"By prevailing over all obstacles and distractions, one may unfailingly arrive at his chosen goal." Christopher Columbus (1451-1506)

Endoscopic retrograde cholangiopancreatography (ERCP) remains the gold standard for the diagnosis and treatment of biliopancreatic disorders, and over one million ERCP procedures are performed each year worldwide. ERCP has always been performed by a group of courageous endoscopists who on a daily basis managed to develop its full diagnostic and therapeutic potential over the technique's 50 years of lifespan, always making the most of radiographic images, ever secretly dreaming of directly viewing the banned, consigned-to-oblivion territory. Except, indeed, when this group of Spartans was required to go in the dark through the gates of Troy, using their long-acquired skills, and assuming the all-pervading risks of their raid. Well, the dream is now starting to come true. Finally, we may leave our "aspides and dories" behind, replacing them by "drones and lasers."

Although a fully developed technique, ERCP has two major weaknesses. First, it cannot provide information on mucosal lesions not protruding in the lumen of the biliary tract. Consequently, positive results from sampling boil down to 20-30% for isolated exfoliative cytology, and to 50% when cytology may be combined with brushing and biopsy 1,2.

Initial attempts at gaining visual information from bile ducts date back to the early 1960s as a surgery-supportive diagnostic system 3, and it was not until 1976 and 1977 that initial reports appeared on cholangioscopy, whether direct 5 or with the aid of a duodenoscope 4. We needed to see to believe; above all, we needed to see to know.

Today, ultrathin endoscopes provide all the imaging technology available in modern endoscopy systems, including not only high-definition cameras but also image-enhancing systems such as NBI 6 or i-SCAN 7. These may improve results in the diagnosis of malignant lesions and their extent, which leads to a different therapeutic approach in these patients. The results of these "optical" biopsies are impressive: sensitivity is 97% and specificity 93%, with a positive predictive value of 90% and a negative predictive value of 98%. We saw, and we believed, but this did not suffice for us.

Furthermore, mother-daughter systems evolved initially to allow single-operator use, and then to include digital cameras, which have notably improved image quality. So much so that current users, as Dr. Pons et al. 9, use the term "legacy" to refer to the older fiber optic system, even though most of their cases (80%) derive from its use.

All the procedures in the study by Dr. Pons 9 in this issue of The Spanish Journal of Gastroenterology (Revista Española de Enfermedades Digestivas) were performed to play a role in the diagnosis of patients with complex biliary strictures, or to treat individuals with difficult bile stones. Their results were excellent, and fully comparable with those previously reported, with success rates around 90%.

How do we define success? For indeterminate strictures success involves adequate stricture visualization wherever its location within the biliary tree. With this system we may reach the second branching of intrahepatic ducts; from this point on, access is more dependent on duct diameter and anatomic layout. This is why sensitivity remains near 90%, and the proportion of appropriately directed biopsies is limited to 80% in reported series 10,11. A pertinent question here may be: why is sensitivity higher for optical biopsies? The answer lies in the ability to assess the area's microvasculature. In contrast, the proportion of false positive results is distinctly lower for directed biopsies, a fact that both surgeons and oncologists, and most particularly patients, ultimately appreciate.

We saw, believed, and knew, but that still was not enough. We are physicians. Our primary goal is curing, and there lay our major enemy in the biliary tract: that 15% of difficult-to-manage bile duct stones. Although cholangioscopy does not allow us to modify patient characteristics or anatomy, it does render accessible to endoscopic treatment multiple or large stones, stones lodged in intrahepatic ducts, and stones located beyond a stricture. Results are once again amazing: in over 80% of cases, the biliary tract may be effectively cleared, as elegantly demonstrate the results obtained by Pons et al. 9,11,12.

Although the results obtained by sphincteroplasty in the removal of large stones leave intraductal lithotripsy with cholangioscope, whether a mother-daughter system or an ultrathin endoscope, as a rescue option 13, in cases where papillary dilation magnitude is not the answer (distal stones, stricture, diameter disparity) cholangioscopy-guided lithotripsy undoubtedly remains not only the first option but also the single alternative to surgery.

Furthermore, cholangioscopy has been shown to be not only effective but also cost-effective for the diagnosis of complex strictures and difficult bile duct stones, with a reduction in overall costs of 5% to 11% 14 despite the high cost of the system's disposable items, above 3,500.00 (including biopsy forceps). A reflection here is that the price of an ultrathin endoscope is around 15,000.00, that is, that by saving the cost of five cholangioscopies using the SpyGlass(tm) system we could purchase an ultrathin endoscope, which in addition to providing high-resolution images has multiple other uses in daily endoscopy practice. However, the odds of reaching the intrahepatic biliary tract are reduced particularly in a stable position.

All in all, these good results merely open up a range of future therapeutic opportunities including: selective cannulation 15, hemostasis 16, radiofrequency application, lesion resection 17, and removal of foreign bodies 18 (migrated stents and retained drains). For this is our ultimate goal: seeing to cure.

Let me finish now by picking up again my initial metaphor. Spartans! We are ready!

Let us be grateful to all those who suffered unending learning curves, frustration from failed or incomplete procedures, and lawsuits in the dark ages of unaided ERCP. Now we can see our enemies, and have weapons to defeat them.

Spartans! Ahoo! Ahoo! Ahoo!

BIBLIOGRAFÍA

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