Double pyramid technique of transoral laser partial laryngectomy for radiorecurrent laryngeal cancer

Abstract

Management of recurrent head and neck cancer is challenging. Surgical treatments for residual or radiorecurrent laryngeal cancer include total laryngectomy, open partial laryngectomy and transoral laser microsurgery (TLM). TLM has been shown to achieve good oncological and functional outcomes in radiorecurrent laryngeal cancer. We describe a case of a patient with radiorecurrent T2 (rT2) with impaired vocal cord mobility laryngeal cancer who underwent transoral laser partial laryngectomy using our proposed double pyramid technique. It encompasses two steps: resection of the superior and inferior pyramids. Full resection is achieved by staying close to the thyroid and cricoid cartilages. In this technique, the dissection principle is to remove anterior commissure in two pyramid fashions without having to actually follow the tumour. This method is easy and simple to master. Two years postoperatively, the patient has no signs of recurrence and is able to use her voice and has full swallowing ability.

Background

Current recommendations for the treatment of early (T1) glottic cancers involving the anterior commissure (AC) favour radiotherapy (RT) over surgery, due to better preservation of voice.¹ Reirradiation is not indicated in recurrence and surgery is often the preferred management.² Management of recurrent head and neck cancer is challenging in both surgical and oncological practice. Treatment options for residual or radiorecurrent laryngeal cancer include total laryngectomy, open partial laryngectomy and transoral laser microsurgery (TLM).³ TLM has been shown to achieve good oncological and functional outcomes in radiorecurrent laryngeal cancer when performed by expert surgeons in selected patients.⁴ This case report aims to introduce a new, technically easy and simple to master, method of partial laryngectomy using TLM and to highlight the good functional outcomes achieved by preservation surgery in selected patients to maximise quality of life following surgery.

Case presentation

A 92-year-old woman presented with a focal polyp involving the anterior two-thirds of left true vocal cord, AC and the anterior one-third of right true vocal cord with slight subglottic extension on the left side. Histopathology revealed widespread squamous cell carcinoma in situ and areas of invasive moderately differentiated squamous cell carcinoma of the glottis—T1a laryngeal cancer. At the time, she was a smoker and wheelchair user.

Investigations

CT head and neck, chest, abdomen and pelvic scan with contrast revealed no spread of cancer to laryngeal cartilage or neck lymph nodes as well as no distant metastases.

Treatment

She was initially treated with RT which is one of the two most commonly used treatment modalities in the UK with surgery in reserve.⁵ She received 60 Gy total radiation dose (2 Gy per fraction daily Monday to Friday for 6 weeks) by Intensity-modulated radiation therapy. Her 3 months follow-up flexible nasendoscopy showed recurrence of tumour and further staging workup demonstrated presence of a radiorecurrent T2 (rT2) tumour (figure 1) involving the left vocal cord with impaired mobility, the AC and the subglottic region.⁵ CT head and neck scan with contrast was performed to assess whether radiorecurrent laryngeal cancer has spread to laryngeal cartilage or neck nodes either of which were negative. Complete resection using the double pyramid technique was performed (figure 2A–C). The surgery lasted 40 min with no complications (figures 3 and 4). The patient was discharged the following day.

Figure 1.

Radiorecurrent T2 tumour involving anterior commissure, right mid 1/3 and left full vocal cord. Laser safe anaesthetic endotracheal tube posteriorly.

Figure 2.

(A) Diagram of larynx showing position of tumour with the proposed double pyramid technique. (B) Zoom in of double pyramid technique diagram of larynx. (C) Diagram of proposed double pyramid technique—three wall superior/upper/top (blue) and inferior/lower/bottom (green) pyramids.

Figure 3.

CO₂ laser surgery, accublade being used for transoral resection of superior pyramid of tumour.

Figure 4.

Full resection of tumour (superior and inferior pyramids). 1. Thyroid cartilage, 2. cricoid cartilage, 3. trachea, 4. fatty prolapse in thyrocricoid space.

