Interventional Nephrology

J. Balasubramaniam

Senior Consultant, Nephrology, Kauvery Hospital, Tirunelveli, India

Correspondence: [email protected]

Nephrologists and Interventions

Interventions have always been part of every nephrologist’s day-to-day practice. Nephrologists were routinely creating vascular accesses and were mini surgeons doing Arterio-Venous Shunts. They were even called for help by others in their interventions- to assist cardiologists with their pace maker insertions and anaesthesiologists with jugular catheterisations [1]. The relevance of interventional nephrology in a developing country was well appreciated as early as 1989, when nephrologists were creating AV Shunts and were converting them to AV Fistulas [2]. Till recently it was rather inappropriate to call Interventional Nephrology a new entity.

But not anymore…

Unfortunately, many of these interventions have become lost arts for many nephrologists now. Aneasthesiologists and Intensivists insert vascular catheters, sonologists do renal biopsies, vascular surgeons create fistulas and urologists place PD catheters. When cardiologists do their echoes, nephrologists wait for sonologists; when gastroenterologists do their endoscopies, cystoscopy is forbidden for nephrologists. Nowadays nephrologists call ophthalmologists to rule out diabetic retinopathy, pulmonologists to tap pleural effusions and diabetologists to control blood sugars. When nephrologists are willing to wait for the cardiologists to diagnose and treat renal artery stenosis, it is indeed high time we take serious note of Interventional Nephrology.

Why should Nephrologists be interventionists?

The driving force to take up interventions differs from centre to centre, depending on the geographical location, available infra-structure, number of nephrologists and their work load. With more nephrologists passing out and good number of them willing to go to smaller towns and centres, the need for interventional nephrology is being realized all the more now.

Being in charge of planning and designing renal replacement therapy for his patients, with his unique clinical perspective and better understanding of the needs of the situation, the nephrologist is ideally suited for performing vascular access related procedures himself. This approach will minimize delays, decrease hospitalizations and decrease the use of temporary catheters, thereby improving medical care, decreasing costs and increasing patient convenience [3].

But yet, nephrologists continue to call different specialists for different procedures. Sometimes multiple specialists are called for the same procedure, although none of them are specifically trained for these interventions. Arteriovenous Fistula (AVF) is being created by vascular surgeons, cardiac surgeons, urologists, plastic surgeons and general surgeons in different centres.

Promotion of Interventional Nephrology to improve renal care delivery in developing countries.

Facility for renal care in developing countries is sparse and is centred predominantly in large cities. The majority of the ailing population, living in faraway villages, has no access to treatment even for reversible renal problems, leave alone for end stage renal failures. A Renal Medical Centre calls for team work by nephrologist, urologist, radiologist, sonologist, and vascular surgeon besides dialysis nurse, dietician, social worker and more. In developing countries, besides economic problems, lack of trained personnel is a limiting factor for upcoming new centres. This dissuades young nephrologists from going to smaller towns and thereby causes gross maldistribution of renal care facility.

A study undertaken to see if promotion of Interventional Nephrology can enhance delivery of renal care in developing countries [11], showed that:

  • Nephrologist – population ratio is low in India and the nephrologists are concentrated in big cities.
  • Renal care delivery is better in districts with Interventional Nephrologist, in spite of fewer nephrologists.
  • Promoting Interventional Nephrology among nephrologists and trainees can enhance delivery of renal care delivery to the rising number of populations with renal disease in developing countries.

Scope for Interventions:

  • Ultrasonogram / Doppler studies
  • Vascular access
    • Femoral, Jugular, Subclavian
    • Permcaths in various locations
    • A V Fistulas
    • A V Grafts
    • Salvaging failing fistulas with angioplasties
  • CAPD catheter insertions
    • Percutaneous
    • Endoscopic
    • Surgical
  • Renal Biopsy
  • Renal Angiograms/Angioplasties and other cathlab procedures.
  • Draining lymphoceles

USG/Doppler

Though there is nothing interventional about USG, it is critical that Nephrologists start doing renal sonograms. Not doing ultrasonogram was the starting point for the nephrologist’s woes…losing ground to other specialities. Look at the cardiologists, who, by keeping echocardiogram close to their chest, seem to have full control over all their activities. They have made it sound unethical if radiologists attempt echocardiogram or cardiac catheterization. Who made all these rules? It was only by convention and tradition. Now, with ever so many non-surgical treatments being designed for structural cardiac diseases, the cardiac surgeons are fast losing territory. But one should confess that it is great to see the cardiologist perform percutaneous balloon mitral/pulmonary valvuloplasty, how he confidently punctures the inter atrial septum, albeit with his echo machine to check and recheck the anatomy, and place arterial and venous catheters in situ to get his moorings right.

Nephrologists, by doing USG/Doppler would be better equipped to diagnose the cause of renal failure, hematuria and graft dysfunction, pick up more renovascular hypertension and ischemic renal failure. Isn’t it true now that more renovascular problems are brought to light by Cardiologists than Nephrologists?

