# Pitfall of Wide Wedge Resection: Risk of Overlooking Surgical Margin Shortage

## TL;DR

This study shows that deep wedge resection in lung surgery can create hidden cavities, potentially leading to inaccurate margin assessments.

## Contribution

The study identifies a new mechanism by which deep wedge resection may cause margin overestimation due to stapler-induced lung injury.

## Key findings

- CT imaging revealed empty spaces near staple lines in 30.3% of deep wedge resection specimens.
- Deeper resections and more stapler cartridges were significantly associated with cavity formation.
- Porcine models confirmed stapler compression can cause internal lung rupture without visible pleural damage.

## Abstract

The recent increase in sublobar resections has been driven by favourable long-term outcomes and advances in stapling devices. However, maintaining an adequate resection margin remains a critical oncological requirement. This study aimed to investigate whether deep wedge resection induces subpleural alveolar injury that could lead to margin overestimation by creating undetectable internal cavities.

We retrospectively analysed 33 consecutive patients who underwent wedge resection and CT imaging of resected lung specimens between December 2018 and February 2025. CT was performed on inflated specimens to better visualize internal lung architecture. We assessed the presence of an “empty space” adjacent to the staple line and correlated it with clinical factors, including depth of wedge resection (WR). Additionally, ex vivo porcine lung models were used to simulate deep WR, analyse compression effects, and identify histological damage caused by stapler compression.

CT imaging revealed empty spaces adjacent to the staple line in 10 of 33 specimens (30.3%), with a mean cavity length of 8.25 ± 3.2 mm. This artifact was significantly associated with deeper WR (≥26.3 mm) and increased stapler cartridge usage (median: 4 vs 3, P = .0298). In porcine experiments, compression to 2 mm thickness resulted in internal parenchymal rupture without pleural tearing, replicating the clinical findings.

This study identified a potential mechanism by which deep wedge resection may lead to overestimation of the pathological margin due to stapler-induced parenchymal rupture. Further large-scale studies integrating oncological outcomes are warranted to clarify how wedge resection and segmentectomy should be appropriately selected for deep peripheral lung lesions.

The long-term outcomes of sublobar resection for small peripheral non-small cell lung cancer (NSCLC) have been reported, leading to a growing acceptance of sublobar resection, including deep wedge resection.