Outcome and follow-up

The 6-week postoperative second look under general anaesthesia for biopsy showed no recurrence of the cancer. Thirty-two months postoperatively, there were no signs of recurrence after several 3-monthly follow-up appointments in outpatient clinic (figure 5A and B). The patient is able to use her voice and has full swallowing ability (video 1). Phonation is achieved by adduction of false vocal cords (video 2).

Figure 5.

(A)_Six months postoperative view. (B) Nine months postoperative view. Showing good healing of tissue and false cord hypertrophy allowing phonation.

Video 1.

Download video file ^{(1.1MB, mp4)}

DOI: 10.1136/bcr-2018-224915.video01

Assessment of dysphonia during postoperative follow-up appointment.

Video 2.

Download video file ^{(1.6MB, mp4)}

DOI: 10.1136/bcr-2018-224915.video02

Assessment of abduction and adduction of false vocal cords.

Discussion

Accepted treatment options for T1a-T2 glottic carcinoma with normal vocal cord mobility are RT and TLM. The treatment any patient receives depends on local multidisciplinary team (MDT) decision based on patient and tumour factors and clinical resources as local expertise.⁵

Local recurrence for glottic carcinomas rated after radiation treatment is 5%–13% for T1 and 25%–30% for T2 laryngeal cancer.^{6 7}

All patients with radiorecurrent laryngeal cancer should be examined by fiberoptic laryngoscopy and CT or MRI with assessment and examination under anaesthetic biopsies with 0°–70° rigid endoscopes under general anaesthesia.⁶ It should not be relied solely on examination and biopsies as it can be falsely negative in up to 31% patients.⁴ Ideally patients, considered for active curative treatment, should undergo positron emission tomography combined with CT (PET-CT) scanning.⁴ Each patient should be discussed at MDT meeting.⁶

Recurrent head and neck squamous cell carcinoma present some of the most challenging management issues in head and neck surgical and oncological practice as it has an aggressive course, arises in a field where lymphatic drainage is unpredictable and carries a poor prognosis.3 4 6 7 Radiorecurrent cancers tend to be infiltrative with multiple foci and perineural and intravascular invasion, lying deep below intact mucosa, undifferentiated as well as more commonly present with a higher tendency for extralaryngeal spread and subglottic extension.^6–8

Traditionally, patients with recurrence of head and neck cancer are considered to have poor prognosis.⁴ Evidence shows that recurrence of laryngeal cancer in less than 6 months has a persistent disease and much worse prognosis.^{4 9} A recurrence more than 12 months after the end of a treatment is associated with a better outcome.

Poor evidence base to support management options, the substantial implications of treatments on the function and quality of life and the difficult decision-making considerations for supportive care alone makes the treatment more challenging.⁴

The diagnosis is more challenging because of radiation caused oedema and the low specificity of conventional diagnostic strategies.^{6 8} Specific sites such as the laryngeal ventricle and the subglottic region are difficult to examine in the presence of significant oedema.⁷

It is often difficult to identify perioperative tumour margins accurately in a previously irradiated larynx.³ Some studies have revealed only 50% of accuracy of staging of recurrent tumours in comparison to pathological staging with more than 90% being understaged.^{3 8}

CT and MR imaging have a low specificity after radiation therapy as it has low accuracy for differentiating between cancer, oedema and interstitial radiation fibrosis and necrosis.^{4 6} However, either CT or MR imaging can be important for planning surgical procedures and outlining RT.⁴ MR imaging seems to be more sensitive to detect cartilage alterations than CT.⁷ The best imaging for assessment of recurrence of head and neck cancer is PET-CT scanning for local and nodal recurrence as well as distant metastasis as reported negative predictive value of PET-CT is above 93% for recurrence in the primary site and the neck as well as highly sensitive and specific for detection of distant metastasis.⁴

For these reasons, total laryngectomy is the most common treatment for radiorecurrent laryngeal cancer in the English-speaking world.^{3 6} Several centres offer total laryngectomy as the only salvage option due to concerns about higher incidence of complications in irradiated neck being the cause for surgeons to be reluctant to adapt less radical procedures; nevertheless, salvage total laryngectomy is associated with an increased risk of wound and systemic complications as one of major ones being pharyngocutaneous fistulae in 15%–80% cases after either RT or chemoradiotherapy.^{3 4 6}

