Friday, 11 October 2013

The magical “floating” kidney

I started writing this up as a “Lesson from History”, because floating kidney (or “nephroptosis”) was big in the late 19th century, and I thought that the condition was no longer taken seriously. In researching this however, I found that surgery for this condition is having a resurgence thanks to laparoscopic (keyhole) surgery. To a man with a hammer, everything looks like a nail.

This review of floating kidney from 1997 tells us that this diagnosis was once very common, and that there have been nearly 200 different operations described since the late 1800s including removal of the kidney, but most of the operations are forms of nephropexy (tying down the kidney). At the end of the 19th century, surgery for floating kidney was the most common procedure performed by urologists.

Floating kidney has been associated with multiple causes, and blamed for wide variety of symptoms (including symptoms from damage to surrounding organs, nervous weakness, urinary tract infections, depression and irritability), and the condition has been described as being present in up to 20% of people without symptoms.

This report from 2001 of a series of patients treated with nephropexy noted the following symptoms:

Are we expected to believe that this questionable condition is capable of causing all of these symptoms? Hypertension (high blood pressure)? I am surprised that only one patient had hypertension, given how common it is.

Floating kidney was initially diagnosed by feeling the abdomen, but with more modern imaging, movement of the kidney has been detected by dye injections, CT scans, Doppler imaging and bone scans. The diagnostic criteria have been tightened (more than 5cm movement of the kidney between lying down and sitting) as have the classification of the condition and the indications for surgery. The diagnostic criteria have been set without any reference to how much a kidney normally moves, and without any correlation with symptoms.

Surgery for floating kidney (nephropexy) has always been controversial, with one early critic commenting that the biggest complication of nephroptosis (floating kidney) is surgery. Even at its peak, there were skeptic urologists who denied the condition existed. Surgery was not the only treatment though, with good relief being demonstrated with the use of various corsets that push the kidney upwards.

Controversy (and the high complication rate from surgery) led to a decline in the diagnosis and treatment of this condition after the 1920s. Since the 1990s however, there have been many reports of nephropexy being done laparoscopically.

The evidence
This review from 2008, like the 1997 review, notes the reappearance of the diagnosis of nephroptosis, and suggests that better diagnostic criteria, along with minimally invasive techniques, allows surgical correction to be performed in selected patients. The authors note that despite any comparative studies and a lack of standardisation of the surgery, laparoscopic [keyhole] nephropexy “will remain the standard therapy”. The 2008 review (along with another review from 2004, and other recent reports, including one using robots) describe “clearly” favourable results from surgery. I don’t buy it, for two reasons.

1. The diagnosis
The diagnosis has never been established. I hear about movement, impaired kidney function, blocked flow, blood in the urine, and a myriad of “classical” symptoms, but nothing has been produced that reliably attributes any symptoms to a kidney that moves more than 5cm. We need to see a study showing that symptoms (whichever ones we choose) are more common in people whose kidneys move >5cm than those whose kidneys move <5cm.

2. The treatment
The treatment has never been validated. I’m not even talking about placebo RCTs; any comparative study would satisfy me for this particular topic. Compare it to psychological counselling or chiropractic for all I care, but compare it to something, otherwise we don’t know if the patients got better as a result of the surgery or not. And what about the abnormal kidney function? That made it sound serious, but they didn’t even test it post-operatively, so we don’t know if there was any improvement. Most of the time, we don’t even know if the kidney stopped ‘floating’. Doing a handful of cases and saying that most of the patients felt better afterwards just doesn’t cut it science-wise (although it is good enough for most surgeons).

Then how do I explain the (roughly) 90% favourable results? Firstly, I don’t even know how “favourable” is defined or what is being measured, but either way, the answer is the same: most people (particularly those with vague symptoms and no clear diagnosis) get better after any treatment, just ask the homeopaths.

Diagnosis of convenience?
It is quite possible that patients with non-specific low back pain and lumbar pain are being diagnosed with this condition by virtue of the fact that they are sitting in the urologist’s office at the time. The same patient in a spine surgeon’s office might have had been given a spinal diagnosis. If you don’t believe that doctors fit patients into their own paradigm (i.e. diagnose what they are familiar with) then read this blog post.

The bottom line
This is a great example of the how myths spread through a supposedly scientific community. Once a procedure has been done enough times and published, it is accepted as reasonable. Then all you need to do is keep changing (“tightening”) the criteria for diagnosis and treatment (to explain any bad results from "the old" technique), and keep reporting “favourable” results from patients in non-comparative studies. Easy.

PS: Before any urologists misinterpret this article and start commenting, please note that I am not criticising urologists or urology in general. This is an example of what happens in many fields of medicine. I expect that most urologists do not consider this a valid diagnosis or treatment, but there are clearly some who do.


  1. FWIW, several years back, I noticed a firm mass in my LUQ which US confirmed was my kidney. The right one followed suit (presumably, as I didn't bother with US again) a couple of years later. No symptoms. Oddly, to me at least, they seem to have headed back to their previous location during pregnancy, and stayed put the last few years. No nephropexy for me ;)

  2. You dont buy it? That is very unfortunate for your patients. Says a patient who had 2 floating kidneys and symptoms more extensive than your abbreviated list -and which caused complete legal and physical disability-all gone with nephropexy and I can now function normally and have returned to full time work and life.

  3. Also, my symptoms were clearly demonstrated to be irrefutably caused by the dropped kidneys-prior to surgery. The problem is with the lack of appropriate testing, not the diagnosis.