Role of USG in renal biopsy, jugular and other vascular access, assessment of AV Fistula and acute graft dysfunction has become critical and essential. As sonologists cannot always be kept backpacked to nephrologists during routine day to day work, only option for nephrologists is to learn to do USG themselves. Doing USG study by someone with a sound background pathophysiological and clinical knowledge would not only lead to better and early diagnosis of renal diseases but also to identifying novel new sonological findings [5,6].

Making USG equipment as an essential component of renal wards and inclusion of its study in the curriculum of DM and Dip NB courses can make USG learning effortless. Renal Fellows may be posted in radiology department for short periods to hasten their learnings.

Renal Biopsy

Performing renal biopsy has always been a Nephrologist’s job. But a new trend of radiologist dashing in with a portable USG machine to do renal biopsy has begun! This was fuelled by the realization that it is more convenient, effective and so more ethical to do renal biopsy under USG guidance than to do a blind biopsy. When Nephrologists start performing USG themselves, this trend is likely to decline. More and more biopsies are being done under USG guidance by nephrologists, resulting in more yield of adequate sample and less of complications [7]. Even if real-time guidance is not possible with biopsy needle attachment to the probe, marking the depth and location of the biopsy site by the operator (nephrologist) himself makes a lot of difference to the outcome.

Tunnelled Catheter Placement:

Although, venous puncture and catheterization have always been done by Nephrologists, putting in a tunnelled Permcath is often left to the interventional radiologist. Now the trend is changing with more and more nephrologists undertaking this procedure. Live workshops and demos have kindled the interest and instilled confidence into many a new nephrologist. The use of tunnelled catheters is a veritable alternative for AV Fistulas in centres where surgical expertise is lacking and in situations where hemodialysis is started as a stopgap filler before renal transplantation.

AV Fistula

AV Fistula, the Achille’s heel of dialysis, can never be a ‘thrilling surgery’ or a soul satisfying exercise for even the junior vascular surgeon. No wonder, the nephrologist’s request is greeted with scant interest and renal patients are frequently posted last in a crowded theatre list to be handled by the junior surgeons with variable skill levels. This can result in fatal delays, and unpredictable outcomes. AVF by Nephrologist has been shown to be equally successful with less time delay, more distal fistulas and at less cost.

Doing AV Fistula by nephrologists might look a formidable task. But it is very much possible, if only the training is included in the DM / Dip NB curriculum. It is all about patience, perseverance and hard work than raw surgical skill. Advantages accrued out of the nephrologist creating AVF are very many. A comparative study of AVFs created by surgeon and Nephrologist has brought out very interesting facts [4]:

  • Timely access creation (less waiting)
  • More AVFs than grafts; more AVFs than catheters; more distal fistulas;
  • Cost reduction
  • More patient confidence and rapport
  • First hand assessment of the vascular atherosclerosis

Percutaneous insertion of CAPD catheter:

Advent of minimally invasive procedures for abdominal surgery have revolutionised the care of patients. Innovative use of ‘peel away’ catheter has made percutaneous PD catheter placement using Seldinger technique possible. This procedure enables the nephrologists to insert the CAPD catheter with minimal surgical trauma to the abdomen and enable quick start of the exchanges. Promoting PD Catheter placement by nephrologists shall make it convenient for both the nephrologist and the patient, and will go a long way in enhancing PD penetration as a RRT option [8].

It is time nephrologists enter Cathlab! [9]

At first instance it might sound audacious to let the nephrologists perform in the cath lab. But when we see what can be achieved through this, it is clear that it is not only logical but necessary too. When nephrologists are good at accessing vessels, there should be no problem in doing angiograms. Modern day angiogram catheters are so well designed that they too readily ‘slip’ and ‘fall’ into the target arteries. With some training and experience nephrologists would be as good as anybody else. Prof. Rajpurkar and his team have given a great lead for Indian nephrologists in management of Renal Artery Stenosis (RAS) [12]. It is so gratifying to see a stenosed vessel dilated and stented. It is rather unfortunate for the patients and the nephrologists that only a small portion of the renal disease burden is due to reversible RAS. But it still appears that RAS is an underdiagnosed entity. Complete Total Occlusion (CTO) of renal arteries is not uncommon. There should have been a stage when these were potentially reversible.

Many a time’s nephrologists are put in a spot of bother by the fear of contrast induced nephropathy (CIN), when renovascular disease is suspected in a patient with renal dysfunction. MR Angiogram cannot be an alternative because of the fear of gadolinium toxicity. With good expertise in Doppler study and with first-hand knowledge of the patient’s history and problem, an interventional nephrologist who can do angiograms should be the best person to judiciously use angiogram and pick up more RAS which require intervention. One can complete diagnostic angiograms with as little as 5 to 10 ml of contrast and complete renal angioplasty with 30 ml of contrast [9]. Emergence of a non-nephrotoxic contrast agent is the need of the day and the hunt is on. CO2 is being tried.

