Introduction
Those identical, ethical mandates were told to me on two occasions: first, when as a preteen I objected to my father, a dentist, fluoridating the teeth of his young patients, suggesting that he was sacrificing his income (and my future college tuition) by the prevention of caries; second, when as a proto-lithologist, Michael Grasso and I discussed the founding of a kidney stone clinic and I asked Michael if he was worried that I would reduce the number of ureteroscopies and lithotripsies he would perform.
Kidney stones are common and preventable, but not commonly prevented. Instead, our experience has been that most patients, despite their interest, have not received any serious recommendations about how to avoid kidney stone recurrence. Stone formers seek advice regarding their disorder, whether that is about the choices for urological intervention or strategies and regimens for prevention. Bringing these two components of kidney stone practice together into a single setting is the goal of a kidney stone clinic.
Like any other disorder, expertise among practitioners develops with exposure and repetition. A kidney stone clinic offers these assets to its personnel while offering patients the confidence that develops when expertise is demonstrated. Simply titling one's office or practice a “kidney stone clinic” may lead to some assurance that the disorder is seen repeatedly there, but developing a real integration of diverse skills and mastery will be even more convincing.
This book arises from the partnership that Michael Grasso and I began in 1996 when we first formed a kidney stone clinic. Michael brought his vast experience in endourology and urological intervention for kidney stones to our enterprise. My contribution, as a nephrologist and physiologist, was to specialize in the metabolic evaluation and prevention of stone disease. Thousands of patients later, we have exchanged enormous amounts of information and experience, so that our patients can be certain that together we can approach any problem related to nephrolithiasis.
The urological management of kidney stones is extensively described elsewhere in this book. In this chapter I will focus on the other components of a kidney stone clinic. There are some data regarding the performance of a kidney stone clinic but inevitably what I write here includes much opinion.
Personnel
The kidney stone clinic starts with a urologist interested in kidney stones. That urologist may be an endourologist with further postresidency training in the appropriate techniques but in many settings, such a subspecialist may not be available. No matter. Patients with stones are referred to urologists first, and infrequently to nephrologists or internists. In a smaller community where an endourologist is not available, a general urologist presumably has ample experience in the management of most stones, perhaps referring to an endourologist in only more complex cases. Referral may be appropriate for larger stones, stones associated with infection, cystine stones, and anatomically abnormal or solitary kidneys.
There are urologists who can constitute a kidney stone clinic by themselves, with no other personnel required. Such urologists are widely knowledgeable about urine chemistry and how to modify it and reduce stone recurrence risk with diet and medications. They are happy to discuss the relevant variables with their patients and answer questions about appropriate preventive regimens. There are also urologists who understandably are less interested in performing such duties. After all, urology residency training often does not emphasize such skills. Compensation for urologists has a procedure-based emphasis which necessitates a shorter office visit that may not lead interested patients to feel that their concerns have been adequately addressed.
In that case, the addition of a nephrologist or internist makes an important contribution to the prevention component of a kidney stone clinic. This person, interpreting results of diagnostic tests and prescribing dietary modification or medications, does not have to be a nephrologist. An internist can learn the syllabus quickly, as internists have been trained to pay attention to these sorts of preventive modalities. In recent years, we have had a general internist doing kidney stone prevention at Bellevue Hospital, a large public facility in New York City. Two general internists oriented towards preventive care, in consultation with me, learned the field, recognizing it as similar to addressing cardiovascular risk factors. The frequency of a clinic’s occurrence can be variable and obviously would depend on the volume of appropriate cases. Even a monthly clinic would offer an important service.
I note, however, that a nephrologist or internist will not easily constitute a kidney stone clinic without the involvement or endorsement of a urologist. In my experience, it takes a long while before any volume of referrals can come from anyone other than the kidney stone clinic's urologist. First, kidney stones are often not given the serious attention they deserve; family practitioners and general internists may not recognize that any preventive regimen is appropriate until significant recurrences have occurred. Second, as stated previously, most patients are seen only by urologists, who, if not specializing in stone treatment, may give prevention little heed and are unwilling to refer their patients to specialists outside their own practice. Third, most patients are unaware that anyone specializes in kidney stone prevention and find a kidney stone clinic only after the frustration of recurrence. And fourth, while most nephrologists also have little to no training in stone prevention during their fellowships, they dabble in the field and are also reluctant to give to their patients another nephrologist's name. I therefore think that a kidney stone clinic must be based on the keystone of a high-volume endourologist.
The kidney stone clinic's nephrologist or internist cannot perform procedures, but can become expert in diagnosing and managing renal colic and knowing when referral to the urologist is appropriate. He or she can also be useful and offer a second opinion to patients deciding about treatment of symptomatic or asymptomatic stones, and in choosing between urological interventions. In addition, patients with kidney stones have a host of co-morbidities including diabetes, hypertension, gout, coronary artery disease and chronic kidney disease, all of which can be favorably influenced by the involvement of an internist. Urologists may be less at ease treating such patients, dealing with underlying electrolyte disturbances or those resulting from prescribed medications and changes in kidney function that result from obstruction and its reversal. While the prevalence of chronic kidney disease in the average endourology practice has not been quantified, a nephrologist can offer a different, medical perspective to such patients, addressing mineral and bone disorders, osteoporosis, hyperparathyroidism, kidney transplants, resistant hypertension and, rarely, management of and preparation for end-stage kidney disease.
It is highly desirable to have a dietician as part of the program [1]. Patients seek dietary advice, which often is confusing. Dietary prescriptions are preferable particularly for younger people who often are more reluctant than older adults to take medications like citrate supplements or thiazides. Older people often have co-morbidities such as diabetes and cardiovascular disease and feel they have “nothing left to eat” when vegetables like spinach, which they considered “healthy,” turn out to be high in oxalate.
Dieticians are most likely to be accessible in a university or Department of Veterans Affairs setting because many health insurers in the United States will not pay adequately for visits with dieticians. In such cases, patients may be reluctant to pay for s...
