Tag: Surgical technique

Posted on

Laparoscopic versus open insertion of the peritoneal catheter in ventriculoperitoneal shunt placement: review of 810 consecutive cases

J Neurosurg 115:151–158, 2011. DOI: 10.3171/2011.1.JNS101492

Traditional ventriculoperitoneal (VP) shunt surgery involves insertion of the distal catheter by minilaparotomy. However, minilaparotomy may be a significant source of morbidity during shunt surgery. Laparoscopic insertion of the distal catheter is an alternative technique that may simplify and improve the safety of shunt surgery.

Methods. The authors performed a retrospective review of hospital records of all patients undergoing new VP shunt insertion at a tertiary care center between 2004 and 2009. Patient characteristics and outcomes were compared between patients undergoing open or laparoscopic insertion of the distal catheter. Independent variables in the analysis included age, sex, race, body mass index, surgical technique, previous VP shunt placement, previous abdominal procedures, American Society of Anesthesiology (ASA) score, and indication for shunt placement. Dependent variables included the occurrence of shunt failure, cause of shunt failure, complications, length of stay (LOS), LOS after shunt placement, estimated blood loss, and operative time.

Results. The authors identified 810 patients who met the inclusion criteria; open or laparoscopic distal catheter insertion was performed in 335 and 475 patients, respectively. There were no significant differences between the groups regarding age, race, ASA score, or indication for shunt placement. The most common indication was hydrocephalus due to subarachnoid hemorrhage, followed by tumor-associated hydrocephalus, normal pressure hydrocephalus (NPH), and hydrocephalus due to trauma. The incidence of shunt failure was not statistically different between cohorts, occurring in 20.0% of laparoscopic and 20.9% of open catheter placement cases (p = 0.791). With analysis of causes of shunt failure, shunt obstruction occurred significantly more often in the open surgery cohort (p = 0.012). In patients with a known cause shunt obstruction, distal obstruction occurred in 35.7% of the open cohort obstructions and 4.8% of the laparoscopic cohort obstructions (p = 0.014). The relative risk of distal obstruction in open cases compared with laparoscopic cases was 7.50. Infections occurred in 8.2% of laparoscopic cases compared with 6.6% of open cases (p = 0.419). Within the NPH subgroup, the laparoscopically treated patients had significantly more overdrainage (p = 0.040), whereas those in the open cohort experienced significantly more shunt obstructions (p = 0.034). Laparoscopically treated patients had shorter operative times (p < 0.0005), inpatient LOS (p < 0.001), and inpatient LOS after VP shunt placement (p = 0.01) as well as less blood loss (p = 0.058).

Conclusions. To our knowledge this is the largest reported comparison of distal VP shunt catheter insertion techniques. Compared with minilaparotomy, the laparoscopic approach was associated with decreased time in the operating room and a decreased LOS. Moreover, laparoscopy was associated with fewer distal shunt obstructions. Laparoscopic shunt surgery is a viable alternative to traditional shunt surgery.

Posted on

Venous sacrifice in neurosurgery: new insights from venous indocyanine green videoangiography

J Neurosurg 115:18–23, 2011. DOI: 10.3171/2011.3.JNS10620

The purpose of this paper is to evaluate whether venous indocyanine green (ICG) videoangiography has any potential for predicting the presence of a safe collateral circulation for veins that are at risk for intentional or unintentional damage during surgery.

Methods. The authors performed venous ICG videoangiography during 153 consecutive neurosurgical procedures. On those occasions in which a venous sacrifice occurred during surgery, whether that sacrifice was preplanned (intended) or unintended, venous ICG videoangiography was repeated so as to allow us to study the effect of venous sacrifice. A specific test to predict the presence of venous collateral circulation was also applied in 8 of these cases.

Results. Venous ICG videoangiography allowed for an intraoperative real-time flow assessment of the exposed veins with excellent image quality and resolution in all cases. The veins observed in this study were found to be extremely different with respect to flow dynamics and could be divided in 3 groups: 1) arterialized veins; 2) fast-draining veins with uniform filling and clear flow direction; and 3) slow-draining veins with nonuniform filling. Temporary clipping was found to be a simple and reversible way to test for the presence of potential anastomotic circulation.

Conclusions. Venous ICG videoangiography is able to reveal substantial variability in the venous flow dynamics. “Slow veins,” when they are tributaries of bridging veins, might hide a potential for anastomotic circulation that deserve further investigation.

Posted on

Stitched sling retraction technique for microvascular decompression: procedures and techniques based on an anatomical viewpoint

Neurosurg Rev (2011) 34:373–380. DOI 10.1007/s10143-011-0310-0

The success of microvascular decompression stitched sling retraction techniques for treating trigeminal neuralgia (TN), hemifacial spasm (HFS), and glossopharyngeal neuralgia (GPN), focusing on the stitching point for slinging the offending artery in the appropriate direction.