    1. I am sure that many of the patients who had surgery back when nephropexy was the most popular operation in urology also improved after surgery. I also reckon that they were told that their symptoms were "irrefutably caused" by the dropped kidneys. I have trouble irrefutably proving any causation in medicine, let alone this one. There is a big gap between association and causation.
      For most of the treatments I list in this blog, about 70% of patients get better after the treatment, even when the treatment has been shown to be no better than placebo. I accept that people get better after (almost any) treatment, even treatment that cannot possibly work, like homeopathy. But for all your widespread symptoms and legal and physical disability to be completely resolved from stitching down your kidney is, to me, drawing a very long causation bow.

  4. When all of the information gleaned from the first nephopexy done in 1881 and a physician is willing to listen to that information and re interpret much of it in todays medical terminology, the bow is in fact quite short.

    Had I not had a physician willing tp think outside the proverbial box and actually run a test that was not only probably contraindicated but almost irresponsible in its irrelevancy by all commonly acceptable standards -and certainly disputed by all insurances-for the 'presenting symptoms', and even if only to disprove it based on its obscurity, I would have languished for the rest of my -most likely shortened-life in a horizontal hell.

    I must disagree though that 70% percent of patients improve regardless of the appropriateness of treatment. I would surmise that many cowtow to the agreement and either give up or agree in order to appease and seek treatment elsewhere. Unfortunately, due to the abitlity of most current physicians to think in a manner not commonly 'taught' often gets patients nowhere except frustrated, defeated and falling into the wonders of the dsm where of course 70% of patients 'improve'. And in no way am i placing the entire fault on physicians. I believe there is an inherent and possibly intentional flaw in the teaching methods, materials, and intentions for the direction modern medicine is taking.

    To clarify my statement referring to 'irrefutably caused' and symptoms, i will mention that many tests were preformed in supine and standing positions which did indeed show irrefutable causation, not merely association. If you would like to post -or forward in some manner-contact information, I would be very happy to elaborate... because unfortunately:

    Patients and physicians are being denied knowledge, options and treatment, information, and in all likelyhood more cost effective and timely treatment due to the ingrained nature of the specialty boxes and flawed instruction common in today's medicine.

    1. But if the kidney normally moves up and down when we go from the supine to the erect position, how can the observation of that movement be proven to be the cause of your extensive pain and disability? Many things happen to the body when changed form supine to erect. To observe only one of those changes (kidney movement), and attribute that to widespread symptoms and function loss is your hypothesis, not your proof. Improvement with nephropexy supports your hypothesis, but that does not make it irrefutable.
      There are many people with your conviction, who vehemently believe that Treatment X cured them. They are not necessarily all wrong, and you may be one of the ones whose belief is true. However, proof of nephropexy's effectiveness will take more than individual testimonials. If we relied on anecdotal evidence to guide treatment, we would be doing even more unnecessary treatment than we already are.

  5. And food for thought... if 70% of patients are effectively 'cured' by treatments with no proven causation, what sham, quackery, and snake oil are patients AND physicians prey to in this modern medical model...and by whos hands?

  6. Unfortunately, and most likely due to this forum-my statements about irrefutable proof are either being misunderstood or disbelieved. Either way, again due to the forum, that is understandable. However, the testing that was done did not only support the causation, it irrefutably and scientifically proved it. As i stated previously, the problem is in the lack of appropriate testing. Whether that be by the lack of insight or knowledge on the physicians part, the lack of availability at the facility the patient presents in, or the lack of insurance approval or a combination of any or all, the end all be all proof is-as im sure you will agree-in the scientific proof gleaned from appropriate testing. Which thankfully, i had done. Based on your responses and initial posting, i am quite sure that you-as would most other modern physicians- be quite amazed at the systemic havoc a kidney can cause when it moves more that the average kidney should or is expected to move beyond what is structurally appropriate from the supine to standing positions. Testimonials and beliefs aside, the proof is in the pudding(scientifically proven tests) so to speak... And i agree that anecdotal evidence is often if not always innapropriate to rely on, thankfully there is nothing anecdotal about this.

  7. I had chronic back pain for about 12 years, saw several doctors and chiropractors, and never got relief until I saw a Sacro Occipital Technique chiropractor who found I had a descended or "floating" kidney. I'm only still web searching the condition, because when I am unable to see my chiropractor, and do something to pop it out of place, I wish I could figure out how to put it back myself. I would see a "doctor" doctor to see about having it tied up or taken out, but I know I will meet with a bunch of more BS because they won't believe it's my kidney.

    1. I would like to know how the chiropractor relieved your symptoms. How reliably can you attribute the improvement in your condition to and stabilisation of your kidney? Many people report relief from chiropractic treatment for a variety of conditions, but the ability of these treatments to address specific pathology (and not just leave you feeling better) is questionable.

  8. Hello! I have nephroptosis. In your opinion, is it true that laparoscopic nephropexy is not so successful as an open approach is? That's what my doctor said to me (according to him- it's because I'm from Serbia and clinics in our country don't have state of the art technology...) and because of that I decided not to go to surgery, but I have horrible pains and recurring infections...

    1. To me, the question is not so much what technique is used for the surgery, it is whether or not the surgery will improve your symptoms, and whether your symptoms are caused by (not associated with, but caused by) the position of your kidney on a scan.
      I don't know, but I doubt it - I think it is a big assumption without much supporting evidence.

  9. Well mine is floating and I have severe pain when upright, Blood in urine and renal scan shows kink in the ureter and a bit of hydronephrosis..I am a believer..hope to have surgery soon.