weeks after surgery. Using this new technology, in no case did definitive histological examination reveal the presence of PGs in the surgical specimen, reaching an accuracy of 100%.

CONCLUSIONS

In our cohort of patients who underwent total (pharyngo)laryngectomy with hemi- or total thyroidectomy, the use of near-infrared autofluorescence improved medium term postoperative hypocalcemia rates. This new technology helps to achieve a better calcemic outcome compared to the standard naked eye approach, since it helps the surgeon to identify and preserve parathyroid glandular tissue with a lower incidence of post-operative hypocalcemia.

Near-Infrared Autofluorescence Imaging in Thyroid Surgery: A Systematic Review and Meta-Analysis

OBJECTIVE

This meta-analysis aimed to assess the position of near-infrared autofluorescence (NIRAF) imaging in the recognition and protection of the parathyroid gland (PG) during thyroidectomy.

METHODS

The PubMed, MEDLINE, EMBASE, Web of Science, and Cochrane Library databases were searched up to June 2021. The primary outcome was to evaluate the rates of postoperative hypocalcemia, inadvertent PG resection, and autotransplantation of PG when adopting NIRAF imaging compared with standard naked-eye (N-E) surgery.

RESULTS

Eight studies with 2,889 patients were enrolled in the analysis. Our analysis showed that the incidence of transient hypocalcemia was 7.11% (60/844) in the NIRAF group and 22.40% (458/2045) in the N-E group (p < 0.0001) and the rate of transient hypoparathyroidism was 28.31% (126/445) and 33.36% (496/1487) in the NIRAF and N-E groups (p = 0.0008). The rate of inadvertent resection of PGs was 7.65% (55/719) in the NIRAF group and 14.39% (132/917) in the N-E group (p < 0.0001). No significant difference was observed in other indexes including the pooled proportion of permanent hypocalcemia and rate of PG autotransplantation.

CONCLUSIONS

The application of NIRAF imaging in thyroidectomy can help lower the incidence of inadvertent PG resection and reduce the risk of postoperative hypocalcemia and hypoparathyroidism compared with N-E recognition.

Hypocalcaemia in pharyngolaryngectomy: Preservation or autotransplantation of parathyroid glands

OBJECTIVE

To describe transient and permanent hypocalcaemia following partial and total pharyngolaryngectomy with parathyroid gland preservation or autotransplantation.

METHODS

Thirty patients underwent partial or total pharyngolaryngectomy by a single surgeon during the period 2009-2020. Intraoperative parathyroid gland preservation or autotransplantation (where the gland appeared devascularized) was routinely performed. Calcium levels performed on day 1, 3 months, and at 12 months postoperatively were collected. Rates of transient and permanent hypocalcaemia were calculated.

RESULTS

A total of 13% of patients had transient hypocalcaemia, and 10% permanent hypocalcaemia. Rates of transient and permanent hypocalcaemia in total pharyngolaryngectomy were 14% and 14%, respectively. Partial pharyngectomy hypocalcaemia rates were 13% for transient and 0% for permanent. The majority of patients underwent salvage surgery for oncological resection, often following radiotherapy (63%). Ipsilateral hemithyroidectomy was preferred to total (57% vs 7%), with high rates of concurrent neck dissection (67%) and reconstruction (87%).

CONCLUSION

This data supports preservation or autotransplantation of parathyroid glands as a means of reducing permanent postoperative hypocalcaemia.

LEVEL OF EVIDENCE

Level IV, case series, retrospective.

[Postoperative hypocalcemia - the most common complication of endocrine head and neck surgery: acute management]

BACKGROUND

In Germany, 8000 patients are affected by postoperative hypoparathyroidism per year following surgery of the thyroid gland, parathyroidal glands and the larynx. Patients do not only suffer from paresthesia in the acute phase of this complication, but are also adversely affected by the fear of loss of control following episodes of tetany even years after the first episode.

OBJECTIVES

Discussion of a diagnostic pathway and presentation of a management pathway for postoperative hypocalcemia.

METHODS

Narrative review, analysis and discussion of current literature and expert recommendations.

RESULTS

Early determination of calcium and parathyroid hormone allows timely diagnosis and treatment of postoperative hypoparathyroidism. Active vitamin D is pivotal for the resorption of calcium. Only the combined treatment with active vitamin D and calcium can mitigate or prevent the postoperative drop of calcium levels.

CONCLUSIONS

A standard operating procedure (SOP) for postoperative hypoparathyroidism should be implemented in every surgical department. An SOP for diagnosis and treatment of postoperative hypoparathyroidism is proposed for institutional individualization and implementation.