Response to 2017-0288 by Kahriman et al.

We thank authors for their interest in our study (1). Although there are WHO-IWGE guidelines, there is a wide variation in the management of hydatid disease (2). It is obvious that the procedures are performed according to clinical experience. For this reason, it can be expected that there are differences between applications. We agree with some of their points; however, there are also points that we disagree. We would like to add the following points with thought to bring clarity.

First, the mentioned study which was compared with our study by the authors includes only WHO CE1 and CE3a hydatid cysts (3). In this study, the total complication rate is 12.5% (minor = 12%, major = 0.5%). They regarded urticaria-like rashes as minor complications; however, we regarded allergic reactions as major complications. The difference arises from the fact that no standard method was used to describe the complications. It might be better to use standard guidelines to define the complications. On the other hand, our study consisted of patients with WHO CE1, CE2, and CE3a cysts. CE2 cysts and large CE3a cysts were treated by the MoCaT procedure which requires placement of a large bore catheter to evacuate the cyst content (infected material, germinal membranes, and daughter cysts). Therefore, this procedure is time-consuming and is more likely to cause complications such as bleeding or infection. Moreover, higher complication rates have been reported in the literature (4).

Second, they use the 5.7-F catheter with the trocar technique. We agree that placement of a smaller diameter catheter which may be easier and less risky. It is clear that 5.7-F catheter will have the same function with an 8-F catheter in PAIDS procedure. However, we disagree the use of trocar technique. The trocar technique can be easily applied in superficial cysts. But, placement of catheter may be harder into deep-seated cysts and may be more traumatic if it fails in the first attempt. We use a Seldinger technique and an 8-F catheter for PAIDS procedure. We place the catheter after the injection of the scolicidal agent, which is considered to be the death of the scolices. During catheter placement, no tract dilatation was performed, and we do not think that this procedure could lead to leakage. No peritoneal seeding was observed in our series. They claim that the risk of seeding and anaphylaxis with the trocar technique is obviously lower than the Seldinger technique. We think that prospective, randomized trials are needed to say that the trocar technique is superior to the Seldinger technique in terms of the risk of seeding and anaphylaxis.

We agree with them that sometimes there may be difficulties in aspirate the fluid via an 18-gauge needle, and to be easy aspirate the fluid by the catheter. We can easily solve this difficulty by changing the position of the needle with the non-aggressive aspiration. In all cysts, intra-cystic fluid was completely drained. We think that catheterization is unnecessary in small cysts. Also, some authors suggest performing PAIR procedure in cysts larger than 6 cm. Catheterization is an undesirable process, especially in children and in patients with multiple cysts.

Lastly, they administer more alcohol (60–70% of the aspirated cyst volume), twice in the left and right decubitus positions. We agree that this protocol may maximize sclerosis. A number of studies using alcohol at volumes of 25–30% or 60–70% are available (3,5). There is no standardization in this respect. We use 95% absolute alcohol (25–35% estimated initial cyst volume) when the daily drainage amount drops below 10 mL, which is at 24 h at the earliest. During this time, there is already a slight reduction in the cavity. The main concern in terms of alcohol use is the risk of undesired sclerosis such as sclerosing cholangitis or peri-cyst tissue sclerosis. We speculate that not seeing a cysto-biliary fistula in the fluoroscopic images is not a guarantee that the alcohol given will not affect the small bile ducts. The actual frequency of sclerosing cholangitis due to these procedures is unknown (2). We think that low volume alcohol application is adequate and safe. Our results were satisfactory in terms of volume reduction.

Finally, along with advantages and disadvantages, it is acceptable to have some differences between the clinics in terms of the methods applied. We agree with them that the use of smaller catheters in the PAIDS procedure may be easier to place and less risky. However, because we get more satisfactory results, our current trend is to completely evacuate the cyst contents with the MoCaT procedure instead of the PAIDS procedure in large cysts.