SAGES Magazine

THE SOUTH AFRICAN GASTROENTEROLOGY REVIEW 2021 | VOLUME 19 | ISSUE 2 | 15 Variceal bleeding Variceal bleeding (VB) remains a serious complication of portal hypertension with high morbidity and mortality rates. Initial management principles consist of early resuscitation, vasoactive drugs (terlipressin, ocreatide, etc), antibiotic prophylaxis, and early endoscopic management in the form of variceal banding ligation or sclerotherapy. Previously, in the case of massive haemorrhage unresponsive to early medical, endoscopic and or radiologic interventions, balloon tamponade (BT) was utilized to attempt haemostasis. Current guidelines however recommend the placement of a fully covered large-diameter 30mm SEMS. 22 Escorsell et al. directly compared BT versus the self-expandable metal SX-ELLA Danis stent for VB in a randomised control trial. Therapy was more successful in the stent group (66% vs 20%), with higher control of bleeding (85% vs 47%) and less adverse events (15% vs 47%). 37 A retrospective, national multi-center trial conducted by Pfisterer et al. further evaluated the efficacy and safety of SX-ELLA Danis stents for refractory VB. Bleeding was controlled in 79.4% of patients, however rebleeding occurred in 17.6%, with a bleeding-related mortality of 47.1% and a median survival after SEMS placement of only 2.1 months. 38 The poor outcomes highlight the severity of the underlying disease, and for this reason SEMS are proposed as a bridge to early transjugular intrahepatic portosystemic shunting (TIPS) or liver transplant. Stent-in-stent (for removal of partially covered SEMS) As mentioned in the preceding text, tissue hyperplasia and overgrowth are complications of partially covered SEMS. In the case where a partial covered SEMS needs to be removed a stent-in-stent technique can be utilised. This involves deploying a fully covered SEMS of the same diameter as the embedded stent, into the embedded stent. Because the embedded stent is fully overlapped by the inner SEMS, pressure necrosis ensues allowing safe removal of both stents in 91% of patients in 10-14 days. 39 Paediatric disease The most common strictures occurring in the paediatric population are due to anastomotic strictures (post oesophageal atresia/ trachea-oesophageal fistula (TOF) repair), accidental caustic ingestion, reflux oesophagitis and less frequently achalasia and epidermolysis bullosa. A retrospective study and systematic review was conducted by Tandon et al. to identify the role of stenting in these scenarios. 40 Different stents were used across the various studies including fully covered SEMS, SEPS and BD stents. Results were inconclusive. In the systematic review, stenting alone managed to resolve 52% of oesophageal strictures with no further intervention required, however the follow up duration was short (under 4 years). In the retrospective cohort, the median follow- up time was 6.7 years, with 76% of patients requiring further treatment, 32% requiring oesophageal replacement, and only 8% receiving no further treatment. The use of oesophageal stents for refractory strictures can therefore only be considered on a case-by-case basis. There may be a role in anastomotic leaks and recurrent TOF. Further, stenting could be used as a bridge to definitive surgery however the re-intervention rates are high with unlikely complete resolution of the stricture with stenting. The ideal stent At present, with numerous available stents, each with their own characteristics and function, it is difficult to decide which one is the “perfect’ stent. Despite ongoing intense industry competition, the reality is that the perfect stent does not yet exist. Contrary to the original views in 1959, where stents were “essentially meant for the inoperable, and should not be misused” 1 ; currently, with advances in technology, the indications for stenting the oesophagus have widely expanded and they are being utilized in various oesophageal pathologies. This expansion has occurred for two reasons. Firstly, there is improved oncological management of oesophageal and gastro- oesophageal malignancies, resulting in greater patient longevity and the need for adjunctive treatments to manage complications. Stents are therefore required to function and last longer to avoid repeat procedures. 16 Secondly, an array of “benign” pathologies which carry a high surgical morbidity and mortality have led to the use of stenting in the treatment armamentarium, as either a definitive solution or a bridge prior to, or combined with further interventions. The desire to have one ideal stent for all indications may be too much to ask for at this time. Despite rapidly advancing stent technology, the ideal stent remains elusive. Several limiting factors remain, both with current stent technology and the body’s response to them. In 1973 Didcott had already noted that the ideal stent “should be stable, comfortable, wide enough not to cause blockage, and, if possible, not cause reflux by transgressing the cardio- oesophageal junction.” 9 These basic requirements have not changed in modern day, however, additionally the stent should be easy to accurately deploy through a small access system, stay in place by expanding reliably, reduce tumour or tissue ingrowth and over- growth, and be removable if so desired, while causing minimal to no discomfort, and allowing normal peristalsis. 15 Further needs include focusing on reducing complication rates by improving stent design, using different materials or coverings, or creating hybrid stents. In the future, stents will hopefully do more than just pry open a stricture or cover a defect in the oesophageal lumen; a possibility includes drug delivery and providing local therapy. The ultimate goal of the oesophageal stent of the future would be a tailored stent, at a low cost, that both treats the underlying condition and restores oesophageal function to near normal. 18 Conclusion Oesophageal stents have greatly changed over the years from d’Etiolles’ archaic, ivory stent to a modern-day armamentarium of metal, plastic and bio-degradable stents; all having different structures and roles. This article provides an overview of the currently available stents and their recommended use in various oesophageal diseases. Although the ideal stent is yet to be developed, its elements have been identified and the future holds promise. References 1. Leroy, d’Etiolles. In De lavacherie de I’oesophagotomie. Brussels, 1845. 2. Low D, Kozarek RA. Esophageal endoscopy, dilation, and intraesophageal prosthetic devices. in Hill L, Kozarek RA (eds): The Esophagus Medical and Surgical Management. Philadelphia, PA, WB Saunders, 1988. 3. Celestin, LR. Permanent intubation in inoperable cancer of the oesophagus and cardia. Ann Roy Col Surg Engl 1959;25:165. 4. Torek, F. The first successful resection of the thoracic portion of the esophagus for carcinoma: preliminary report. JAMA 1913;60(20):1533. doi:10.1001/jama.1913.04340200023008 5. Procter, DSC. Esophageal intubation for carcinoma of the esophagus. World J Surg. 1980;4:451–460. doi.org/10.1007/ BF02393173 6. Liakakos TK, Ohri SK, et al. Palliative intubation for dysphagia in patients with carcinoma of the esophagus. Ann Thorac Surg 1992;53(3):460-463. REVIEW