PAIRS technique for hydatid cyst

Hepatic Cystic Echinococcosis, is a parasitic infection primarily caused by the parasite Echinococcus granulosus. This page is dedicated to providing in-depth information on the latest medical, percutaneous, and surgical treatment options, including the use of drugs like Albendazole and Mebendazole, innovative procedures like PAIR (Puncture, Aspiration, Injection, Re-aspiration), and various surgical approaches for managing this condition and therefore understanding the complexities of Hepatic Cystic Echinococcosis treatment. We delve into the mechanisms, effectiveness, and nuances of each treatment method, alongside recommendations from the World Health Organization (WHO), to ensure a holistic and up-to-date perspective. Additionally, we explore vital pre-treatment procedures like Cholangiography and Endoscopic Retrograde Cholangiopancreatography (ERCP), crucial for effective treatment planning.

PAIRS outline:

Aspect	Details
PAIR Technique	Percutaneous drainage under guidance (ultrasonographic/CT), involving cyst puncture, scolicidal solution instillation, and reaspiration.
Drug Therapy	Oral albendazole or mebendazole, pre- and post-drainage. Doses and duration varied across studies.
Success Rates	High rates of clinical and parasitologic cure, with low recurrence rates.
Scolicidal Solutions	1. Variations across studies: - 20% Hypertonic saline (most commonly used) - Absolute alcohol (used for type III cyst with size larger than 5 cm) - Povidone iodine - Hydrogen peroxide - Iodine - Formalin - Silver nitrate - Albendazole 2. Type of agent didn’t significantly affect outcomes.
Complications	1. Major complications - Anaphylaxis - Biliary fistula 2. Minor (non-life-threatening/nosocomial). 3. Fewer complications compared to surgery.
Follow-up & Monitoring	Minimum 6 months, with regular ultrasonographic/CT scans and serologic tests.
Surgical Comparison	Compared to surgical methods (varied from conservative to radical), PAIR had higher efficacy, fewer complications, shorter hospital stays.

Ultrasonographic Classification for Hydatid cyst:

Gharbi Type	WHO Type	Cyst Morphology	Viability	Management
I	CE 1	Unilocular anechoic lesion with double line sign	Active	< 5 cm - Albendazole > 5 cm - Albendazole + PAIRS
III	CE 2	Multiseptated rosette like honeycomb cyst	Active	Albendazole + Surgery
II	CE 3A	Cyst with detached membranes (water-lily sign)	Transitional	< 5 cm - Albendazole > 5 cm - Albendazole + PAIRS
III	CE 3B	Cyst with daughter cysts in solid matrix	Transitional	Albendazole + Surgery
IV	CE 4	1. Cyst with heterogenous hypoechoic/hyperechoic contents resembling ball of wool 2. No daughter cysts	Inactive	Follow up
V	CE 5	Solid plus calcified wall	Inactive	Follow up

Management for Hydatid Cyst:

Category	Medical management	PAIRS	Surgical Options
Overview	1. Used in cases where surgery or percutaneous treatment isn't suitable, or as an adjunct. 2. Albendazole is the most commonly used drug. 3. Other Drugs - Mebendazole, Praziquantel	1. PAIR and secondary catheterization methods are used. 2. Less invasive, with high success rates in selected cases.	1. Once the most common treatment, now reserved for complicated (like ruptured cyst and cyst with biliary communication) or specific types of cysts (types CE2 and CE3b cysts). 2. Includes open and laparoscopic surgery options.
Mechanism of Action	1. Benzimidazoles - Interferes with glucose absorption in parasites, leading to degeneration. 2. Praziquantel - Increases parasite cell membrane permeability to calcium, causing contractions and paralysis.	1. Involves puncture, aspiration, injection (scolicidal solution for about 20–30 minutes), and re-aspiration of scolicidal solutions. Satisfies surgical goals but is less invasive. 2. Before performing any percutaneous drainage procedures, it's advised to conduct cholangiography or endoscopic retrograde cholangiopancreatography (ERCP). This step is crucial for injecting a contrast dye, which helps in identifying any links between the cysts and the biliary tree. Often, these biliary connections are not visible until the ERCP is performed, as the cyst's expansion before aspiration can obscure them. However, once the contrast material is injected, these connections become detectable.	1. Aimed at inactivating parasites, evacuating and obliterating the cyst cavity. Includes conservative and radical techniques. 2. Conservative techniques: - Simple tube drainage - Marsupialization - Capitonnage - Deroofing - Partial simple cystectomy, or - Open or closed total cystectomy with or without omentoplasty. 3. Radical Techniques: - Total pericystectomy - Partial hepatectomy - Lobectomy
Specifics	1. Albendazole dose: 10-15 mg/kg/day in two divided doses for 3-6 months. 2. Mebendazole dose: 40-50 mg/kg/day in three divided doses. 3. Praziquantel 50 mg/kg, either once weekly or bi-weekly.	1. PAIR is based on the destruction of the germinal membrane. 2. Secondary methods for types CE2 and CE3b cysts, and post-PAIR relapses. 3. Not recommended for cyst with non-absorbable contents or risk of spread of contents in abdominal cavity. 4. Cyst with diameter > 7.5 cm has high chances of communication with biliary channel	1. Radical surgery removes the cyst and pericystic membrane, sometimes with liver resection. 2. Conservative surgery removes only cyst contents.
Drug Interactions & Duration	1. Treatment lasts for 3-6 months. 2. Interactions with dexamethasone, praziquantel, cimetidine, and anti-epileptic drugs (phenytoin, carbamazepine, and phenobarbital).	Albendazole or mebendazole administered for 7 days pre- and 28 days post-drainage.	Initiate medical treatment 4-30 days prior to surgery and continue for at least 1 month for albendazole, and 3 months for mebendazole.
Efficacy	1. Less effective as monotherapy; often leads to partial cyst reduction and sterilization. 2. Monotherapy is effective in 28.5%-58% of cases.	High rates of clinical and parasitologic cure with lower rates of complications and recurrence compared to surgery.	Radical procedures are more effective with fewer complications and relapses compared to conservative techniques.
Complications	1. Headache, nausea, neutropenia, hair loss, hepatotoxicity. Monthly monitoring of leukocyte counts and liver function tests recommended. 2. Contraindicated in Liver Failure, Pregnancy and Bone marrow suppression.	1. Incidence of lethal anaphylaxis at 0.03%, allergic reactions at 1.7%. Lower risk of anaphylaxis. Fever and rash in 11%-13% of patients. 2. Biliary fistula and residual cavity relapse rates considerably lower with PAIR compared to conservative surgery. 3. Secondary echinococcosis caused by spillage 4. Chemical (sclerosing) cholangitis if cysts communicate with the biliary tree	Includes hemorrhage, bile exudation, fistula formation, cholangitis, infection, sepsis, and potential for anesthesia complications.

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