Between January 2007 and March 2009, 28 patients with TN, 5 patients with HFS, and 3 patients with GPN underwent MVD with a sling retraction technique. In cases of TN, MVD was performed using the infratentorial lateral supracerebellar approach, and the offending superior cerebellar artery was superomedially transposed with a sling stitched to the tentorium cerebelli. In cases of HFS, MVD was performed using the lateral suboccipital infrafloccular approach, and the offending vertebral artery was superolaterally transposed with a sling stitched to the petrous dura. In cases of GPN, MVD was performed using the transcondylar fossa approach, in which the posterior inferior cerebellar artery was inferolaterally mobilized with a sling secured to the jugular tubercle. No patient suffered recurrence in the follow-up period.

For the sling retraction technique to be performed successfully, it is important for a stitch to be placed at a suitable site to sling the offending vessel in the intended direction. An appropriate surgical approach must be used to obtain a sufficient operative field for performing the stitching procedures safely.

Posted on

Trigeminal schwannomas: experience with 57 cases and a review of the literature

Neurosurg Rev (2011) 34:159–171. DOI 10.1007/s10143-010-0289-y

Trigeminal schwannoma is a mostly benign tumor that can be cured by complete resection. Over the last few decades, several pioneers have developed surgical approaches enabling the total removal of such tumors.

We analyzed 57 patients who underwent radical surgery, including 45 patients who underwent skull base surgery as their initial treatment, for removal of trigeminal schwannomas. Here, we report the surgical management of these cases. Since 1990, all such patients have been treated using three main types of middle fossa skull base approaches, which minimize the exposure of the brain: the anterior transpetrosal approach, subtemporal interdural approach (Dolenc), or a combination of these approaches.

Before 1990, total tumor removal was achieved in only three of eight patients (38%). After 1990, the tumors were totally removed in 43 patients (90%) and were nearly completely removed in an additional three patients (6%). Among the patients who underwent skull base surgery as their initial treatment, a complete resection was achieved in 93% (42/45 patients) of the cases. However, total surgical removal after surgery and Gamma knife surgery was very difficult because of dense adhesions to the brain stem and cranial nerves. No surgery-related mortalities occurred in this series, and the individual KPS scores were more than 90% among the patients who underwent skull base surgery. No recurrences requiring additional surgery have occurred after an average follow-up period of 4.9 years.

Most of the trigeminal schwannomas could be removed totally and safely during a single operation after the introduction of skull base surgery. Therefore, radiosurgery should not be applied as the treatment of first choice for younger patients. A correct anatomical knowledge is critical for minimizing brain exposure and avoiding surgical complications.

Posted on

Skull base tumor model. Laboratory investigation

J Neurosurg 113:1106–1111, 2010. DOI: 10.3171/2010.3.JNS09513

Resident duty-hours restrictions have now been instituted in many countries worldwide. Shortened training times and increased public scrutiny of surgical competency have led to a move away from the traditional apprenticeship model of training. The development of educational models for brain anatomy is a fascinating innovation allowing neurosurgeons to train without the need to practice on real patients and it may be a solution to achieve competency within a shortened training period. The authors describe the use of Stratathane resin ST-504 polymer (SRSP), which is inserted at different intracranial locations to closely mimic meningiomas and other pathological entities of the skull base, in a cadaveric model, for use in neurosurgical training.

Methods. Silicone-injected and pressurized cadaveric heads were used for studying the SRSP model. The SRSP presents unique intrinsic metamorphic characteristics: liquid at first, it expands and foams when injected into the desired area of the brain, forming a solid tumorlike structure. The authors injected SRSP via different passages that did not influence routes used for the surgical approach for resection of the simulated lesion. For example, SRSP injection routes included endonasal transsphenoidal or transoral approaches if lesions were to be removed through standard skull base approach, or, alternatively, SRSP was injected via a cranial approach if the removal was planned to be via the transsphenoidal or transoral route. The model was set in place in 3 countries (US, Italy, and The Netherlands), and a pool of 13 physicians from 4 different institutions (all surgeons and surgeons in training) participated in evaluating it and provided feedback.

Results. All 13 evaluating physicians had overall positive impressions of the model. The overall score on 9 components evaluated—including comparison between the tumor model and real tumor cases, perioperative requirements, general impression, and applicability—was 88% (100% being the best possible achievable score where the evaluator strongly agreed with the proposed factor). Individual components had scores at or above 80% (except for 1). The only score that was below 80% was related to radiographic visibility of the model for adequate surgical planning (score of 74%). The highest score was given to usefulness in neurosurgical training (98%).

Conclusions. The skull base tumor model is an effective tool to provide more practice in preoperative planning and technical skills.

