Hydrodissection of the Retrohepatic Space: A Technique to Physically Separate a Liver Tumour from the Inferior Vena Cava and the Ostia of the Hepatic Veins

2024 International Expert Consensus on US-guided Thermal Ablation for T1N0M0 Papillary Thyroid Cancer

Thermal ablation has started to gain acceptance as a therapeutic approach for the management of papillary thyroid cancer (PTC), mainly in the T1 stage (tumor size ≤ 2 cm in greatest dimension and limited to the thyroid). Despite its increasing popularity, a lack of uniformity in the technical details persists, and existing guidelines do not fully align with recent research advancements. To standardize the use of US-guided thermal ablation for T1N0M0 PTC, a panel of experts jointly issued this expert consensus on thermal ablation for PTC. This consensus was developed by experts with specific competence and expertise in this field through rounds of the modified Delphi method. An evidence-based approach incorporating the practical experience of the panelists was adopted. The consensus was developed through extensive discussions, systematic literature review with meta-analysis, and expert evaluations. In this consensus, a total of 27 recommendations are made, addressing the indications and contraindications for thermal ablation for PTC, physician training, preoperative preparation, technical procedures, complications, efficacy assessment, and follow-up strategies. This expert consensus provides up-to-date, high-quality, standardized guidance to harmonize treatment practices, enhance patient outcomes, and potentially shape future research and policy developments in the management of T1N0M0 PTC using US-guided thermal ablation.

Hydrodissection to create conjunctival flaps in dogs with corneal ulcers

Background and Aim

Hydrodissection is a liquid injection technique that is rarely used in animal ophthalmic procedures. The use of this technique in the creation of conjunctival flaps for the treatment of corneal ulcers in dogs can improve the outcome, task, and comfort for patients. This study aimed to evaluate the use of hydrodissection in the creation of conjunctival flaps in dogs with corneal ulcers.

Materials and Methods

This study focused on a surgical procedure for creating conjunctival flaps in the eyes of 17 dogs with deep corneal ulcers. We divided the patients into two groups: Hydrodissection was performed in the first group (G1) and conventional divulsion without hydrodissection in the second group (G2). In G1, the conjunctival flap was created by subconjunctival injection of 1 mL of 0.9% sodium chloride, followed by flap construction. The flap was constructed through conventional divulsion using iris scissors in the G2. The operative time, degree of bleeding, and ease of conjunctival divulsion were evaluated during the procedure. Blepharospasm, hyperemia, edema, and scarring of the conjunctiva were evaluated during the post-operative period. Post-operative complications, notably suture dehiscence, were recorded in each group.

Results

Hydrodissection is an easy-to-perform maneuver that optimizes the construction of conjunctival flaps. There were no statistical differences in the parameters used to evaluate the trans- and post-operative period between the groups. The volume of sodium chloride administered in the conjunctiva ranged from 0.5 mL to 1 mL in G1. Dehiscence of the flap sutures was observed in four patients (two in G1 and two in G2), with no significant difference between the groups.

Conclusion

Hydrodissection facilitates the construction of conjunctival flaps in dogs with corneal ulcers, affording greater comfort to patients and proving to be an excellent option for ophthalmologists.

Application and evaluation of hydrodissection in microwave ablation of liver tumours in difficult locations

Objective

To investigate the safety and mid-term outcomes of hydrodissection-assisted microwave ablation (MWA) of hepatocellular carcinoma (HCC) in various difficult locations.

Methods

A total of 131 HCC patients who underwent ultrasound-guided MWA from March 2017 to March 2019 were included. Following ultrasound examination, patients with tumors at difficult locations were treated with hydrodissection-assisted MWA (hydrodissection group), while those with tumors at conventional locations received MWA (control group). Both groups were compared concerning baseline characteristics, ablation parameters, complete ablation rates, and complication rates. Kaplan-Meier curves analyzed local tumor progression and overall survival, with stratified analysis for different difficult locations (adjacent to gastrointestinal tract, diaphragm, and subcapsular tumors). Additionally, Cox regression analyses were conducted to assess the impact of different difficult locations on these outcomes.

Results

Complete ablation rates were similar between the hydrodissection and control groups (91.4% vs. 95.2%, P>0.05). Postoperative complications occurred in three patients, including liver abscess and biliary injury. No significant differences in major or minor complication rates were found between the groups (P>0.05). Local tumor progression was detected in 11 patients (8.4%) at the end of the follow-up period. Neither cumulative local tumor progression rate (P=0.757) nor overall survival rate (P=0.468) differed significantly between the groups. Stratified analysis showed no effect of tumor location difficulty on cumulative local tumor progression or overall survival. Tumor number and size served as independent predictors for overall survival, while minimal ablation margin ≤ 5mm independently predicted local tumor progression. In contrast, the tumor location was not statistically significant. Sensitivity analyses corroborated the robustness of the models.

Conclusion

Hydrodissection-assisted MWA for HCC in various difficult locations demonstrated safe and effective, with complete ablation and mid-term outcomes comparable to those for tumors in conventional locations.

Adjunctive hydrodissection of the bare area of liver during percutaneous thermal ablation of sub-cardiac hepatic tumours

OBJECTIVE

To report the technique of hydrodissection of the sub-diaphragmatic bare area of the liver, in order to protect the diaphragm/heart during percutaneous thermal ablation (PTA) of sub-cardiac hepatic tumours.

MATERIALS AND METHODS

Between January 2016 and December 2018, five patients (four female, one male; mean age 56.2 years) with five sub-cardiac liver tumours (two hepatocellular carcinoma, three metastases; mean size 39 mm) abutting the bare area (segments II/IVA) with expected ablation zones ≤ 5 mm from the myocardium were treated with PTA and adjunctive hydrodissection. Time to perform hydrodissection, distance between superior hepatic and diaphragmatic/pericardial surfaces before and after hydrodissection, ablation efficacy, complications, and local tumour progression (LTP) at last imaging follow-up were recorded.

RESULTS

Technical feasibility was 100%, with mean hydrodissection-volume of 126 ml (range 80-200 ml) and median hydrodissection-time of 9 min (range 8-45 min). Liver-diaphragmatic and liver-pericardial distance increased, respectively, from 2.4 mm (range 0-8 mm) to 10.8 mm (range 6-19 mm) and from 4 mm (range 1-10 mm) to 12.6 mm (range 8-20 mm) post-hydrodissection. All procedures were performed at full-power with complete tumour ablation and without complications (including peri-procedural haemodynamic/electrocardiographic disturbances, pericardial effusion and diaphragmatic hernia) or evidence of LTP at mean 12.2-month (range 1-26 month) follow-up.

CONCLUSION

Hydrodissection of the sub-diaphragmatic bare area of the liver is technically feasible and may potentially optimize safety PTA of sub-cardiac hepatic tumours.

Percutaneous Radiofrequency Ablation for Liver Tumors: Technical Tips

Percutaneous radiofrequency ablation (RFA) has been accepted as a minimally invasive therapeutic treatment for liver malignancies. Although RFA is usually applied for the treatment of small liver tumors (<3 cm), several technical developments have expanded the use of RFA. RFA is now used for the treatment of large liver tumors, and the number of complications associated with this treatment has decreased. These refinements may ultimately lead to better long-term prognosis. Here, we review recent refinements of liver RFA and provide technical tips.