Oesophageal cancer is an aggressive condition, resulting in the vast majority of patients
having evidence of locally invasive, irresectable disease or distant metastases at the time
of presentation. Overall survival remains poor. Management in the South African setting is
plagued by late presentation of these patients, with less than 5% being eligible for curative
treatment and median survival from the time of diagnosis being only 15 weeks, while those who
present with complete obstruction having a median survival of only 75 days (10.7 weeks).
Treatment of these patients in the South African setting remains predominantly palliative.
The most common and debilitating symptom of advanced oesophageal malignancy is progressive
dysphagia, which can be addressed by the endoscopic placement of self-expanding metal stents.
The major drawback of stenting tumours in the lower oesophagus or oesophagogastric junction
(OGJ), is the associated gastro-oesophageal reflux (GOR) resulting from the stent crossing
the lower oesophageal sphincter and essentially negating the native anti-reflux mechanism.
Significant reflux is the most common complaint worsening quality of life after stent
placement in these patients and can be as high as 100% in some series. Prescribing routine
proton pump inhibitors (PPIs) or placing stents with built-in anti-reflux mechanisms are
methods aimed at reducing this symptomatic reflux.
Theoretically, oesophageal stents containing an anti-reflux valve should provide a physical
barrier to prevent gastric content (which may be acidic or non-acidic) refluxing into the
oesophagus, but whether this results in decreased rates of GOR in reality is somewhat
controversial. To date, a number of trials have compared a range of anti-reflux oesophageal
stents to conventional oesophageal stents and although there have been some conflicting
results, a systematic review and meta-analysis in 2019 concludes that GOR is not
significantly reduced by the use of anti-reflux stents. However, there are a number of
factors that must be mentioned before this conclusion can be applied to dictate clinical
practice. Firstly, the included trials all have reasonably small participant numbers, with 65
patients being the highest number of patients enrolled in any of these trials. In fact, the
authors conclude that the meta-analysis is underpowered. Furthermore, the type of anti-reflux
stent used varies with almost every trial and may well influence efficacy of reducing GOR.
Anti-reflux medical therapy such as the use of proton pump inhibitors (PPIs) also varied
greatly amongst the studies. Some prescribed PPIs only to the conventional stent group,
others did not use PPIs in either group, while the rest did not mention whether PPIs were
routinely given or not. This could possibly influence symptomatic reflux and act as a
significant confounding factor.
The measurement of GOR in the trials assessed in this meta-analysis shows significant
heterogeneity, with some studies using patient questionnaires (some of these assess quality
of life in general and do not specifically focus on reflux symptoms), others use contrast
oesophagography or functional 24-hour pH monitoring. These additional factors make the
results of this underpowered meta-analysis difficult to interpret. Since then, a further
randomised controlled trial (RCT) was conducted by Dua et al. This included a total of 60
patients, comparing a novel tricuspid-shaped valve anti-reflux stent (30 patients) to
conventional stenting (30 patients). Importantly, this trial was a non-inferiority trial to
assess safety and efficacy at improving dysphagia for the new stent. Assessment of GOR was a
secondary outcome and although reflux rates favoured the new anti-reflux stent, this did not
reach statistical significance. The current level I and II evidence on reducing GOR with
anti-reflux stents is thus not definitive and leaves the topic unresolved.
While research in high income countries is focused on the management of early oesophageal
malignancies, this is not appropriate in the South African setting where the vast majority of
patients are irresectable at initial presentation. Local research is significantly limited
and there is a paucity of data from South Africa, and Africa as a whole, as regards the
palliative management of malignant oesophageal dysphagia. Specific evidence on the use of
anti-reflux stents is absent. Further research is thus invaluable in assessing if the
palliative care of these patients can be improved by using anti-reflux stents.
This prospective randomised controlled trial aims to compare the incidence of symptomatic
volume GOR after the use of anti-reflux oesophageal covered metal stents versus conventional
oesophageal covered metal stents for lower oesophageal malignant strictures in a South
African tertiary referral centre with a high rate of palliative stenting for advanced
oesophageal carcinoma. Reflux will be assessed subjectively by the administration of patient
questionnaires aimed at identifying severity of acid reflux, but also the degree of
dysphagia, pain and coughing before and after stent placement. Reflux will also be assessed
objectively by using oesophageal scintigraphy performed shortly after stent insertion.
Scintigraphy has not previously been used to measure GOR in these patients and is chosen for
its accuracy and non-invasive nature (compared to, for example, pH monitoring which requires
the placement of an uncomfortable nasal probe for 24 hours and is considered inappropriate in
this cohort where the main focus lies on quality of life).
