Effect of pneumoperitoneum and Trendelenburg position on internal carotid artery blood flow measured by ultrasound during robotic prostatectomy

Factors related to clearance of the small pelvic cavity during gynecologic laparoscopic surgery

AIM

To identify factors influencing the Trendelenburg angle required during laparoscopic gynecological surgery.

METHODS

Patients who underwent laparoscopic surgery at a single university hospital between May 1, 2019, and March 31, 2021 were enrolled. Data were extracted from the medical records, while magnetic resonance imaging scans and all laparoscopic surgery videos were retrospectively reviewed to assess the presence of the small intestine in the pelvic cavity as well as the adhesions at each site. Groups with and without the small intestine in the pelvic cavity, and those requiring a Trendelenburg angle above or below 13° were compared.

RESULTS

In total, 219 patients were examined. The Trendelenburg angle was significantly higher (p = 0.004), while a significant increase in ovarian adhesions was observed (p = 0.033; odds ratio [OR], 2.30; 95% confidence interval [CI], 1.05-5.01) in the group without the presence of the small intestine in the pelvic cavity. Furthermore, the group requiring a Trendelenburg angle of ≥13° had significantly thicker subcutaneous fat (p = 0.044) and more ileal adhesions (p = 0.040, OR, 1.82; 95% CI, 1.03-3.23) than the group with an angle of <13°.

CONCLUSION

Cases of ileal adhesions or thick subcutaneous fat are more likely to require a Trendelenburg angle of ≥13°. Therefore, Trendelenburg complications should be considered in this group. In addition, ovarian adhesions make it more difficult to exclude the small intestine from the small pelvic cavity, and may be associated with endometriosis.

Position- and posture-dependent vascular imaging-a scoping review

OBJECTIVES

Position- and posture-dependent deformation of the vascular system is a relatively unexplored field. The goal of this scoping review was to create an overview of existing vascular imaging modalities in different body positions and postures and address the subsequent changes in vascular anatomy.

METHODS

Scopus, Medline, and Cochrane were searched for literature published between January 1, 2000, and June 30, 2022, incorporating the following categories: image modality, anatomy, orientation, and outcomes.

RESULTS

Out of 2446 screened articles, we included 108. The majority of papers used ultrasound (US, n = 74) in different body positions and postures with diameter and cross-sectional area (CSA) as outcome measures. Magnetic resonance imaging (n = 22) and computed tomography (n = 8) were less frequently used but allowed for investigation of other geometrical measures such as vessel curvature and length. The venous system proved more sensitive to postural changes than the arterial system, which was seen as increasing diameters of veins below the level of the heart when going from supine to prone to standing positions, and vice versa.

CONCLUSIONS

The influence of body positions and postures on vasculature was predominantly explored with US for vessel diameter and CSA. Posture-induced deformation and additional geometrical features that may be of interest for the (endovascular) treatment of vascular pathologies have been limitedly reported, such as length and curvature of an atherosclerotic popliteal artery during bending of the knee after stent placement. The most important clinical implications of positional changes are found in diagnosis, surgical planning, and follow-up after stent placement.

CLINICAL RELEVANCE STATEMENT

This scoping review presents the current state and opportunities of position- and posture-dependent imaging of vascular structures using various imaging modalities that are relevant in the fields of clinical diagnosis, surgical planning, and follow-up after stent placement.

KEY POINTS

• The influence of body positions and postures on the vasculature was predominantly investigated with US for vessel diameter and cross-sectional area. • Research into geometrical deformation, such as vessel length and curvature adaptation, that may be of interest for the (endovascular) treatment of vascular pathologies is limited in different positions and postures. • The most important clinical implications of postural changes are found in diagnosis, surgical planning, and follow-up after stent placement.

Relationships between common carotid artery blood flow and anesthesia, pneumoperitoneum, and head-down tilt position: a linear mixed-effect analysis

This study investigated the effects of pneumoperitoneum and the head-down tilt position on common carotid artery (CCA) blood flow in surgical patients.

METHODS

This prospective observational study included 20 patients who underwent gynecological surgery. CCA blood flow was measured using Doppler ultrasound at four-time points: awake in the supine position [T1], 3 min after anesthesia induction in the supine position [T2], 3 min after pneumoperitoneum in the supine position [T3], and 3 min after pneumoperitoneum in the head-down tilt position [T4]. Hemodynamic and respiratory parameters were also recorded at each time point. Linear mixed-effect analyses were performed to compare CCA blood flow across the time points and assess its relationship with hemodynamic parameters.

RESULTS

Compared with T1, CCA blood flow decreased significantly at T2 (345.4 [288.0-392.9] vs. 293.1 [253.0-342.6], P = 0.048). CCA blood flow were also significantly lower at T3 and T4 compared with T1 (345.4 [288.0-392.9] vs. 283.6 [258.8-307.6] and 287.1 [242.1-321.4], P = 0.005 and 0.016, respectively). CCA blood flow at T3 and T4 did not significantly differ from that at T2. Changes in CCA blood flow were significantly associated with changes in cardiac index and stroke volume index (P = 0.011 and 0.024, respectively).

CONCLUSION

CCA blood flow was significantly decreased by anesthesia induction. Inducing pneumoperitoneum, with or without the head-down tilt position, did not further decrease CCA blood flow if the cardiac index remained unchanged. The cardiac index and stroke volume index were significantly associated with CCA blood flow.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov (NCT04233177, January 18, 2020).

Preoperative bullae and subsequent pneumothorax in 6605 patients who underwent robotic prostatectomy

PURPOSE

Robotic prostatectomy is the most common surgical approach for treating prostate cancer. Patients undergoing robotic prostatectomy may have bullae, which may rupture leading to pneumothorax. We evaluated the incidence of pneumothorax due to preoperative bullae rupture in robotic prostatectomy.

METHODS

A large retrospective study of patients who underwent robotic prostatectomy between 2009 and 2021 was conducted. Bullae were detected using chest computed tomography. Pneumothorax was detected using a chest X-ray. The primary outcome was the incidence of pneumothorax due to bullae rupture. Secondary outcomes were the prevalence of preoperative bullae and the evaluation of postoperative outcomes, including length of hospital stay, intensive care unit admission rate, and prolonged intensive care unit stay (> 2 days).

RESULTS

A total of 6605 patients were included. The prevalence of preoperative bullae was 3.0% (196/6,605). There was no incidence of pneumothorax due to bullae rupture. No significant difference in the incidences of pneumothorax between patients with and without bullae (0/196 vs. 2/6,409, P > 0.999) was observed. In addition, length of hospital stay, intensive care unit admission rate, and prolonged intensive care unit stay were not significantly different between the two groups. Kaplan-Meier analysis showed that there was no significant difference in lengths of hospital stay between the two groups (log-rank test, P > 0.999).

CONCLUSION

In our cohort, there was no incidence of pneumothorax following robotic prostatectomy in patients with preoperative bullae. This result could help in the management of patients with prostate cancer with bullae.