Perfusion pressure as a determinant of respiratory function outcomes in unilateral biportal lumbar endoscopic procedures

Abstract

Introduction: UBE is used to treat most lumbar spine diseases, and it must rely on continuous infusion of saline to maintain a clear field of vision during the operation to ensure the smooth progress of the operation. Among many complications, the incidence of dural tear is the highest. Whether UBE can damage the dura and the effect of intraoperative perfusion pressure changes on respiratory function under different conditions are not clear.

Methods: In the present experiment, Wistar rats were implanted with diaphragmatic electrodes and divided into two groups (dura mater with rupture group and dura mater without rupture group). In the experiment, the perfusion pressure was continuously increased, and the water pressure was 6KPa, 10KPa and 14Kpa for 2 min, respectively. The changes of respiratory movement were observed and analyzed. The preoperative and postoperative MRI scan results were compared. Pathological staining was used to observe the spinal cord injury.

Results: Finally, we found that high perfusion pressure impaired respiratory function in rats with dural rupture, mainly manifested as decreased respiratory rate, but had no significant effect on respiratory function in rats with intact dura mater. HE staining and toluidine blue staining showed more nishi in the cauda equina nerve of the rats in the dural rupture group. Immunofluorescence results showed that the degree of cauda equina nerve injury in the dural rupture group was more severe than that in the dural rupture group.

Discussion: This study reveals the effects of perfusion pressure and dural injury on respiratory function in UBE, and avoiding dural sac rupture is an effective means to prevent and treat complications of UBE, which will provide a new perspective on UBE.

Keywords: diaphragm electromyography; lumbar vertebra; perfusion water pressure; respiratory movement; unilateral biportal endoscopy.

FIGURE 1

Schematic diagram of electrode and electrode implantation. (A) Pictures of electrodes: the three pictures on the right side show, from top to bottom, the needle end of the electrode, the part of the electrode in direct contact with the diaphragm, and the part of the electrode tail end connected to the signal receiver, respectively. (B,C) Yellow arrows show the implantation position of the right electrode, black arrows show the implantation position of the left electrode, and both implantation positions are at the junction of the diaphragm and white fat. (D) Cervical UBE surgical model: red arrow is the position of diaphragm electrode from the back, green arrow side of the hose connected to the pressure catheter, blue arrow direction catheter for saline perfusion channel.

FIGURE 2

Comparison of respiratory data of rats under different perfusion pressures during the simulated surgical procedure. (A) Comparison of respiratory data of the same group of rats under different perfusion pressures. (n = 4) (B) Comparison of respiratory data of different groups of rats at the same perfusion pressure. (n = 4) All data are means ± SD, *P < 0.05.

FIGURE 3

Original EMG and post integration EMG results (A) Raw EMG images and integrated EMG images of rats in group A during the experiment. (B) The EMG images of rats in group B during the experimental process and the EMG images after integration were selected.

FIGURE 4

Magnetic resonance imaging results of postoperative rats and preoperative rats (T2): From left to right, the MRI results are shown for rats in group A, rats in group B, and rats that did not undergo surgery.

FIGURE 5

HE staining and toluidine blue staining of spinal cord slices from rats after surgery. (A) HE staining of spinal cord sections of rats in group A and group B. (Scale bar 100 μm). (Scale bar: 100 μm) (B) Toluidine blue staining of spinal cord sections from rats in group A and group B. (Scale bar, 100 μm).

FIGURE 6

MBP staining and NF200 staining results of rat spinal cord sections after surgery. (A) MBP staining of rat spinal cord sections in group A and group B. (Scale bar, 50 μm). (B) NF200 staining of spinal cord sections from rats in group A and group B. (Scale bar, 50 μm).