Black and white amid the colors of endoscopy – the march of endoscopic ultrasonography

In 1984, the 16th year of existence of the journal Endoscopy (now 50 years old), a first article was published on a previously unknown endoscopic technique called “endoscopic ultrasonography” [1]. Although the technique of endoscopy was still quite rudimentary, using instruments completely unlike the current ones, the Olympus Company from Tokyo, Japan had developed the first prototype series of echo-endoscopes, which they called GF-UM1, “GF” standing for “gastro-fiberoptic” and “UM” for “ultrasound mechanical.” The first small series of the GF-UM1 had been distributed to the leading endoscopy centers around the world in order to gain experience and insight into the potential of this new technique. Dr. Lok Tio was a gastroenterologist with considerable experience in abdominal ultrasonography, which was considered a prerequisite at that time. At the time of this publication he worked in the brand-new Academic Medical Center (AMC) in Amsterdam under the leadership of Professor Guido Tytgat, in a relatively small department with five gastroenterologists and four trainees. Dr. Tio had decided to devote his career to this novel technique and spent every day of the week in understanding and further developing the new modality. It is probably important to realize that in the early 1980 s, 35 years ago, the investigation of the gastrointestinal organs was also in its early phases. The main techniques were X-ray investigations with barium of the upper or lower gastrointestinal tract. Ultrasonography was available but lacked penetration and computed tomography had only recently been introduced. This was still a time when many laparotomies were performed every day as a purely diagnostic technique and all endoscopies were also mostly diagnostic, serving as guidance to surgical intervention.

The article “Endoscopic ultrasonography in the assessment of intra- and transmural infiltration of tumours in the oesophagus, stomach and papilla of Vater and in the detection of extraoesophageal lesions” by Tio & Tytgat describes the first series of patients who had been investigated at the AMC. It reports the findings in 11 patients with esophageal cancer, 4 with extraesophageal lesions, 6 with gastric cancers, and 5 with papilla of Vater cancers, that had all been “thoroughly investigated.” A second part of this scientific work was done in autopsy material, aiming to understand the visualized layer pattern of the stomach and to characterize the individual layers by investigating the specimens repeatedly after scraping off the individual layers.

The GF-UM1 instrument had an outer diameter of 13 mm and a rigid tip 45 mm in length. The authors describe that it was especially difficult to pass the pylorus and consequently it was even harder to reach the second part of the duodenum. Fortunately, no complications were reported. The article is replete with black and white illustrations; these clearly show what we can still visualize with our current instruments but nowadays with much higher resolution and penetration. The five tables in the article are charmingly simple in that they just present columns for each of the different available imaging techniques including EUS, and score whether or not the lesions were visible with each technique using a plus, a minus or “not performed” symbol. This is really one of the very basic first descriptions of the technique by two of the pioneers.

Tio & Tytgat’s article was followed three years later by an editorial in The Lancet that described EUS as a “marriage of inconvenience” which, in the opinion of the anonymous author, would be “best restricted to research centers” [2]. But history proved that author to be wrong and EUS developed slowly but steadily into the important diagnostic and interventional technique that is now available in most hospitals in Europe. Interestingly enough, the rapid developments of noninvasive imaging techniques such as CT, MRI and, to a lesser extent, abdominal ultrasonography have restricted the indications for EUS as a diagnostic tool and EUS has increasingly become a tool for obtaining pathology samples as well as for therapeutic interventions. For certain indications, such as the esophagogastric cancer staging pioneered in the article, however, EUS is still an important technique and has substantial impact in stratification of patients to identify who would benefit most from neoadjuvant therapy. Unfortunately, the technique has not been developed further in the last 10 – 15 years (e. g. in parallel with the possibilities of transabdominal ultrasound), but this should definitely be reconsidered.

After the radial scanning equipment described by Tio and Tytgat, new linear instruments were developed, first by Pentax and later also by Olympus and other manufacturers. The linear equipment allowed the real-time visualization of cytological and later histological needles, first described in the literature in English by Vilmann et al., again in Endoscopy [3]. But even more interestingly, this possibility had already been mentioned in the 1984 article. So, the circle closes to memorialize those who were pioneers and to send our congratulations to Endoscopy, a journal that gave room to many of the first descriptions of novel endoscopic techniques, illustrating the power of European innovations in endoscopy!

Fig. 1 Diagnostic endoscopic ultrasound (EUS). a EUS came to revolutionize endoscopy as it added the ability to visualize beyond the luminal gastrointestinal tract and it’s surroundings. By using fine needle aspiration of suspected lesions the diagnostic yield of EUS markedly increases. b Both radial and linear EUS scopes have specific applications. Radial EUS is ideal to define lesions located within the layers of the gastrointestinal tract, whereas linear EUS is quite useful to evaluate the pancreatibiliary tract. c Linear EUS image depicting a dilated bile duct with stones inside (choledocolithiasis). Source for Fig. 1c: Klaus Mönkemüller. Illustration: Michal Rössler

• References

• 1 Tio TL, Tytgat GN. Endoscopic ultrasonography in the assessment of intra- and transmural infiltration of tumours in the oesophagus, stomach and papilla of Vater and in the detection of extraoesophageal lesions. Endoscopy 1984; 16: 203-210
• 2 Endoscopic ultrasound – a marriage of inconvenience?. Lancet 1987; 2: 431-432
• 3 Vilmann P, Hancke S, Henriksen FW. et al. Endosonographically-guided fine needle aspiration biopsy of malignant lesions in the upper gastrointestinal tract. Endoscopy 1993; 25: 523-527