Posted on

Trigeminal schwannomas: experience with 57 cases and a review of the literature

Neurosurg Rev. DOI 10.1007/s10143-010-0289-y

Trigeminal schwannoma is a mostly benign tumor that can be cured by complete resection. Over the last few decades, several pioneers have developed surgical approaches enabling the total removal of such tumors.

We analyzed 57 patients who underwent radical surgery, including 45 patients who underwent skull base surgery as their initial treatment, for removal of trigeminal schwannomas. Here, we report the surgical management of these cases. Since 1990, all such patients have been treated using three main types of middle fossa skull base approaches, which minimize the exposure of the brain: the anterior transpetrosal approach, subtemporal interdural approach (Dolenc), or a combination of these approaches.

Before 1990, total tumor removal was achieved in only three of eight patients (38%). After 1990, the tumors were totally removed in 43 patients (90%) and were nearly completely removed in an additional three patients (6%). Among the patients who underwent skull base surgery as their initial treatment, a complete resection was achieved in 93% (42/45 patients) of the cases. However, total surgical removal after surgery and Gamma knife surgery was very difficult because of dense adhesions to the brain stem and cranial nerves. No surgery-related mortalities occurred in this series, and the individual KPS scores were more than 90% among the patients who underwent skull base surgery. No recurrences requiring additional surgery have occurred after an average follow-up period of 4.9 years.

Most of the trigeminal schwannomas could be removed totally and safely during a single operation after the introduction of skull base surgery. Therefore, radiosurgery should not be applied as the treatment of first choice for younger patients. A correct anatomical knowledge is critical for minimizing brain exposure and avoiding surgical complications.

Posted on

Best surgical practices: a stepwise approach to the University of Pennsylvania deep brain stimulation protocol

Neurosurg Focus 29 (2):E3, 2010. (DOI: 10.3171/2010.4.FOCUS10103)

Deep brain stimulation (DBS) is the treatment of choice for otherwise healthy patients with advanced Parkinson disease who are suffering from disabling dyskinesias and motor fluctuations related to dopaminergic therapy. As DBS is an elective procedure, it is essential to minimize the risk of morbidity. Further, precision in targeting deep brain structures is critical to optimize efficacy in controlling motor features. The authors have already established an operational checklist in an effort to minimize errors made during DBS surgery. Here, they set out to standardize a strict, step-by-step approach to the DBS surgery used at their institution, including preoperative evaluation, the day of surgery, and the postoperative course. They provide careful instruction on Leksell frame assembly and placement as well as the determination of indirect coordinates derived from MR images used to target deep brain structures. Detailed descriptions of the operative procedure are provided, outlining placement of the stereotactic arc as well as determination of the appropriate bur hole location, lead placement using electrophysiology, and placement of the internal pulse generator. The authors also include their approach to preventing postoperative morbidity. They believe that a strategic, step-by-step approach to DBS surgery combined with a standardized checklist will help to minimize operating room mistakes that can compromise targeting and increase the risk of complication.

Posted on

Posterior Communicating Artery Aneurysms: Technical Pitfalls

Neurosurg Q 2010;20:74–81

The posterior communicating artery aneurysms correspond on 25% of all ruptured aneurysms. The clinical course is typically a subarachnoid hemorrhage and third nerve palsy. We intend to introduce a new classification for PComA aneurysms to help neurosurgeons in day-to-day practice present. We review our experience in PComA aneurysms and discuss the main factors involving morbidity, mortality, signs and symptoms, and prognosis of these aneurysms.

Material and Methods: We reviewed historical records, images, surgical videos, and CDs of 46 surgically clipped aneurysms in 39 patients from June 2000 to July 2009, in 2 Institutions: Hospital Sa˜o Camilo and Santa Paula, Sa˜o Paulo, Brazil. They were classified in 2 groups, the A group composed by patients who presented subarachnoid hemorrhage in acute phase and the B group composed by incidental aneurysms carriers. All patients were classified according to Hunt-Hess scale.

Results: The average age found was 53.6 years old (min 28 to Max 92). The incidence was higher among women (3.6:1). Worse outcomes were observed in group A. The mortality rate was 20% in group A and zero cases in group B. Similar rate was found for rupture cases (20% in A group vs zero in B group). Morbidity was similar for both groups. The mean aneurismal size for A group was 6mm (ranging from 5 to 25mm) and 5.3mm (ranging from 3 to 10 mm) for B group.

Conclusions: Posterior communicating artery aneurysms occurred 3 to 4 times more frequently in women than man. Oculomotor palsy associated with severe headache were commonly related to posterior circulation aneurysms. Type II aneurysms (temporal) were the most frequently found in our study. The worst prognosis in cases with acute bleeding occurred with fetal variant circulation. Intratentorial aneurysms, mainly those with increased Hunt-Hess, have the worst prognosis. Infundibular aneurysms had the best results with surgical clipping.

Proudly powered by WordPress