In Memoriam of Henry Tenckhoff

Abstract

The whole world mourned deeply the recent passing of Dr. Henry A. Tenckhoff (Fig. 1), a giant of nephrology and dialysis. He will be sorely missed by his family and friends, his fellow healthcare professionals, and myriad renal failure patients across the continents. Dr. Henry A. Tenckhoff. [Color figure can be viewed at wileyonlinelibrary.com] Owing to the fact that we have benefitted greatly from his inventions and expertise, we are most keen to pay tribute to Dr. Tenckhoff. His contribution to the development of peritoneal dialysis (PD) has been more substantial than simply designing a catheter that enables long-term dialysis not only to take place but also to save lives. Before he made the groundbreaking catheter, he set a perfect example of patient-centered care and outreach service by visiting each and every one of his PD patients every weekend—and later twice weekly, inserting a temporary catheter and setting up the intermittent PD treatment—not to mention the amazingly low complication rate of his temporary catheter insertion. (For those who have personal experience of inserting temporary PD catheters, the difficulty of repeated insertion to the same patient does not require further elaboration.) Although treatment of this kind is far from ideal, Dr. Tenckhoff showed that infection is not inevitable 1, uremic neuropathy could be prevented 2, and nitrogen balance could be maintained in most patients 3. Notably, Dr. Tenckhoff was probably one of the first few who did the research to link dialysis adequacy and nutrition. He showed that although PD patients lost considerable amounts of protein and other macromolecules to the dialysis effluent, nitrogen balance could be maintained by increasing dietary protein intake 3—advice that we still give to our patients nowadays. His observation was further expanded by Babb and Popovich to become the middle-molecule hypothesis and form the basis of continuous ambulatory peritoneal dialysis 4. As to his masterpiece, Dr. Tenckhoff made a perfect demonstration of the motto details make the difference. He tested different materials for the cuff, moved from single to double cuff design, tried straight, and curled catheters, experimented with side-holes of various sizes, fixed the length of the subcutaneous tunnel, suggested the optimal distance between the skin and external cuff, confirmed the role of the radio-opaque stripe, and pioneered the insertion trocar (which was patented, and the monetary gain used to support further PD research). The success of the Tenckhoff catheter is no doubt the single most important step that enables PD to become a realistic long-term replacement therapy. With such a brilliant original, subsequent designs (e.g., subcutaneous burying and presternal catheter 5-7) appear novel but nonetheless modifications. It comes without surprise, therefore, that no subsequent catheter design has been shown to further reduce the risk of catheter-related infections or peritonitis 8, 9. The implication that Dr. Tenckhoff himself designed and inserted the very first permanent PD catheter is subtle but profound—as he was a nephrologist. In the following decades, most PD catheters around the world were inserted by surgeons, urologists, or interventional radiologists. It was only in recent years that the enthusiasm of inserting PD catheters by nephrologists resurged. In addition to the well-known advantages of insertion by nephrologists (including timely insertion of the catheter and better appreciation of the patients’ need 10, 11), we should remind ourselves this practice is the traditional standard rather than, as it now often appears, an exception. There are, of course, other influential research contributions made by Dr. Tenckhoff. For example, he designed a home-based system of water purification that aimed to make PD solution on site 12, 13. Although the system is not in wide clinical use nowadays, it was not only ahead of its own time, but had considerable influence on the subsequent development of water treatment devices used for home hemodialysis. In 1995, when one of us performed his first PD catheter insertion on a patient (under the supervision of a senior urologist), he looked at the catheter, which was the traditional straight double-cuff Tenckhoff (Fig. 2), amazed with its simple but flawless design, exclaimed, “This is really the U-2 of peritoneal dialysis!” For those who are not familiar with military aircrafts, Lockheed U-2 Dragon Lady is an ultrahigh altitude reconnaissance aircraft of the US Air Force that was first introduced in 1957 and, because of its brilliant design and unsurpassable capability, remains in active use today. Ironically, the role of the U-2 aircraft is slowly passing over, not to any better designed reconnaissance aircraft, but to satellites. Similarly, we believe that the present significant role played by the Tenckhoff catheter would eventually be diminished, not by any better catheter, but only by the ascendancy of the allograft or the artificial kidney. Nevertheless, in patients who are not suitable candidates for renal transplantation and in those other patients who have exhausted their vessel sites for access construction, peritoneal dialysis using the irreplaceable Tenckhoff catheter will still be the treatment of choice. Indeed, from what the world has learned about the Tenckhoff catheter over the years, we predict that this marvelous device will stand the test of time and continue to provide benefit to humankind for a long time to come! The original double-cuff straight Tenckhoff catheter. [Color figure can be viewed at wileyonlinelibrary.com] Like theologists say, we do not have to see something before believing, and we do not need to meet someone before admiring. As practicing nephrologists, we have the luxury of looking far because we are standing on the shoulders of giants—and we find the shoulders of Dr. Tenckhoff safe and secure; his legacy timeless and immortal.