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Page 2 of 22 Gharagozloo et al. Mini-invasive Surg 2020;4:68 I http://dx.doi.org/10.20517/2574-1225.2020.60
[2]
[1]
bronchopulmonary segments . In 1939, Churchill and Belsey reported the first anatomic segmentectomy,
[3]
a lingulectomy. Edward Boyden described the vascular and bronchial anatomy for pulmonary segments .
In the latter half of the twentieth century, the advent of antibiotic therapy led to a decrease in
segmentectomies performed for infectious lung processes and an increase in their use for primary
malignancies of the lung. In the 1960’s and 1970’s, Rasmussen and Clagett published reports of
[4]
segmentectomy for lung cancer with low mortality . With the introduction of stapling devices in the
late 1960’s, wedge resections, which were technically much easier, became widely used. Thereafter and
unfortunately, wedge resection, a nonanatomic pulmonary resection, and individual ligation anatomic
segmentectomy became grouped as “sublobar resections”. Subsequent studies showed that anatomic
[5]
segmentectomy was associated with significantly better cancer-related survival than wedge resection .
However, as anatomic segmentectomy is a technically more demanding procedure than lobectomy,
lobectomy became the procedure of choice for early stage lung cancer.

Recently, anatomic pulmonary segmentectomy has been shown to be a viable oncologic procedure for
early lung cancer, including patients who are elderly or have limited pulmonary reserve [6-14] . As a result of
high definition three-dimensional visualization and increased maneuverability of the surgical instruments
in a small space, the surgical robot has the distinct advantage of replicating the technique of anatomic
[15]
segmentectomy by thoracotomy using a minimally invasive platform . Although there has been skepticism
about the cost and the lack of evidence of the survival advantage of using robotic lobectomy, the robotic
platform seems to be especially suited to a minimally invasive approach to anatomic segmentectomy [15,16] .
Greater experience with the robotic platform has resulted in a reproducible anatomic segmentectomy
technique.

This is a companion paper to The Technique of Robotic Anatomic Segmentectomy I: Right Sided Segments.
This paper outlines the technique of anatomic pulmonary segmentectomy for the left lung: Left Upper Lobe
(LUL) Anterior Segment (S3), LUL Apicoposterior Segment (S1 + S2), LUL Lingulectomy (S4, S5), Left
Lower Lobe (LLL) Superior Segmentectomy (S6), and LLL Basal Segmentectomy (S7-S10).

ANATOMIC SEGMENTECTOMY IN THE LEFT LUNG
The bronchopulmonary segments of the left lower lobe are similar to the right lower lobe. Although there
are only two lobes in the left lung, there is some symmetry among the bronchopulmonary segments
bilaterally. However, some segments of the left lung merge, resulting in fewer bronchopulmonary segments
on the left than there are on the right lung [Figure 1].

The apicoposterior segment (S1 + S2) of the left upper lobe represents the fusion of the apical and posterior
segments. Although the Lingula is divided into two bronchopulmonary segments, the superior (S4) and
inferior (S5) Lingular segments, from a practical standpoint, S4 + S5 segmentectomy or lingulectomy is
typically performed. In the left lower lobe, there are four segments unlike the right lower lobe which has
five segments. The anteromedial basal segment (S7 + S8) represents the fusion of the anterior basal and
medial basal segments. The other segments (superior S6, posterior basal S10, and lateral basal S9) maintain
the same relative positions as observed in the right lung.

From a surgical standpoint, sublobar resection is usually performed for LUL anterior segment (S3), LUL
apicoposterior segment (S1 + S2), LUL lingulectomy (S4, S5), LLL superior segmentectomy (S6), and LLL
basal segmentectomy (S7-S10). It is possible to perform individual anatomic segmentectomy of the basal
segments S7 + S8, S9, or S10. We have no experience with robotic segmentectomy of these individual basal
segments and therefore have not included them in this report.