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Dolan et al. Mini-invasive Surg 2021;5:3 I http://dx.doi.org/10.20517/2574-1225.2020.101 Page 5 of 8
[29]
this work was not specified to include only high-risk patients. Hou et al. performed a specified meta-
analysis directly comparing segmentectomy to sublobar resection for high-risk patients in 9 studies. They
noted heterogeneous definitions for what qualified as high-risk, but most studies had followed Fernando
[1]
[29]
et al.’s criteria from their 2011 work mentioned earlier in this review. For OS, Hou et al. included 7
studies, and on meta-analysis found that the hazard ratio for segmentectomy compared to wedge resection
for stage I NSCLC was 0.80 in favor of improved OS with segmentectomy compared to wedge resection
[95%CI: 0.68-0.93; P = 0.004]. On subgroup analysis, there was comparable OS for stage I tumors ≤ 2 cm;
however, the hazard ratio favored improved OS with segmentectomy compared to wedge resection, 0.39
[29]
[95%CI: 0.15-1.02; P = 0.06] . Cancer-specific survival also favored segmentectomy over wedge resection,
hazard ratio 0.42 [95%CI: 0.20-0.88; P = 0.02]. They were unable to fully assess disease-free survival as only
3 studies reported data that was usable for comparison.

Unfortunately, even with all this data, the best option for high-risk patients who can undergo limited
resection, but not full lobectomy, remains unclear. Three randomized control trials are ongoing comparing
lobectomy to sublobar resection for early stage NSCLC, ≤ 2 cm with N0 lymph node status [30-32] . All three
studies have reported their peri-operative safety results and found no substantial differences. Suzuki et al.
[30]
noted a higher airleak rate in their 552 segmentectomy patients compared to their 554 lobectomy patients,
[31]
6.5% vs. 3.8%, P = 0.04. However, Altorki et al.’s report did not note an increased airleak in their
sublobar resection group, 340 patients total, compared to their 357 lobectomy patients. This was despite
including wedge resections and segmentectomies in their sublobar resection group; 201 wedge resection
[32]
[31]
patients and 139 lobectomy patients . Stamatis et al. noted equal rates of prolonged air leak in their 53
segmentectomy patients compared to their 54 lobectomy patients. Until the long-term outcomes of these
randomized control trials are evaluated, the choice of therapy should be determined by a multidisciplinary
team. Surgical resection, when feasible and preferably segmentectomy, remains the recommended
[3]
treatment if lobectomy is not possible .

SUBLOBAR RESECTION TECHNICAL POINTS: WEDGE RESECTION VS SEGMENTECTOMY
Patient selection remains of paramount importance for surgical procedure choice. Wedge resection and
segmentectomy are most appropriate for smaller, peripherally located lesions away from the hilum of the
lung. Segmentectomy should be favored when possible given its respect for anatomic planes, but comes
with a caveat. The target lesion mustlie within the boundaries of one segment or group of segments. One
of the authors has written extensively regarding this process and reported that patients with lesions under
2 cm that are resected with segmentectomy have no difference in outcomes compared to the patients treated
with lobectomy [33-35] . Segmentectomies are more technically challenging as the surgeon must create a fissure
between segments and then dissect out and ligate the segmental vessels and bronchus. Wedge resection is
performed without respect to anatomic planes or specific vessels, but can be useful when the target lesion is
very small (1 cm or less), subpleural, or crosses segmental borders. Care should be taken to ensure that the
margins from the edge of the tumor to the final staple line are appropriately wide to minimize recurrence
and that adequate lymph nodes are removed to ensure accurate staging [36-38] .

FUTURE DIRECTIONS
Radiomics is a rapidly growing field in which radiographic images are used to determine features such
as lesion shape, volume, texture, attenuation, and other factors that are not readily apparent or are too
[39]
difficult for an individual radiologist to assess visually or qualitatively . Radiomics is being studied to
predict histologic subtypes, specific mutations, and benefit of adjuvant chemotherapy after resection [40-42] .
Radiomics has already been used to predict OS in NSCLC; specifically, the recurrence of NSCLC after
SBRT [43-45] . Radiomics may even be able to predict survival based on resection type and offer high-risk
patients more tailored care.