Intrarenal pressure detection during flexible ureteroscopy with fiber optic pressure sensor system in porcine model

To validate the feasibility of a fiber-optic pressure sensor-based pressure measurement device for monitoring intrarenal pressure and to analyze the effects of ureteral acess sheath (UAS) type, surgical location, perfusion flow rate, and measurement location on intrarenal pressure (IRP). The measurement deviations and response times to transient pressure changes were compared between a fiber-optic pressure sensing device and a urodynamic device IRP in an in vitro porcine kidney and in a water tank. Finally, pressure measurements were performed in anesthetized female pigs using fiber-optic pressure sensing device with different UAS, different perfusion flow rates, and different surgical positions at different renal calyces and ureteropelvic junctions (UPJ). According to our operation, the result is fiber optic pressure sensing devices are highly accurate and sensitive. Under the same conditions, IRP varied among different renal calyces and UPJ (P < 0.05). IRP was lowest at 50 ml/min and highest at 150 ml/min (P < 0.05). Surgical position had a significant effect on IRP (P < 0.05). 12/14 Fr UAS had a lower IRP than 11/13 Fr UAS. Therefore fiber optic pressure sensing devices are more advantageous for IRP measurements. In ureteroscopy, the type of ureteral sheath, the surgical position, the perfusion flow rate, and the location of the measurement all affect the intrarenal pressure value.

Processed electroencephalography: impact of patient age and surgical position on intraoperative processed electroencephalogram monitoring of burst-suppression

We previously reported that processed EEG underestimated the amount of burst suppression compared to off-line visual analysis. We performed a follow-up study to evaluate the reasons for the discordance. Forty-five patients were monitored intraoperatively with processed EEG. A computer algorithm was used to convert the SedLine® (machine)-generated burst suppression ratio into a raw duration of burst suppression. The reference standard was a precise off-line measurement by two neurologists. We measured other potential variables that may affect machine accuracy such as age, surgery position, and EEG artifacts. Overall, the median duration of bust suppression for all study subjects was 15.4 min (Inter-quartile Range [IQR] = 1.0-20.1) for the machine vs. 16.1 min (IQR = 0.3-19.7) for the neurologists' assessment; the 95% limits of agreement fall within - 4.86 to 5.04 s for individual 30-s epochs. EEG artifacts did not affect the concordance between the two methods. For patients in prone surgical position, the machine estimates had significantly lower overall sensitivity (0.86 vs. 0.97; p = 0.038) and significantly wider limits of agreement ([- 4.24, 3.82] seconds vs. [- 1.36, 1.13] seconds, p = 0.001) than patients in supine position. Machine readings for younger patients (age < 65 years) had higher sensitivity (0.96 vs 0.92; p = 0.021) and specificity (0.99 vs 0.88; p = 0.007) for older patients. The duration of burst suppression estimated by the machine generally had good agreement compared with neurologists' estimation using a more precise off-line measurement. Factors that affected the concordance included patient age and position during surgery, but not EEG artifacts.

The effects of different surgical positions (semi-sitting and lateral position) on the surgical outcomes of large vestibular schwannoma: study protocol for a randomized controlled trial

Background

There is an ongoing discussion about the advantages and disadvantages of different surgical positions (semi-sitting and lateral position) for vestibular schwannoma surgery. Each position has its advantages, disadvantages, challenges, and risk profiles. The objectives of this study are to compare the effects of different surgical positions (semi-sitting and lateral position) on the outcomes of large vestibular schwannoma, primarily including effectiveness and safety.

Methods

In this single-centre, open, randomized controlled trial, we will recruit a total of 116 participants according to the inclusion and exclusion criteria who will be randomized to an experimental group or control group. Patients will undergo operations in semi-sitting and lateral positions. The primary endpoint will be the percentage of gross total resection. The secondary endpoints will include the facial nerve function, hearing preservation, surgical position placement time, time of operation (skin-to-skin surgical time), hospital stay, total hospitalization fee, and complications. The follow-up period will be at least 12 months, during which time patients will be evaluated both clinically and radiologically.

Discussion

This issue is still debated after 30 years since the first large comparative study was published in 1989, so the study will be useful. Therefore, more high-quality studies are required to compare clinical outcomes, complications, and other factors associated with these two positions.

