Advances in therapeutic endoscopy

AdvAnces in endoscopy

Advances in therapeutic endoscopyRajvinder singh

Krish Ragunath

AbstractThere have been significant advances in gastrointestinal endoscopy.

developments in endoscopic technology suggest that even greater

achievements in diagnosing and treating gastrointestinal disorders will

be possible. This review focuses on the recent developments in the field

of therapeutic endoscopy.

Keywords ablative therapy; endoscopic mucosal resection; enteral

nutrition; gastrointestinal bleeding; luminal stenting; therapeutic

endoscopy

Gastrointestinal bleeding

Endoscopic therapy has been shown to decrease mortality and morbidity in patients presenting with gastrointestinal (GI) bleed-ing. The Rockall score is a useful clinical grading system in acute non-variceal bleeding that predicts the risk of mortality based on various independent variables (age, shock, co-morbidity, endos-copy findings) hence allowing patients to be stratified into high or low-risk groups.1 It cannot be stressed enough that aggres-sive intravenous resuscitation with fluids and blood, and airway protection is crucial in the management of an acutely bleeding patient be it from a variceal or non-variceal source prior to any endoscopic intervention.

A number of hemostatic endoscopic methods have been devel-oped to tackle non-variceal bleeds. Injection therapy (adrenaline 1:10,000 dilution), thermal devices and endoclips are generally used in combination. These modalities have been used over the last decade with minor modifications allowing better access and accurate placement. The amalgamation of dual therapeutic

Rajvinder Singh MRCP is Consultant Gastroenterologist at the Kuala

Lumpur General Hospital, Malaysia, and is currently attached to

the Wolfson Digestive Diseases Centre, Queen’s Medical Centre,

Nottingham, UK as an Endoscopy Fellow. Having been awarded the

prestigious Lancet International Fellowship 2006, he is pursuing

an MPhil in Advanced Endoscopy Imaging at the University of

Nottingham. Competing interests: none declared.

Krish Ragunath DNB MPhil FRCP is Associate Professor in Endoscopy

and Consultant Gastroenterologist at the Wolfson Digestive Diseases

Centre, Queen’s Medical Centre campus, Nottingham University

Hospitals NHS Trust, UK. He has a special interest in Barrett’s

oesophagus, advanced endoscopic imaging and therapeutic

endoscopy. Competing interests: none declared.

Medicine 35:6 33

modalities into a single device allows for quicker haemostasis. This has been demonstrated by the incorporation of the water jet channel into the heater probe and the combination of the injection needle with the bipolar cautery. The introduction of two- and three-pronged clipping devices makes it possible to better grasp a bleeding vessel (Figure 1). Some newer clips allow the endoscopist to open, close and rotate the clip on demand to the desired axis facilitating better placement and reducing the number of clips needed to achieve haemostasis. Argon Plasma Coagulation (APC) is especially effective in ablating angiodys-plastic lesions (Figure 2).2 High-frequency monopolar current is applied in a non-contact manner with argon acting as a conduc-tor. This leads to coagulation of the superficial vessels up to a depth of 3 mm.

Tissue glue, isobutyl-2-cyanoacrylate, mixed with lipiodol is effective in bleeding from gastric varices which previously required emergency salvage surgery or transjugular intrahepatic portosystemic shunt (TIPSS).3

Double-channel therapeutic endoscopes have been intro-duced for better management of upper GI bleeding. Advantages include the ability to suction greater quantities of blood and to use two devices simultaneously. In addition, these endo-scopes have an accessory irrigation channel that can provide a high-intensity water jet when connected to an irrigation pump, thereby allowing better visualization of a bleeding vessel. It also has a bridge distally, which allows elevation of the hae-mostatic device for better approach, angulation and targeted therapy.

Despite introduction of these devices, GI bleeding some-times cannot be controlled endoscopically. Endoscopic appear-ances of bleeding ulcers are useful in predicting rebleeding risks. Patients with a spurting artery or an oozing vessel have a rebleeding rate from 55–90%.4 Ten to 15% of patients with a variceal bleed will continue to bleed despite initial medical and endoscopic therapy. It is especially important for the endos-copist to recognize this and it is prudent to consider radio-logical or surgical interventions rather than further endoscopic intervention.

Endoscopic mucosal resection

This technique has increasingly come to the fore as a minimally invasive procedure to address dysplastic or superficial neoplas-tic lesions of the gastro-intestinal tract.5 Lesions deemed suit-able for endoscopic mucosal resection (EMR) are lifted with submucosal injections of a fluid cushion before application of variously sized snares or caps for removal. Piecemeal resec-tions are performed for lesions larger than 10 mm. However this can be technically difficult and sometimes leads to incomplete removal. To obviate this, endoscopic submucosal dissection (ESD) has been introduced recently. This allows en bloc resec-tion of large flat dysplastic lesions in a single piece using vari-ous knives (flex, needle, hook, insulated tip and triangular tip) designed to allow the endoscopist to dissect the lesion in a free-hand manner (Figure 3). Resected specimens can be accurately staged and further management tailored to the histology. The main complications of these procedures include perforation and bleeding, hence they are generally performed in ‘high-volume expert’ centres.

3 © 2007 published by elsevier Ltd.


Hemoclip application. Bleeding visible vessel after adrenaline injection followed by application of three hemoclips.

