Surgical Strategy in Modification of the Transpetrosal Approach to Avoid Postoperative Venous Complications: A Report of 74 Consecutive Cases.

BACKGROUND: The transpetrosal approach is a complex skull base procedure with a high risk of complications, particularly caused by injury of the venous system. It is in part related to variability of blood outflow pathways and their distinctive patterns in each individual patient. OBJECTIVE: To evaluate outcomes and complications after skull base surgery with use of the petrosal approach modifications, which selection was based on the detailed preoperative assessment of venous drainage patterns. METHODS: Overall, 74 patients, who underwent surgery via the transpetrosal approach at our institution between 2000 and 2017, were included in this study. In all cases, the venous drainage pattern was assessed preoperatively and categorized according to the predominant blood outflow pathway into four types as previously suggested by Hacker: (1) sphenoparietal sinus (SpPrt), (2) sphenobasal vein (SpB), (3) sphenopetrosal sinus (SpPS), and (4) cortical. The blood outflow through the bridging petrosal vein and the vein of Labbé was also taken into consideration. In patients with SpPrt- and a cortical-type venous drainage, the transpetrosal approach was used in a standard way. In patients with SpB-type venous drainage, limited extradural anterior petrosectomy was combined with intradural anterior petrosectomy after dural opening, superior petrosal sinus transection, tentorial cutting, Meckel's cave opening, and trigeminal nerve mobilization. In patients with SpPS-type venous drainage, after standard petrosectomy, dural opening, and tentorial cutting, SpPS ligation was done followed by 2-week interval before staged definitive tumor resection. RESULTS: Gross total, near-total, and subtotal resection of the lesion (meningioma, 48 cases; retrochiasmatic craniopharyngioma, 11 cases; brain stem cavernoma, 7 cases; other tumors, 8 cases) was achieved in 30 (40.5%), 24 (32.4%), and 20 (27.0%) patients, respectively. Postoperative complications that were possibly related to venous compromise were noted in 18 patients (24.3%), but neither one was major. Of these 18 patients, 9 were symptomatic, but all symptoms-aphasia (4 cases), seizures (2 cases), and confusion (3 cases)-fully resolved after conservative treatment. Overall, 13 patients, including 4 symptomatic, had signal changes on T2-weighted brain MRI, which were permanent only in 3 cases (all asymptomatic). CONCLUSION: Our suggested surgical strategy can be applied to any type of the venous drainage pattern. Preoperative evaluation and intraoperative preservation of the blood outflow pathways are crucial means for safe and effective application of the transpetrosal approach.

Delayed primary retention suture for inset of vascularized submental lymph node flap for lower extremity lymphedema.

BACKGROUND: Vascularized lymph node transfer (VLNT) has become one of the effective surgical treatments for extremity lymphedema. This study was to evaluate the re-exploration and total complication rates of VLNT for lower extremity lymphedema between two different flap inset techniques. METHODS: Sixty-nine patients who underwent 74 submental VLNT transfers between 2008 and 2018 were retrospectively studied. Fifty-six flaps were inset using a new delayed primary retention suture (DPRS) technique and other 18 flaps using conventional interrupted sutures as the non-DPRS group. RESULTS: The overall flap success rate was 100%. The DPRS group was released at a mean of 1.7 ± 0.7 times and took a mean of 10.3 ± 3.3 days for wound closure. There were no statistical differences in demographics, mean symptom duration, and mean Cheng's Lymphedema Grading between two groups. Mean frequency of cellulitis of 2.5 ± 1.5 times/year in non-DPRS group was significantly greater than 1.4 ± 1.6 times/year in DPRS group (P = .01). The re-exploration and total complication rates were 5.4% and 7.1% in DPRS group, and 27.8% and 33.3% in non-DPRS group, respectively (P = .02 and .02, respectively). CONCLUSIONS: The DPRS technique is a safe, simple, and reliable method for insetting the submental VLNT, which statistically decreased the re-exploration and total complication rates.

The effect of histo-blood group ABO system transferase (BGAT) on pregnancy related outcomes：A Mendelian randomization study.

Protein level of Histo-Blood Group ABO System Transferase (BGAT) has been reported to be associated with cardiometabolic diseases. But its effect on pregnancy related outcomes still remains unclear. Here we conducted a two-sample Mendelian randomization (MR) study to ascertain the putative causal roles of protein levels of BGAT in pregnancy related outcomes. Cis-acting protein quantitative trait loci (pQTLs) robustly associated with protein level of BGAT (P < 5 ×10-8) were used as instruments to proxy the BGAT protein level (N = 35,559, data from deCODE), with two additional pQTL datasets from Fenland (N = 10,708) and INTERVAL (N = 3301) used as validation exposures. Ten pregnancy related diseases and complications were selected as outcomes. We observed that a higher protein level of BGAT showed a putative causal effect on venous complications and haemorrhoids in pregnancy (VH) (odds ratio [OR]=1.19, 95% confidence interval [95% CI]=1.12-1.27, colocalization probability=91%), which was validated by using pQTLs from Fenland and INTERVAL. The Mendelian randomization results further showed effects of the BGAT protein on gestational hypertension (GH) (OR=0.97, 95% CI=0.96-0.99), despite little colocalization evidence to support it. Sensitivity analyses, including proteome-wide Mendelian randomization of the cis-acting BGAT pQTLs, showed little evidence of horizontal pleiotropy. Correctively, our study prioritised BGAT as a putative causal protein for venous complications and haemorrhoids in pregnancy. Future epidemiology and clinical studies are needed to investigate whether BGAT can be considered as a drug target to prevent adverse pregnancy outcomes.