The root cause for all the present controversies in the management of RAS lies on the fact that nephrologists are currently involved in neither diagnosis nor treatment of this challenging problem.

Once Nephrologists are creating fistulas, doing angiograms, salvaging failing fistulas with vascular interventions like balloon dilatations and stenting of stenosed fistulas and coil closure of side branches will be well within their purview. Managing stenosed jugular, subclavian, SVC stenosis, placing IVC Filters, angioembolization for angiomyolipomas and renal biopsy bleeding, preoperative angionecrosis of renal tumors, and renal / adrenal vein sampling are some of the other procedures which are being done by nephrologists.

Recent interest in catheter based renal denervation and its potential impact on hypertension in kidney disease is opening new vistas. Although not yet an accepted procedure now, if this innovation proves effective, nephrologists are bound to lose a great opportunity if they are not amidst thick of cathlab activities. Again, cardiologists will be the gainers. But then controversies will be galore as in the management of RAS.

Problems expected to be faced:

Trying to do interventions for the first time will be met with lot of resistance from various quarters. Those of them, related to facilities and certain practical issues, are easily surmountable. But others call for sustained and collective effort. They are:

Learning

  • Training and certifications
  • Legal issues
  • Management of complications

Wrath of surgeons and other specialists

All good things come with a price. Problems are bound to be solved once interventions are taken up by large number of nephrologists. Presently, significant time is being allotted for Interventional Nephrology in various society meetings and conferences. Soon methodologies for training and certification will follow suit. Good relationship with other specialists is very important to learn as well as to manage complications. More the Nephrologist gets into it, more shall he be able to tackle the complications.

Mantras for aspiring young Interventional Nephrologists:

Future directions:

Intervention by nephrologists described above is not a mere wish list. They are practicable and are being carried out in centres in India and abroad.

Live Interventional Nephrology Workshop should become a regular affair until we sharpen our skills in more areas. Besides demos and hands- on training, the appropriate authorities are to be convinced to modify the DM and Dip NB curriculum to include these interventional training modules.

Nephrologist, instead of shying away, should step forward and bring Interventional Nephrology into practice. To cite Beathard, affectionately called the father of Interventional Nephrology – “a caring nephrologist has to be knowledgeable in the area of dialysis access, coordinate and develop strategies with the other team members and be an effective advocate for optimal patient care’.

References

  1. Balasubramaniam J. ISN (India) Text book of Nephrology, Chapter on Interventional Nephrology, 2012.
  2. Murthy ML, Niyamathullah MM, Hariharan S, et al. Conversion of arteriovenous shunts to fistulae for maintenance haemodialysis: its applicability in a developing country. J Assoc Physicians India. 1989;37(3):220-1.
  3. Vachhrajan TJ, Balasubramaniam J, Abraham G. The current state of interventional nephrology in India. Semin Dial. 2011.
  4. Balasubramaniam J, Balashanker C. Arteriovenous fistula (avf) construction by nephrologist – a necessity in rural nephrology practice (abstract w598) of the World Congress of Nephrology. June 8-12, 2003. Berlin, Germany. Nephrol Dial Transplant. 2003;18(4):3-829
  5. Balasubramaniam J et al. Renal Doppler in evaluation of Acute Renal Failure (ARF) – A prospective study. World Congress of Nephrology. June 8-12, 2003. Berlin, Germany. Nephrol Dial Transplant 2003; 18(4):3-829,
  6. Balasubramaniam J. Doppler Indices for Diagnosis of Renal Artery Stenosis. ISN SC CON 09, Indian Society of Nephrology – Southern Chapter, XXIX Annual Conference 2009.
  7. Yesudas SS. Percutaneous real-time ultrasound-guided renal biopsy performed solely by nephrologists: A case series. Indian J Nephrol. 2010;20:137-41
  8. Sampathkumar K, Ramakrishnan M, Sah AK, et al. Tunneled central venous catheter – Experience from a single center. Indian J Nephrol. 2011;21:107-11.
  9. Balasubramaniam J. Renal Angiogram/Angioplasty – It’s Time Nephrologists Enter Cath Lab!.Seminars in Dialysis 2013;26(3):366-70.
  10. Balasubramaniam J. Unpublished Data. Kidney Care Centre, Galaxy Hospitals, Tirunelveli, India. 2011.
  11. Balasubramaniam J., Karthik B., Palaniappan N. Can promotion of ‘Interventional Nephrology’ improve renal care delivery in developing countries? WCN2013 Satellite Meet. 9th Conference on Kidney Disease in disadvantaged population, Hong Kong 4-5 June 2013.
  12. Umapati Hegde, Mohan Rajapurkar, Sishir Gang, et al. Fifteen Years’ Experience of Treating Atherosclerotic Renal Artery Stenosis by Interventional Nephrologists in India. Seminars in Dialysis. 2012;25(1).97-104.
Dr.-J.-Balasubramaniam

Dr. J. Balasubramaniam

Senior Consultant

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