Are textbook lungs really normal? A cadaveric study on the anatomical and clinical importance of variations in the major lung fissures, and the incomplete right horizontal fissure

Eureka: objective assessment of the empty pelvis syndrome to measure volumetric changes in pelvic dead space following pelvic exenteration

BACKGROUND

Large tissue defects following pelvic exenteration (PE) fill with fluid and small bowel, leading to the empty pelvis syndrome (EPS). EPS causes a constellation of complications including pelvic sepsis and reduced quality of life. EPS remains poorly defined and cannot be objectively measured. Pathophysiology of EPS is multifactorial, with increased pelvic dead space potentially important. This study aims to describe methodology to objectively measure volumetric changes relating to EPS.

METHODS

The true pelvis is defined by the pelvic inlet and outlet. Within the true pelvis there is physiological pelvic dead space (PDS) between the peritoneal reflection and the inlet. This dead space is increased following PE and is defined as the exenteration pelvic dead space (EPD). EPD may be reduced with pelvic filling and the volume of filling is defined as the pelvic filling volume (PFV). PDS, EPD, and PFV were measured intraoperatively using a bladder syringe, and Archimedes' water displacement principle.

RESULTS

A patient undergoing total infralevator PE had a PDS of 50 ml. A rectus flap rendered the pelvic outlet watertight. EPD was then measured as 540 ml. Therefore there was a 10.8-fold increase in true pelvis dead space. An omentoplasty was placed into the EPD, displacing 130 ml; therefore, PFV as a percentage of EPD was 24.1%.

CONCLUSIONS

This is the first reported quantitative assessment of pathophysiological volumetric changes of pelvic dead space; these measurements may correlate to severity of EPS. PDS, EPD, and PFV should be amendable to assessment based on perioperative cross-sectional imaging, allowing for potential prediction of EPS-related outcomes.

The Prediction of Fissure Integrity by Quantitative Computed Tomography Analysis

BACKGROUND

Incomplete interlobar fissure may increase the difficulty of thoracoscopic lobectomy. Herein, we compared the accuracy of visual versus quantitative analysis to predict fissure integrity in lung cancer patients undergoing thoracoscopic lobectomy and evaluated the effects of fissure integrity on surgical outcome.

METHODS

This was a single-center retrospective study including consecutive patients undergoing VATS (video-assisted thoracoscopic surgery) lobectomy for lung cancer. The target interlobar fissures were classified as complete or incomplete by visual and quantitative analysis. Using the intraoperative finding as the reference method, the diagnostic accuracy of the two methods to define fissure completeness (dependent variable) was calculated and statistically compared. Yet, we evaluated differences in postoperative outcomes between patients with complete and incomplete fissure integrity.

RESULTS

A total of 93 patients were included in the study; 33/93 (36%) presented complete fissure. Visual and quantitative analyses correctly identified complete fissure in 19/33 (57%) and 29/33 (88%) patients, respectively, and incomplete fissure in 56/60 (93%) and 58/60 (96%) patients, respectively. Quantitative analysis had better diagnostic accuracy than visual analysis (81 vs. 93%; p = 0.01). Patients with incomplete fissure compared with those with complete fissure had a higher conversion rate (6 vs. 13%; p = 0.43), higher persistent air leak rate (0/33 vs. 14/60; p = 0.03), and longer hospitalization (12.6 ± 3.8 vs. 7.1 ± 2.4 days; p = 0.01).

CONCLUSION

Quantitative analysis accurately predicted the fissures' integrity; it may be useful for selecting suitable cases for thoracoscopic lobectomy especially for surgeons with limited minimally invasive experience.

Multi-center experience in an optimized right upper lobectomy surgical procedure in China

BACKGROUND

This multi-center study was aimed at retrospectively evaluating the feasibility, safety, clinical outcomes, and surgical learning curve of an optimized procedure for right upper lobectomy (RUL), which is challenging because of the anatomical structures and features of this lobe.

METHODS

This study included 45 RUL cases of robot-assisted thoracoscopy (RATS) in a pilot cohort and 187 RUL cases of video-assisted thoracoscopy (VATS) in three cohorts. A total of 121 and 111 patients underwent traditional and optimized RUL, respectively. The optimized surgical procedure was performed to consecutively transect the superior arterial trunk and bronchus, and finally disconnect the pulmonary vein and posterior ascending artery with interlobar fissures. Clinical and radiological data were reviewed retrospectively.

RESULTS

Optimized RUL can be performed successfully by RATS or VATS. The optimized procedure yielded better clinical outcomes than the traditional procedure, including shorter operation times, less blood loss, fewer complications, shorter hospital times, lower costs, and a lower likelihood of postoperative intermedius bronchial kinking. Additionally, for calcified interlobar lymph nodes, the optimized VATS group was less likely to be converted to thoracotomy than the traditional group. The skills required to perform optimized VATS RUL can be gained by surgeons after 12 to 15 cases. The two RUL procedures in the pilot cohort showed similar disease-free survival.

CONCLUSIONS

The optimized RUL was safe, economical, and feasible, with a short learning curve and satisfactory disease-free survival.

The prevalence of the azygos lobe: A meta-analysis of 1,033,083 subjects

The azygos lobe (AL) is an accessory lobe of the right lung with prevalence between 0.4 and 1.2%. The aim of the present review is to provide a better estimate of the frequency of the AL and to examine its relationships with other variables such as population, diagnostic methods, and co-occurring illnesses. Studies published between 1899 and October 2020 were searched through three electronic databases; Google Scholar, PubMed, and JSTOR. Titles, abstracts, and full texts of the retrieved entries were screened to determine their appropriateness for inclusion. A total of 88 studies relating to 1,033,083 subjects met the inclusion criteria. A random-effects meta-analysis yielded an overall prevalence of 0.30% (95% CI: 0.0024-0.0035, I²  = 97.9%). Linear regression and subgroup analysis revealed a negative correlation (ρ = -0.540, p <0.001) between AL prevalence and sample size; studies with smaller sample sizes had higher prevalences. The AL prevalence in individuals with congenital pulmonary defects, 5.2% (95% CI: 0.0018-0.0086, I²  = 0%), was 17 times higher than the overall prevalence (z = 6.65, p <0.001), suggesting associations with other abnormalities and possibly a genetic predisposition. In addition to an evidence-based synthesis of AL prevalence, this study demonstrates publication bias and small-study effects in the anatomy literature. Awareness of the AL is crucial for radiologists when they interpret unusual radiological findings and for surgeons when they operate in the region.