2 The procedure
2.1.1 Malignant or premalignant changes in the oesophagus may take the form of either squamous cell carcinoma or adenocarcinoma, or their respective premalignant (dysplastic) forms. In the UK, approximately two thirds of all oesophageal cancers are adenocarcinomas and one third are squamous carcinomas.
2.1.2 Depending on the type and stage of cancer or dysplasia, current treatment options include oesophagectomy, chemotherapy, radiotherapy, ablative procedures such as radiofrequency ablation, and endoscopic mucosal resection (EMR). The latter usually removes lesions piecemeal, in contrast to ESD which aims to remove lesions intact and with a margin of healthy tissue.
2.2.1 ESD is usually preceded by diagnostic endoscopy, biopsy and imaging. The procedure is done with the patient under sedation or general anaesthesia. Under endoscopic visualisation, the submucosa is injected with saline to help lift the lesion. This fluid may contain pigment to help delineate the lesion, and adrenaline to reduce bleeding. A circumferential mucosal incision is made with an electrocautery knife around the lesion. Submucosal dissection is then carried out, parallel to the muscle layer, and the lesion is removed. A transparent hood can be used to retract the already dissected part of the lesion out of the visual field. Thermocoagulation is used to achieve haemostasis. Endoscopic clips can be used for larger vessels or to manage perforation.
Sections 2.3 and 2.4 describe efficacy and safety outcomes from the published literature that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the overview.
2.3.1 A comparative case series of 136 patients treated by ESD or by 1 of 2 different EMR techniques, reported en-bloc resection rates of 100% (31/31) for ESD, and 87% (59/68) and 71% (51/72) for the two EMR procedures (p < 0.05). A comparative case series of 77 patients treated by ESD or EMR reported en-bloc resection in 91% (29/32) and 11% (5/46) of lesions respectively. Case series of 84 and 43 patients (including 107 and 58 neoplastic or dysplastic squamous lesions, respectively) reported en-bloc resection of all lesions in both series, and R0 resection (both lateral and basal margins free) in 88% (94/107) and 78% (45/58) of lesions respectively.
2.3.2 The comparative case series of 77 patients treated by ESD or EMR reported local recurrence in 4% (1/26) and 25% (11/44) of patients respectively (follow-up and significance not stated).
2.3.3 The Specialist Advisers listed key efficacy outcomes as adequacy of cancer treatment (complete resection with clear margins on histology) and survival.
2.4.1 Perforation during ESD causing pneumomediastinum was reported in 5% (4/84) of patients in the case series of 84 patients and 1 patient in the comparative case series of 136 patients (all successfully treated by antibiotics). Perforation with pneumomediastinum was reported in 7% (4/58) of lesion dissections in the case series of 43 patients: all were successfully treated by endoscopic clipping with the pneumomediastinum resolving spontaneously within a week.
2.4.2 Pneumomediastinum was reported in 6% (6/102) of cases in the series of 102, all successfully treated with antibiotics, fasting and intravenous infusion.
2.4.3 Oesophageal stricture was reported in 16% (9/58) of lesion dissections in the case series of 43 patients, all successfully treated by balloon dilatation.
2.4.4 In case series of 102 cases and 65 patients, oesophageal stenosis requiring balloon dilatation during follow-up was reported in 7% (7/102) of cases (mean follow-up 21 months) and 17% (11/65) of patients (follow-up of up to 47 months) respectively.
2.4.5 The Specialist Advisers considered possible adverse events to be aspiration pneumonia, uncontrollable bleeding and the need for emergency oesophagectomy.