Trial registration

Chinese Clinical Trial Registry ChiCTR1900027550. Registered on 17 November 2019

Lateral position: a friendly surgical position for intramedullary nailing of tibial shaft fractures via infrapatellar approach

BACKGROUND

The conventional infrapatellar approach to intramedullary nailing of tibial fractures adopts the supine high-flexion knee position. However, this has disadvantages including difficulty in obtaining the proximal tibial anteroposterior view during intraoperative fluoroscopy, prolonged duration of fluoroscopy. Accordingly, the present study investigated the utility of the lateral position in the infrapatellar approach to intramedullary nailing of tibial shaft fractures.

METHODS

The present study was a retrospective analysis of 112 patients who sustained closed tibial shaft fractures and treated with intramedullary nailing via the infrapatellar approach. Patients were divided into two groups according to surgical position: lateral or supine. The demographic and clinical data were collected and analyzed.

RESULTS

There were 54 patients in the lateral and 58 in the supine position groups. The duration of surgery and fluoroscopy was shorter in the lateral group than the supine group (p < 0.05). Blood loss during surgery was lower in the lateral compared with supine position group (p < 0.05). The malunion rate was lower in the lateral position group as compared with the supine position group (p < 0.05); moreover, fewer surgical assistants were needed than in the supine group (p < 0.05). There were no significant differences in fracture healing time, other complications between the two groups (p > 0.05).

CONCLUSIONS

The lateral position was a more convenient choice for intramedullary nailing of tibial shaft fractures via infrapatellar approach.

Application of a modified surgical position in anterior approach for total cervical artificial disc replacement

BACKGROUND

Total cervical artificial disc replacement (TDR) has been considered a safe and effective alternative surgical treatment for cervical spondylosis and degenerative disc disease that have failed to improve with conservative methods. Positioning the surgical patient is a critical part of the procedure. Appropriate patient positioning is crucial not only for the safety of the patient but also for optimizing surgical exposure, ensuring adequate and safe anesthesia, and allowing the surgeon to operate comfortably during lengthy procedures. The surgical posture is the traditional position used in anterior cervical approach; in general, patients are in a supine position with a pad under their shoulders and a ring-shaped pillow under their head.

AIM

To investigate the clinical outcomes of the use of a modified surgical position versus the traditional surgical position in anterior approach for TDR.

METHODS

In the modified position group, the patients had a soft pillow under their neck, and their jaw and both shoulders were fixed with wide tape. The analyzed data included intraoperative blood loss, position setting time, total operation time, and perioperative blood pressure and heart rate.

RESULTS

Blood pressure and heart rate were not significantly different before and after body positioning in both groups (P > 0.05). Compared with the traditional position group, the modified position group showed a statistically significantly longer position setting time (P < 0.05). However, the total operation time and intraoperative blood loss were significantly reduced in the modified position group compared with the traditional position group (P < 0.05).

CONCLUSION

The clinical outcomes indicated that total operation time and intraoperative blood loss were relatively lower in the modified position group than in the traditional position group, thus reducing the risks of surgery while increasing the position setting time. The modified surgical position is a safe and effective method to be used in anterior approach for TDR surgery.

Application of a Self-Made Equipment for Patient Positioning during Percutaneous Nephroscopy in the Oblique-Supine Position

BACKGROUND

The oblique-supine position for percutaneous nephrolithotomy (PCNL) has advantages, but the position fixation methods are inadequate. This study aimed to analyze the PCNL outcomes using a patented self-made frame for oblique-supine position.

METHODS

This was a prospective study of patients scheduled to undergo PCNL at 2 hospitals in China between November 2009 and December 2016. The patients underwent PCNL in the oblique-supine position using the self-made position frame (n = 94). Operative time, stone clearance rate, intraoperative average systolic pressure, intraoperative average heart rate, intraoperative average airway pressure, intraoperative average intrapelvic pressure, and complications were observed.

RESULTS

The patients were 45.3 ± 19.7 years old and 71% were male. Stones were of the size 2.5 ± 1.1 cm. The operative time was 95.6 min and the stone clearance rate was 81.9%. Intraoperative systolic blood pressure was 15.13 ± 1.68 kPa. Intraoperative airway pressure was 15.5 ± 2.3 cm H2O. Postoperative fever was observed in 3.2% of the patients. None had organ injury. Postoperative stay was 4.8 ± 0.6 days. The nephrostomy tube was routinely removed on the 5th day after surgery and the patients were discharged on the following day.

CONCLUSION

The self-made surgical position frame met the position requirements for the oblique-supine PCNL operation. This surgical position frame deserves clinical application and promotion.