Chyluria is a urological manifestation of lymphatic system disease. Sclerotherapy means instillation of renal pelvis with various chemical compounds which act as sclerosants. This endoscopic sclerotherapy is minimally invasive and effective in majority of the patients. The search for an ideal agent continues. The various agents used as sclerosants are as follows: [123]
- silver nitrate (0.1-1%),
- an amount of 0.2% povidone iodine,
- an amount of 15-25% sodium iodide,
- an amount of 10-25% potassium bromide,
- an amount of 50% dextrose,
- an amount of 76% urograffin,
- hypertonic saline (3%),
- combination therapy.
INDICATIONS FOR SCLEROTHERAPY
Failure of conservative management-DEC therapy and dietary modifications.
METHOD OF INSTILLATION
Once diagnosis of chyluria is confirmed, cystoscopic visualization of the affected unit is done and ureteric catheter is placed on the same side. A fatty meal previous night facilitates the identification of the affected side. The procedure is usually performed under local anesthesia and sedation. After ureteric catheter placement the patient is taken to the radiological suite and the renal pelvis capacity is measured. The sclerosant is instilled in the same amount as the renal pelvis capacity, which is usually 7-10 ml. During instillation of the sclerosant the patient should be placed in head down position and the sclerosant should be injected slowly while taking care of the pain threshold for an individual. Over distension of the renal pelvis should not be done. The instillation should be done under strict aseptic conditions and patient should receive analgesics and antibiotics for at least 5 days.
Mechanism of action of the sclerosant
Injected sclerosant reaches lymphatics through the pyelolymphatic fistula where it induces an inflammatory reaction in the lymphatics. This leads to chemical lymphangitis and oedema of the lymphatic channels. Finally, healing occurs by fibrosis causing blockade of the offending lymphatics and communicating lymphatic fistula (Figure 1).
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Figure 1: Showing probable mechanism of action of RPIS
Silver nitrate
It is the most commonly used sclerosant and the concentration ranges from 0.1 to 1%. It is effective in 60-84% of cases as shown in (Table 1). Procuring and precisely weighing good quality silver nitrate, its water insolubility, susceptibility to light, and the need for autoclaving the solution are the main disadvantages in choosing it as a preferred agent, especially for small hospitals, and clinics. It is difficult to maintain an exact concentration of solution as some of the water evaporates during autoclaving. Moreover, the need for freshly prepared solution in each patient sometimes results in an 8-24 h delay in starting therapy. Most important precaution is not to wash the ureteric catheter or the renal pelvis with normal saline as it leads to precipitation of silver chloride salts, which can lead to obstruction and other complications.
Table 1: Showing results of various sclerotherapy agents
Preparation
About 2 g of silver nitrate powder is dissolved in 200 ml of water in a bottle, which is wrapped in black paper and kept in a dark room. It is autoclaved for sterilization. Only freshly prepared solution should be used in each patient.
Povidone iodine
Povidone iodine is a water-soluble, nonionic surfactant polymer (polyvinyl pyrrolidone), which releases iodine slowly. Shanmugam et al. studied the instillation of 0.2% povidone iodine in five patients.[1] All patients had resolution of chyluria at end of 6 months of follow-up. Goel et al. also showed slightly better response with the use of povidone iodine as compared to silver nitrate.[4] The response was seen in 88% of patients with a mean follow-up of 24 months as shown in [Figure 2].
Figure 2: Kaplan–Meier survival analysis of DFD after the first course of RPIS; red line, povidone iodine; green dashed line, silver nitrate
Preparation
Povidone iodine 0.2% was prepared by 1 : 50 dilution of povidone iodine solution 10% w/v in distilled water. Freshly reconstituted povidone iodine should be used everytime in a patient.
Combination therapy
It consists of mixture of two sclerosants in a hope to get a better and stronger fibrotic response. Nandy et al. used combination therapy for the renal pelvic instillation where they combined povidone iodine with 50% dextrose. They showed a response rate of 87% with a recurrence rate of 13% in their study of 46 patients which were followed up for 24 months.[5]
Dose schedule
Instillation schedule: various protocols for the sclerosant instillation in chyluria are:
- 8 h instillation for 3 days,
- 12 h instillation for 2 days,
- weekly for 6-8 weeks.