Advances in functional surgery have encouraged head and neck surgeons to treat tumour recurrences whenever possible by voice preservation salvage surgery.⁸

Open partial laryngectomy has a well-defined role both for primary and radiorecurrent laryngeal cancer but it is not widely practiced due to technical complexity, lack of expertise and unpredictable functional outcomes.³ Surgical salvage in the form of total laryngectomy has been traditionally the gold standard for radiorecurrent laryngeal cancers; however, in the recent decades, the attention to function preservation and the conservative approaches are gradually replacing total laryngectomy as primary treatment, in favour of radiation, chemoradiation and conservative treatment.^{6 10}

TLM as a salvage conservation laryngeal surgery may be considered as a more functional alternative to total laryngectomy. Recently, it has become more acknowledged treatment modality, although less data of treatment outcomes are available for specifically selected patient groups with laryngeal cancer.¹⁰

TLM is effective and safe in patients with early stage radio-recurrent laryngeal cancers.^{3 10} The use of endoscopic laser surgery is continuously evolving. TLM has a well-defined and proven role in the management of primary laryngeal cancer.³ In 1992, Eckel and Thumfart concluded that surgery could only be performed in selected T1 and T2 tumours of laryngeal cancer.¹¹ Since then some authors have expanded the use of TLM to include both advanced-stage and radiorecurrent laryngeal cancers.^{3 11} TLM can be repeated for residual or recurrent disease despite the relatively poor local control rates compared with open partial laryngectomy—it is about 30% less inferior than open partial laryngectomy.^{3 4}

In contrast to the more traditional en bloc oncological prototype, TLM involves an incisional resection technique. The dissection is performed piece by piece, dividing the tumour repeatedly, thus allowing the surgeon to accurately excise the whole tumour preserving cancer-free tissue and allowing greater preservation of healthy tissues, structure and function.¹¹

More aggressive resection of tumour is necessary in the salvage setting for clear margins.¹⁰ The double pyramid technique encompasses two steps: resection of tumour in superior and inferior pyramids (figure 2A–C). In our patient, full resection was achieved by staying close to the thyroid cartilage (figures 6 and 7) and cricoid cartilage, including perichondrium in resected specimen. As surgical prophylaxis to prevent chondronecrosis and perichondritis, we administered 400 mg ciprofloxacin intravenously at the time of induction of general anaesthesia. In this technique, the dissection principle was to remove structures, without having to actually follow the tumour, in two pyramid fashion—a peak of the superior pyramid is upward facing which was cranial end, corresponded to superior part of AC, and a peak of the inferior pyramid was downward facing which was caudal end, corresponded to subglottis. The bases of both pyramids are common, exactly where tumour was dissected through horizontally (figure 2A–C). After the resection pyramidal specimens were glued in the base. This orientation of specimen helped the pathologist. As in any oncosurgical treatment, the aim is to remove the whole tumour with wide clear margins which can exactly be provided with our described technique in selected patients.⁴

Figure 6.

Landmarks of dissection of superior pyramid (green line) for the tumour resection.

Figure 7.

Landmarks of dissection of superior pyramid (green line) and inferior pyramid (blue line) for the tumour resection.

Novelties of this technique are that, dividing a tumour in two portions provides easier manipulation of the tumour and giving more visibility and space in the limited narrow operating field. Resection of a tumour with this technique allows better orientation of a specimen for pathologist. When performed by an experienced surgeon, operating time is significantly reduced.

There is a robust statistically significant association between prolonged operative time and complications across surgical specialties. Prolonged operative time exceeding 2 hours approximately double likelihood of complications. Novel strategies that reduce operative times and further improve the quality of perioperative care should be considered. Reduced operative times should be a common goal for surgeons, hospitals and policy-makers.¹²

Our patient was discharged home the next day after undergoing the procedure, thus, minimising risk of developing complications and hospital stay that result in improving patient’s quality of life as well as cost savings. Great benefit of TLM is early discharge in comparison to open surgery.

Prior to the discharge, the patient was assessed by speech and language therapist (SALT) due to a risk of aspiration. It revealed that she has no signs of it. In our department, all patients undergoing similar procedures are assessed by SALT, including flexible endoscopic evaluation of swallowing when indicated.