An aberrant venous channel mimicking the perilabyrinthine cells in the petrous bone of a patient with vestibular schwannoma: illustrative case.

BACKGROUND: Anatomical variations, such as high jugular bulbs and air cell development in the petrosal bone, should be evaluated before surgery. Most bone defects in the internal auditory canal (IAC) posterior wall are observed in the perilabyrinthine cells. An aberrant vascular structure passing through the petrous bone is rare. OBSERVATIONS: A 48-year-old man presented with a right ear hearing disturbance. Magnetic resonance imaging revealed a 23-mm contrast-enhancing mass in the right cerebellopontine angle extending into the IAC, consistent with a right vestibular schwannoma. Preoperative bone window computed tomographic scans showed bone defects in the IAC posterior wall, which ran farther posteroinferiorly in the petrous bone, reaching the medial part of the jugular bulb. The tumor was accessed via a lateral suboccipital approach. There was no other major vein in the cerebellomedullary cistern, except for the vein running from the brain stem to the IAC posterior wall. To avoid complications due to venous congestion, the authors did not drill out the IAC posterior wall or remove the tumor in the IAC. LESSONS: Several aberrant veins in the petrous bone are primitive head sinus remnants. Although rare, their surgical implication is critical in patients with vestibular schwannomas.

Management of Sigmoid Sinus Injury: Retrospective Study of 450 Consecutive Surgeries in the Cerebellopontine Angle and Intrapetrous Region.

BACKGROUND: The sigmoid sinus is the biggest obstacle when approaching the posterior fossa and temporal bone. Adequate sinus exposure is required to obtain a sufficient operative field, but sinus injury is a potentially life-threatening complication. OBJECTIVE: To present our experience of sigmoid sinus injury and its management during surgeries in the cerebellopontine angle and intrapetrous region, with operative videos. METHODS: A total of 450 consecutive surgeries (385 retrosigmoid and 65 transmastoid approaches) over a 4-yr period were retrospectively investigated, focusing on sigmoid sinus injury, its repair technique, and long-term patency of the sinus. RESULTS: Pinhole-sized bleedings were controlled sufficiently by bipolar coagulation or fibrin glue-soaked hemostatic fabric. For lacerations of smaller than 3 mm, the sinus wall was reconstructed by suturing. For larger or unsuturable holes, patching a Gore-Tex membrane on a fibrin glue sheet (without any suturing) was used for the reconstruction. Hemostatic agents were not used for large lacerations to avoid any potential risks of delayed sinus occlusion. Major sinus injury requiring suturing or Gore-Tex patching occurred in 13 cases (2.9%). The bleeding was immediately controlled without sinus clamping, and surgery was not discontinued owing to the injury in any of them. The patients had no postoperative symptoms associated with sinus injury. In all the reconstructed sinuses, patency was confirmed on magnetic resonance imaging at the final follow-up. CONCLUSION: Sigmoid sinus injury can be well managed with long-term patency by utilizing different repair techniques. Initial safe and adequate exposure around the injury site was essential for all of these repair procedures.

Combined Transpetrosal Approach With Preservation of Superior Petrosal Vein Drainage for a Cerebellopontine Angle Epidermoid Cyst Extending Into Meckel's Cave: 3-Dimensional Operative Video.

The combined transpetrosal approach enables wide exposure around the petroclival region by cutting the tentorium and superior petrosal sinus. We often choose this approach for removal of tumors ventral to the facial and vestibulocochlear nerves, such as petroclival meningioma and epidermoid cyst, because complete removal of the tumor under direct visualization is required to prevent its later recurrence, especially in young patients. Recent reports revealed anatomical variations of the drainage of the superior petrosal sinus, and dural incision considering preservation of the superior petrosal vein was proposed.1-3 This 3-dimensional video shows a patient with an epidermoid cyst, which was surgically treated using the combined transpetrosal approach, with consideration of the variation of the superior petrosal sinus and preservation of the drainage route of the superior petrosal vein. The video was reproduced after informed consent of the patient. The patient is a 31-yr-old woman who presented with a left cerebellopontine angle epidermoid cyst extending into Meckel's cave. The superior petrosal sinus was of the lateral type, draining only laterally into the transverse-sigmoid junction without medial connection with the cavernous sinus.1 The combined transpetrosal approach was performed with cutting of the superior petrosal sinus medial to the entry point of the superior petrosal vein, in order to preserve its drainage into the transverse-sigmoid junction. Meckel' cave was opened along its lateral margin, and tumor removal was accomplished, leaving only a minute part of the capsule strongly adhering to the neurovascular structures. The patient had no new permanent neurological deficits during follow-up. The figures in the video were modified from Matsushima et al1 by permission of the Congress of Neurological Surgeons.