Silver nitrate
Silver nitrate has been used in different concentrations (0.1-1%) and in different protocols, ranging from a single instillation to as many as nine doses.[1267] At our institute, 8 h instillation for 3 days (nine doses) is considered better than a single instillation (unpublished data). Tan et al.[6] used a single instillation of 0.5% silver nitrate in 55 patients with 11 (20%) had an immediate failure and 11 (23%) recurred after initial response. Authors reported success of 77% at 6.78 years.
Povidone iodine
Shanmugam used single instillation of povidone iodine in five patients and there was no recurrence in 6 months follow up.[1] We had studied two-types of dosage schedule in chyluria patients (unpublished data). In the first protocol, 8 h instillation of the povidone iodine was done for 3 days (total of nine doses) while in the second protocol weekly instillation of the povidone iodine was done for 6 weeks. The total number of patients included in the study was 27 in first protocol and 25 in the second protocol. At median follow-up of 32 months in 8 h instillations group there was 85% response rate with mean disease free duration (DFD) of 27 months. While in weekly instillation group a response rate of 75% with DFD of 22 months were observed. Now, we are using only 8 h instillation protocols in our patients.
Retreatment of chlyuria with sclerotherapy
In event of the recurrence of chyluria after first course of sclerotherapy, a second course of sclerotherapy should be instituted. The time of recurrence of the chyluria has a prognostic significance. In our study the 85 patients were prospectively randomized to receive 1% silver nitrate (n = 44) or 0.2% povidone iodine (n = 41) as renal pelvic instillation sclerotherapy (RPIS). In all, nine doses were given at 8-h intervals, and patients were followed at 6 weeks and then at 3-month intervals. Patients with 'persistence' or 'recurrence' of chyluria were treated with second course of RPIS using same sclerosant. We observed that in either group (povidone iodine or silver nitrate group) the patients who recurred earlier had a poorer response with the second course of sclerotherapy also.[4]
After first course of sclerotherapy eight patients out of forty-four patients in the silver nitrate group recurred, with three patients having immediate failure while five patients had delayed failure. When in these three patients with immediate failure, second-course of sclerotherapy was instilled, only one patient out of three had success (33%) at mean follow up of 20 months. An immediate failure to the second sclerotherapy was noted in the remaining two patients [Figure 3A]. In remaining five patients with delayed recurrence following first sclerotherapy, the second sclerotherapy was successful in four patients (80%, DFD - 20.3 months) at mean follow up of 25.4 months, while in the fifth patient had a delayed recurrence after of 24 months [Figure 3A].
Figure 3: Showing outcome of second course of RPIS (A – silver nitrate group, B – povidone iodine group)
After first course of sclerotherapy five patients out of 41 patients in the povidone iodine group recurred, with one patient having immediate recurrence while four patients had delayed recurrence. The patient with immediate failure after first course of renal pelvis instillation of povidone iodine recurred after 12 months following second course of same sclerosant instillation. The four patients with delayed recurrence, success was observed in three patients (75%) at a mean follow up of 20.3 months after second course of sclerotherapy. The one patient with delayed recurrence had a failure after second course of sclerotherapy around 9 months (Figure 3B).
It was concluded from the study that the patients who recur after first dose of sclerotherapy should be instilled with second course of sclerotherapy with a high success rate. The patients with immediate failure should be warned against possible recurrence.
CONCLUSION
The sclerotherapy has been found to be safe, effective and minimally invasive for treatment of chyluria. Recurrence of chyluria after first course of renal pelvic instillation of sclerosant can be treated with second course of renal pelvic instillation with a high success rate. The time to recurrence of chyluria after first sclerotherapy has a prognostic significance as the patients who have shorter DFD also fare poorly with the second course of sclerotherapy. Povidone iodine is as effective as silver nitrate in terms of efficacy and achieving cure with an advantage of lesser side effect profile[12].
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