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DEFLUX FOR REFLUX

JANAK D DESAI

Samved Hospital, Navrangpura, Ahmedabad.

Vesicoureteral reflux is a urinary tract anomaly that affects approximately 1% of children. It means that one out of every 100 children born will have some degree of U-V reflux. This congenital disorder with such a high incidence has a risk of long term renal damage. This condition is frequently associated with urinary tract infection and the reflux of this infected urine can lead to renal scarring. And in the long-term renal insufficiency and hypertension. The reflux has a severity ranging from grade I (mild) to grade V (severe). A voiding cystourethrogram is the usual method for diagnosing and grading severity.

Treatment of vesicoureteral reflux is performed to prevent reflux associated urinary tract infection, thus minimizing the risks of renal scarring and long-term consequences. This treatment can be attempted either by medical or surgical procedures. Medical or conservative management involves long-term antibiotic prophylaxis to prevent the occurrence of urinary tract infection while reflux persists. This conservative approach relies on spontaneous resolution of vesicoureteral reflux; there is an approximately 15% downgradation of reflux every year. This means that a child with grade III reflux has a 15% chance that the reflux may become grade II after one year and grade I after two years. Therefore if we manage to prevent infection in these children it is possible that the reflux may be corrected naturally. This spontaneous resolution of V-U reflux decreases with increasing reflux grade. Conservative treatment avoids the risk of surgery but has the inherent disadvantage of long term antibiotics and thereby developing antibiotic resistance. In contrast, open surgery offers a high rate of cure with a relatively small risk of complications. This treatment is reserved for more severe reflux and involves a major surgical procedure that requires a hospitalisation for several days. Endoscopic treatment of V-U reflux was suggested, in 1981, as an alternative treatment to open surgery and conservative treatment. It involves the injection of material into the bladder wall below the ureteral orifice to elongate and augment the intramural part of the ureter, and prevent reflux of urine into the ureter. Being a simple and convenient procedure it has gained popularity.

So far two materials have been tried (and given up) for submucosal injection therapy :

1. Polytetrafluroethylene (PTF)

2. Silicone

PTF : It is not biodegradable and can form granulomas at the local injection site or at distant organs.

Silicone : It is associated with autoimmune reactions and a possible risk of malignancy.

Now biodegradable materials are used for the injection therapy. Materials used are :

1. Bovine collagen

2. Dextranomer microspheres (Deflux)

3. Macroplastique

Bovine collagen can elicit immunological reactions and the long term efficacy has been questioned.

A good study has been done on Deflux (made by a Swedish company) by a group of Swedish researchers (Uppsala University). They have studied more than 250 patients for a period of more than 2 to 7 years. We have done 5 cases and followed them for a period of more than 1 year upto 2 years. The material is very easy to inject and does not require any special equipments other than a paediatric scope. The patients were subjected to routine/microscopic urine tests every three months; MCU after 6 months and one year; IVP after 6 months and sonography every 3 months. Our results were as follows :

Out of the 5 cases 4 children had bilateral reflux and one child had unilateral reflux. Out of the 9 units treated there was a very good response in 8 units. One child who had grade V reflux did not have any benefit. He was subjected to open surgery after one year. We intend to do follow-ups for at least 10 years.

From our small experience and review of world literature the following data has emerged :

1. Deflux may be tried as a first line of treatment for all reflux cases. The results are better with reflux upto grade III.

2. The material is very easy to implant. Usually one ml is sufficient for one side but in some situations upto two ml may be required.

3. If the treatment is not successful, open surgery may be offered and the tissues do not show any adverse reactions. Open surgery remains as easy as in virgin tissues.

4.Reimplanting Deflux can also be tried in some failure cases - a second reimplantation may lead to cure.

5. Children with grade III or greater reflux at the end of three months may be offered a second reimplantation or open surgery (if requested/demanded by the parents).

6. The material (Dextranomer/hyaluronic acid copolymer) is a biodegradable substance. The implant volume may decrease after sometime but there is ingrowth of collagen and therefore stabilisation of the implant; the total decrease in volume may be upto 23% - this maintains a long-term efficacy.

7. The microspheres are of large size and therefore migration to distant sites (e.g. in teflon) is not possible.

There are no anaphylactic reactions to this material.

Once the Indian experience increases we should be in a better position to discuss more things about this new and exciting material.



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