Patients with AC involvement have marginally worse oncological outcomes with TLM than without AC involvement. Based on our experience, we believe double pyramid technique TLM can provide better local control of a cancer with AC involvement as it provided good outcome for our patient.

AC involvement should not be considered an absolute contraindication to salvage TLM on the condition that tumour exposure is adequate.^{3 10} Han et al propose that TLM is appropriate for the treatment of rT1a and rT1b lesions involving the AC, but promote an external approach for rT2 lesions with AC involvement but De Virgilio et al literature review showed that TLM can be indicated as well for rT2 tumours with normal cord mobility but not for rT2 with impaired cord mobility.^{6 10} Ramakrishnan et al’s literature review revealed TLM is applicable for earlier stage recurrent lesions (rT1/rT2) not exactly specifying presence of impaired vocal cord mobility.³

We want to emphasise that our patient had rT2 with impaired mobility of left vocal cord when she underwent double pyramid TLM resection and she has not had recurrence of the cancer for 32 months since then.^{6 13} Thus, rT2 with impaired vocal cord mobility should not be an absolute contraindication for TLM from our experience in contrast to propositions by Han et al, De Virgilio et al and Marioni et al.^{6 7 10}

In our patient’s case, the cancer recurred 3 months after RT, nevertheless, her outcome after salvage TLM has provided 32 months good quality of life without recurrence of the cancer. It is likely that double pyramid TLM technique can provide better clear margins as the dissection does not follow the tumour, instead it follows anatomical landmarks of inner larynx. Performing second look biopsies after TLM procedure is part of our institutional policy that usually takes place 6 weeks after the operation. Due to potential multifocal growth of radiorecurrent cancers, there can be higher rate of falsely negative results. Frequent follow-up every 3 months initially for first year is a good strategy for surveillance of the cancer management. It might change in future, thanks to high definition flexible scopes helping to monitor tumour recurrence in outpatient clinic warranting biopsies if any concerns are present.

It is likely that residual disease may still be present accounting for higher locoregional failure with TLM; thus, conventional margins used during TLM in the treatment of primary laryngeal cancer may well not be applicable in the radiorecurrent setting.³ We think double pyramid TLM technique is a good way to achieve good local control for rT1a-rT2 (including impaired vocal cord mobility) glottic cancers still providing good voice and swallowing function. Most patients achieve satisfactory swallowing function eventually and experience dysphonia as in our patient’s case (video 1).⁵

TLM approach is associated with less postoperative complications like pharyngocutaneous fistulae and systemic complications as skin is not breached and all procedure is done endoscopically within the larynx and based on shorter operative time, respectively. Open neck salvage partial and complete laryngectomy of radiorecurrent laryngeal cancer is associated with longer stays in hospital due to higher complication rate and slower wound healing.^{4 6 7}

Advantages of double pyramid TLM technique

• more visibility and space allowing easier manipulation,

• better orientation of a specimen for pathologist,

• oncologically accepted to cut through tumour with CO₂ laser,

• less airway bleeding,

• less postoperative complications as fistulae.

Disadvantages of double pyramid TLM technique

• requires equipment,

• laser safety (team and anaesthetic),

• cutting through tumour with scalpel is not acceptable and thus needs to be laser,

• might require second look biopsy.

Other management options

• conservative management,

• external partial laryngectomy,

• total laryngectomy.

Learning points.

• Transoral laser microsurgery (TLM) is a surgical treatment option to achieve good laryngeal organ and function preservation.

• TLM is a more tolerable surgical option than external partial or total laryngectomy with less intraoperative time, quicker postoperative recovery and less postoperative complications.

• TLM is appropriate for rT1a and rT1b lesions of larynx and, is also appropriate in our patient’s case for rT2 lesions with impaired vocal cord mobility and anterior commissure involvement.

• Double pyramid technique has several advantages in comparison to conventional TLM regarding resection of the tumour with clear margins—less bleeding, better orientation of the specimen for histopathological examination and others.

• Appropriate equipment is necessary to perform TLM as well as surgeon and scrub staff needs to be trained to use the laser safely.