Half-way through the 20th century, nephrologists were responsible for numerous milestones, leading us to modern nephrology as we know it today. Nephrologists have designed and developed instruments that are fundamental for our speciality, such as renal biopsy,1 the first haemodialysis shunt,2 double lumen catheters,3 the first arteriovenous fistula for haemodialysis,4 the first tunnelled catheter for peritoneal dialysis,5 and laparoscopic catheter placing.6 Furthermore, Dr J Holmes, considered the father of diagnostic ultrasound,7 was also a nephrologist.
However, as dialysis treatment progressed, nephrologists stopped performing interventions on their patients, to the advantage of other specialities (surgeons and radiologists, mainly) yet to the detriment of overall patient care. A clear example is the significant increase in the number of patients that received dialysis through a permanent catheter or a synthetic bypass, compared with those that have received an arteriovenous fistula, during recent decades.8
Kidney patient care was therefore fragmented, being placed into the hands of other specialists, who did not fully understand the reality of kidney diseases. Furthermore, as reported by O’Neill,9 we nephrologists started to spend more time on the telephone, asking for tests, than solving our patients’ problems.
In 2000, a group of American nephrologists, aware of this controversial situation, decided to create the American Society of Diagnostic and Interventional Nephrology (ASDIN)10 so as to defeat the apathy that had developed. Its objective was for nephrologists to regain leadership, promoting the appropriate application of their techniques, that they themselves had developed, and to improve nephrology patients’ care. This Society strives to promote interventional nephrology within nephrology services and has presented an annual congress since 2005. It also has a section in the journal Seminars in Dialysis, where its original articles are published. Since 2004, the International Society of Nephrology created the Interventional Nephrology Committee with the aim of promoting and addressing issues related with this new discipline, such as healthcare provision and training.11
INTERVENTIONAL NEPHROLOGY IN THE WORLD
Diagnostic and interventional nephrology is expanding is the United States. This discipline is being included more frequently as a permanent feature of courses and congresses, such as the Annual Scientific Meeting of the American Society of Nephrology, which has been taking place since 2000.12 Hospitals offering training under this subspeciality have also increased notably in North America. However, according to a recent survey published on this matter,13 there still are not enough hospitals and even fewer are ASDIN-accredited.14-16
Interest is also growing in Latin America. Countries such as Puerto Rico, Peru, Brazil, Mexico, Colombia, Argentina and Venezuela have been incorporating interventional nephrology into their daily healthcare and in scientific meetings.17,18 The Latin American Society of Nephrology and Hypertension considers interventional nephrology as a discipline in itself and has its own interventional nephrology advisory committee.19
Europe, on the other hand, is more interested in diagnosis than intervention, i.e. introducing ultrasound to nephrology. We can assume this fact because ultrasound has featured occasionally in European Dialysis and Transplant Association pre-congress courses. However, very few studies conducted by nephrologists are presented in congresses or published in the Nephrology Dialysis and Transplantation journal.
INTERVENTIONAL NEPHROLOGY IN SPAIN
This subspeciality has hardly been developed in Spain. Although we are aware that there are numerous interventional nephrologists in Spain and that several departments boast an ultrasound machine, very few have published their experiences on performing fistula for haemodialysis,20 placing tunnelled catheters,21,22 ultrasound-guided renal biopsy,23 or peritoneal dialysis catheters.24,25 However, there are brilliant, consolidated initiatives for diagnostic ultrasound for vascular access.26
Lastly, in recent years we have learnt that kidney disease is an independent cardiovascular risk factor, and if attended to at early stages, nephrologists may have more treatment variables available, crucially influencing patient survival and quality of life. Therefore, kidney patients’ diagnosis and follow-up should not only involve examining renal anatomy, but also evaluate the cardiovascular risk, by measuring the carotid intima-media thickness, for example.27-30 This aspect is being actively researched in an important Spanish multi-centre study, which is supported by the Spanish Society of Nephrology (S.E.N.).31
We have had a diagnostic and interventional ultrasound unit at the Servicio de Nefrología (Nephrology Department) of the Ramón y Cajal Hospital since 1991.22-35 From this moment onwards, we have been able to examine our patients (those suffering from kidney diseases and transplant recipients) using conventional ultrasound, later implementing Doppler imaging. Our initial idea was to recover the renal biopsy technique, but, in our experience, incorporating these diagnostic procedures in the nephrology department’s daily routine has been extremely useful. It is an important tool for diagnosing and monitoring patients suffering from clinical kidney diseases, high blood pressure, or receiving kidney transplants.
Since 1995, we have been surgically implanting catheters for peritoneal dialysis. Since 2010, we have been evaluating the vascular access using ultrasound (pre- and post-surgery) and placing transitory central catheters using real-time ultrasound. Lastly, in our department, we also perform minor surgery, such as removing Schon tunnelled catheters (which was previously performed by vascular surgeons), repairing peritoneal catheters and draining abscesses.
Interest with regards diagnostic and interventional nephrology is growing in Spain, something which is reflected in the number of courses taking place.36,37
DISADVANTAGES AND OBSTACLES
Our first obstacle is that we must overcome the assumption that we are stepping into other specialist’s fields,which is not the case, as we are relieving other specialities of numerous examinations and interventions, which may be of the utmost importance to us, but are less of a priority for them. In either case, there should be consensus with regard to interventional nephrology throughout the hospital so that it benefits the patients.
Another disadvantage, in our opinion, is that more focus is given to interventional nephrology than other areas. In our hospital there is a nephrologist who organises the Unidad de Nefrología Diagnóstica e Intervencionista (diagnostic and interventional nephrology unit), which is integrated by other nephrologists from the department. Each one is not only responsible for a given nephrology area, but also performs interventions. Given that they are continuously in contact with their patients, techniques are performed more swiftly. We have standardised each and every one of the activities performed in our department to avoid outcome variability.
Lastly, excessive workload is one of the main reasons for diagnostic ultrasound and interventional techniques being included as part of our routine. This has therefore improved the situation for other specialities (e.g. cardiology) by increasing staff.
CONCLUSION
Diagnostic and interventional nephrologists provide complete, rapid treatment to resolve problems associated with kidney diseases. We are able to recover diagnostic and treatment techniques from other specialists. If nobody is able to imagine a cardiologist living without an ultrasound machine or a cath lab, then maybe it would not be so difficult to envisage a “new type of nephrologist”, who would be a master of ultrasound, perform renal ultrasounds and vascular mapping of the upper extremity to gain vascular access, perform ultrasound-guided biopsy and provide early diagnosis for vascular access complications. Nephrologists would also be responsible for starting dialysis programmes, as it would be them who place tunnelled catheters for haemodialysis and the peritoneal catheter or perform arteriovenous fistula surgery. Furthermore, they would be capable of evaluating chronic kidney patients’ cardiovascular risk, adapting treatments to these parameters throughout the disease’s development.
To achieve these goals, nephrologists must complete training in experienced centres and scientific societies must create training programmes and establish the minimum accreditation requirements. In this respect, we recognise the S.E.N.’s interest in promoting this type of programme. In Spain, the national commission for this speciality should assess whether these skills should be included in the nephrologists training programme. This new approach to nephrology may make this discipline more attractive to future resident junior doctors.