Figure 1

Luminal stenting

The development of self-expanding stents now allows pallia-tion of malignant strictures in patients with advanced cancers unsuitable for surgery.6 These stents have been used in the oesophagus, duodenum and the colon with good effect. The basic feature is their ability to be captured on a delivery sys-tem to a smaller diameter facilitating placement across the stenosed region. After release, the stent expands to reach its original shape. Covered stents have also been introduced to prevent tumour ingrowth and in cases of tracheo-oesophageal fistulae.

Newer generation oesophageal stents with an anti-reflux device located at the tip can be placed in patients with lower oesophageal/cardia tumours. This can prevent reflux-related symptoms post-procedure. Complications of endoluminal stent-ing would include re-obstruction of tumour due to ingrowth and overgrowth, migration of the stent, perforation and bleeding. Recently, the development of self-expanding plastic stents which

Medicine 35:6 33

are removable has been an important advance in the manage-ment of strictures due to benign disease.

Ablative therapies

Photodynamic therapy (PDT) allows ablation of dysplastic non-localizable lesions in the oesophagus resulting in a 50% risk reduction in the development of cancer.7 A photosensitizer is first administered, either intravenously (sodium porfimer) or orally (5- amino levulinic acid [ALA]). This is followed by photoradia-tion. About 80% of patients develop some chest pain approxi-mately 6–8 hours after the procedure which sometimes requires narcotic administration. Strictures are the most common chronic complication of PDT. Recently, advanced ablation technology using radio-frequency ablation (RFA) administered through a balloon catheter has been evaluated for treatment of dysplasia in Barrett’s oesophagus.

Superficial coagulation of remnant dysplastic lesions after incomplete or technically difficult EMR/ESD can further be

Argon plasma coagulation application to an angiodysplastic lesion in the caecum.

Figure 2



endoscopic submucosal dissection (esd). a Lesion in the gastric body, borders of which were marked with a needle knife. b esd with

insulated-tip knife. c complete resection of the tumour.

Figure 3

achieved by APC (Figure 2). APC has also been used for treating radiation proctopathy, ablating Barrett’s epithelium and pallia-tion of GI malignancy.2

Enteral nutrition

The maintenance of appropriate nutrition is well recognized as a fundamental part of optimal medical and surgical care. Enteral nutrition (EN) has been shown to shorten hospital stay as well as improving outcome by supporting the structural integrity of the gut wall and preventing bacterial transmigration.8 It is pre-ferred over parental nutrition in critically ill patients because of its relative simplicity and lower cost. EN can be delivered into the stomach or small bowel via nasogastric and nasoenteric

Medicine 35:6 33

tubes. However, this can be inconvenient to the patient and can be displaced easily. It is now possible to endoscopically place gastrostomy tubes (percutaneous endoscopic gastros-tomy: PEG) or jejunostomy (PEJ) tubes (Figure 4). These tubes can be left in situ for longer, patients can be taught to use them themselves, and they are cosmetically more acceptable. These factors are particularly useful for patients with cerebrovascular accidents or other chronic neurological disorders with swallow-ing difficulties.

Conclusion

The myriad of innovations has pushed the boundaries of gastrointestinal endoscopy over the last few decades from a

a A percutaneous endoscopic gastrostomy feeding tube and b the internal bumper.

Figure 4



purely diagnostic to a minimally invasive and cost-effective ther-apeutic tool. Already on the horizon are further developments with novel stapling and suturing devices as well as endoscopic ‘outside the lumen’ surgery. Interventional endoscopy will surely progress further and may increasingly compete with surgical procedures on a range of indications. ◆

REFEREnCEs

1 Rockall TA, Logan RF, devlin HB, northfield Tc. Risk assessment

after acute upper gastrointestinal haemorrhage. Gut 1996; 38:

16–21.

2 vargo JJ. clinical applications of the argon plasma coagulator.

Gastrointest Endosc 2004; 59: 1–8.

3 seewald s, Mendoza G, seitz U, salem o, soehendra n. variceal

bleeding and portal hypertension: has there been any progress in

the last 12 Months. Endoscopy 2003; 35: 136–44.

4 Forrest JA, Finlayson ndc, shearman dJc. endoscopy in

gastrointestinal bleeding. Lancet 1974; (ii): 394–97.

Medicine 35:6 3

5 pech o, May A, Gossner L, Rabenstein T, ell c. Management of

pre-malignant and malignant lesions by endoscopic resection.

Best Pract Res Clin Gastroenterol 2004; 18: 61–76.

6 simmons dT, Baron TH. Technology insight: enteral stenting and

new technology. Nat Clin Pract Gastroenterol Hepatol 2005;

2: 365–74.

7 Barr H, dix AJ, Kendall c, stone n. The potential role of

photodynamic therapy in the management of upper gastrointestinal

disease. Aliment Pharmacol Ther 2001; 15: 311–21.

8 Braunschweig cL, Levy p, sheean pM, Wang X. enteral compared to

parental nutrition: a meta analysis. Amer J Clin Nutrien 2001; 74:

534–42.

FuRthER REAdinG

Binmoeller KF, seifert H, schreiber HW, soehendra n. Therapeutic

endoscopy. ny, UsA: Thieme Medical, 2005.

classen M, Tytgat G, Lightdale c. Gastroenterological endoscopy.

ny, UsA: Thieme Medical, 2002.

Ginsberg GG, Kochman ML, norton id, Gostout cJ. clinical

gastrointestinal endoscopy. oxford: elsevier, 2005.


Documents

Advances in therapeutic endoscopy