Control of intraoperative bleeding with hydrostatic pressure during endoscopic surgery

Endoscopic biopsy of pineal tumors: two burr hole trans-foramen of Monro approach and endonasal trans-tuber cinereum approach

INTRODUCTION

The pineal region is a challenging area for neurosurgeons due to its innate anatomical features, such as its deep location, surrounding large draining veins, and adjacent critical neural structures.

DISCUSSION

There is a high proportion of malignant tumors in the pineal gland, especially in children, and they are frequently accompanied by obstructive hydrocephalus. These cases require that surgical procedures can make a pathological diagnosis to guide further treatment strategies and immediately resolve increased intracranial pressure. Simultaneous endoscopic third ventriculostomy and biopsy have been regarded as the first-line surgical intervention before establishing a definite treatment plan. However, it is not always successful because various factors affect the surgical procedures, such as the location and extent of the tumor, degree of ventriculomegaly, location and size of the massa intermedia, and size of the foramen of Monro.

CONCLUSION

Here, we briefly reviewed the points to be considered in endoscopic biopsy of pineal tumors and introduced an alternative surgical procedure, the endoscopic endonasal trans-tuber cinereum approach, to surmount the anatomical hurdles.

Endoscopic third ventriculostomy complications: avoidance and management in a stepwise manner

Background

Various complications of endoscopic third ventriculostomy (ETV) have been described. One has to recognize these complications and learn how to avoid them.

Methods

We performed a literature review regarding the reported complications of ETV procedures discussed in a correlated manner with the surgical steps. Furthermore, we reviewed the technical notes described by experienced neuroendoscopists, including surgical indications, choice of the endoscopic entry point and trajectory, anatomic orientation, proper bleeding control and tight closure, to prevent and deal with such complications.

Results and conclusion

A lesson learned that comprehensive knowledge of ventricular anatomy with proper orientation by studying the preoperative images is mandatory and one should be aware of all complication types and rates.

Importance of Hydrostatic Pressure and Irrigation for Hemostasis in Neuroendoscopic Surgery

Recently neurosurgical operations have been carried out with water irrigation such as endoscopic third ventriculostomy and tumor resections in ventricles. Water irrigation is one of several published methods that promote hemostasis; however, not enough experimental evidence exists on its efficacy. In this study, we investigate whether hydrostatic pressure and persistent irrigation promote hemostasis in neuroendoscopic surgery. We dissected tails of 12-16-week-old C57BL/6 male mice at 5 mm proximal from the tip and checked for bleeding times under dry and wet conditions at pressures of 0 cmH₂O, 10 cmH₂O, 15 H₂O, and 20 cmH₂O without persistent irrigation to bleeding point and 10 cmH₂O with persistent irrigation. We then examined the dissected edge with hematoxylin-eosin staining and measured the size of vessels. The average bleeding time of each group is as follows: dry: 203.4 sec, wet: 164.4 sec, 5 cmH₂O: 138.6 sec, 10 cmH₂O: 104.6 sec (P <0.001), 20 cmH₂O: 56 sec (P <0.001), and 10 cmH₂O with persistent irrigation: 72.8 sec (P <0.01 compared to 10 cmH₂O without persistent irrigation). The maximum caliber of mice's tail artery was 50-60 μm. Hydrostatic pressure and irrigation are important factors contributing to hemostasis.

Assessment of a self-assembling peptide gel, SPG-178, in providing a clear operative field for trabeculectomy surgery for glaucoma in an animal model

The presence of blood during ophthalmic surgery is problematic, as it can obstruct a surgeon’s view of the operative field. This is particularly true when performing trabeculectomy surgery to enhance ocular fluid outflow and reduce intraocular pressure as a treatment for glaucoma, one of the most common vision loss conditions worldwide. In this study, we investigated the performance of a transparent, self-assembling peptide gel (SPG-178) and its ability to maintain visibility during trabeculectomy surgery. Unlike the hyaluronic acid gel commonly used in ophthalmic surgery, SPG-178 did not permit the ingress of blood into the gel itself. Rather, it forced blood to flow peripherally to the gel. Moreover, if bleeding occurred under the SPG-178 gel, perfusion with saline was able to effectively flush the blood away along the interface between the SPG-178 and the ocular tissue (in this case scleral) to clear the surgical field of view. In experimental trabeculectomy surgeries with mitomycin C used as an adjuvant, there were no differences in the postoperative recovery of intraocular pressure or bleb morphology with or without the use of SPG-178. SPG-178, therefore, when used in a gel formulation, represents a new material for use in intraocular surgery to ensure a clear operative field with likely beneficial treatment outcomes.

Prevention of Complications in Endoscopic Third Ventriculostomy

A variety of complications in endoscopic third ventriculostomy have been reported, including neurovascular injury, hemodynamic alterations, endocrinologic abnormalities, electrolyte imbalances, cerebrospinal fluid leakage, fever and infection. Even though most complications are transient, the overall rate of permanent morbidity is 2.38% and the overall mortality rate is 0.28%. To avoid these serious complications, we should keep in mind potential complications and how to prevent them. Proper decisions with regard to surgical indication, choice of endoscopic entry and trajectory, careful endoscopic procedures with anatomic orientation, bleeding control and tight closure are emphasized for the prevention of complications.

Characterizing Pressure and Flow Rate for Aqueous Immersion Surgery

Hemorrhage control during surgery remains a major clinical challenge for surgeons. Bleeding can affect the safety and efficacy of any surgical procedure. There are well-established methods to address this side-effect of surgery, but all current technologies require the surgeon to direct attention to hemostasis rather than the continuance of the procedure. We have developed a novel surgical method, titled aqueous immersion surgery (AIS), that is able to sustain a bloodless surgical field by providing a controlled hydraulic pressure (immersion pressure) on the bleeding site. Together with the replenishment of an immersion fluid (immersion flow rate), AIS maintains optical clarity of the surgical field. This numerical study was undertaken to investigate the influence of the rate exchange of the immersion fluid on the concentration of blood, hence optical clarity therein. A 3-dimensional multicomponent simulation was performed to evaluate the mixing of blood from an idealized arterial bleeding vessel under pulsatile conditions. With an increase in immersion pressure, bleeding was reduced and increased perfusion was observed. Additionally, the magnitude and direction of the flow field affected the deflection of the bleeding trajectory and, in turn, affected the removal rate of blood from the surgical field. For an idealized case, an optimal immersion flow rate was found for immersion pressures of 100 and 110 mm Hg. From this study, fluid dynamic guidelines are postulated to support future development of AIS.

The Department of Neurosurgery at Seoul National University: past, present, and future

The Department of Neurosurgery at Seoul National University College of Medicine is one of the oldest neurosurgical departments in Korea, and it is a center of academic leadership in neurosurgery. In September 1957, the department was established by Bo Sung Sim, and it has produced many leaders of neurosurgery in Korea. Chairmen Bo Sung Sim, Kil Soo Choi, Dae Hee Han, and Byung-Kyu Cho each brought special skills and talents to the development of the department. The current and fifth chair, Hyun Jib Kim, assumed the chairmanship in July 2000. The department comprises 11 full-time faculty members, 5 fellows, and 14 residents. More than 1,700 neurosurgical procedures are performed annually in four operating theaters. A gamma knife was installed in 1997, and approximately 200 gamma knife procedures are performed each year. In addition to clinical activities, research and education for graduate and postgraduate students are also particular strengths of the department. This article traces the clinical, academic, and scientific development of the department, its present activities, and its future direction.