Extravascular chest wall technetium 99m diethylene triamine penta-acetic acid: implications for the measurement of renal function during renography

Measurement of individual kidney glomerular filtration rate (IKGFR) from the gamma-camera technetium 99m diethylene triamine penta-acetic acid (^99mTc-DTPA) renogram requires a continuous measurement of arterial activity. This is usually based on a region of interest (ROI) placed over the cardiac blood pool on the posterior view, with the assumption of negligible contamination from activity in the extravascular space of the chest wall. By injecting a small dose of technetium 99m human serum albumin (HSA) before the^99mTc-DTPA in 12 patients undergoing routine renography, the contribution of extravascular activity to the total signal recorded over the cardiac blood pool was calculated to be 11.0% (SE 2.1%) 1.5 min after DTPA injection, rising to 35.1% (SE 2.5%) at 15 min. Subtraction of the time-activity curve recorded from a ROI of the same size over the right lung generated a pure blood signal as shown by almost identical HSA/DTPA signal ratios recorded in blood samples taken 5 min after HSA and 15 min after DTPA and from the gamma-camera at the corresponding times. The effect of using a cardiac blood pool time-activity curve uncorrected for extravascular activity was to overestimate IKGFR by an average factor of 1.17 (SE 0.03). Offprint requests to: A.M. Peters     

Hemifacial spasm caused by a tortuous recurrent perforating artery: A case report

IntroductionWhen the culprit vessel in hemifacial spasm (HFS) is hard to determine, this is a challenge in microvascular decompression (MVD) surgery. In such a situation, small arteries such as perforators to the brainstem might be suspected. But small arteries are omnipresent near the facial nerve root exit/entry zone (fREZ). How to decide whether a given small artery is responsible for HFS is unclear.MethodWe report a case with a previously unreported form of neurovascular impingement, in which the culprit was found to be the recurrent perforating artery (RPA) from the anterior inferior cerebellar artery (AICA). An aberrant anatomic configuration of the RPA was found intraoperatively, which we thought was responsible for generating focal pressure on the facial nerve.Case reportA 62-year-old woman presented with a 1-year history of paroxysmal but increasingly frequent twitching in her right face. MRI showed tortuosity of the vertebral artery and apparently marked neurovascular impingement on the asymptomatic left side, while only the right AICA could be implicated as the possible culprit. Hemifacial spasm was diagnosed based on the typical clinical manifestation, and MVD was performed. The pre-meatal segment of the AICA was found not to be impinging the facial nerve at any susceptible portion near the fREZ: root exit point, attached segment, or root detachment point. The real culprit was in fact the RPA. This occult culprit vessel was tortuous, forming a coil-shaped twist which was interposed between the facial nerve and the intermediate nerve near the root detachment point. Focal pressure atrophy of the nerve was clearly observed at the compressing site. The patient achieved total spasm relief immediately after surgery, and remained spasm-free at 1-year follow-up, without any postoperative complications.ConclusionMVD is the only curative treatment for hemifacial spasm, but with a failure rate of around 10%. Mistaking the real culprit has been reported to be the most likely reason for surgical failure. Therefore, intraoperative identification of atypical occult forms of vascular compression is of importance to improve surgical outcome. In the present case, the RPA formed a coil-shaped twist, which inflicted focal vascular compression causing hemifacial spasm. We recommend careful inspection of the recurrent perforating artery during MVD for HFS, and decompressing any such neurovascular impingement.     

Quality of life after hemifacial spasm surgery: French versions of the HFS-8 and HFS-30 questionnaires

ObjectivesThe aim of the present study was to assess quality of life before and after surgery for hemifacial spasm, in order to validate two specific quality of life scales translated in French. Surgical results and complications were reported.Material and methodsTwenty-three patients with hemifacial spasm treated by microvascular decompression were retrospectively included. The HFS-8 and HFS-30 quality of life scales were translated from English into French using a forward-backward method and implemented on patients at least one year after surgery.ResultsMedian HFS-8 and HFS-30 values were respectively 16 ± 12.5 (range: 8–20.5) and 38 ± 38.5 (range: 23–61.5) before surgery and 0.5 ± 4.5 (range: 0–4.5) and 5 ± 17.5 (range: 1–18.5) after surgery, showing significant improvement in quality of life (P < 0.001). The internal consistency of both scales was excellent (Cronbach's alpha > 0.9), and they were significantly correlated (Pearson coefficient = 0.95; 95% CI [0.91; 0.98]; P < 0.0001). Success rates were 83% and 91%, respectively, after primary and revision surgeries. Complications were transient with minor consequences in 80% of cases, but could impact quality of life when lasting.ConclusionsThese results support the validity of the French versions of HFS-8 and HFS-30. Microvascular decompression is a safe and effective treatment for hemifacial spasm, and these scales are reliable tools to assess postoperative quality of life.     

Intraoperative bleeding during endoscopic sinus surgery and microvascular density of the nasal mucosa

PurposeTo evaluate the correlation between quality of the surgical field, intraoperative bleeding during endoscopic sinus surgery (ESS) and the density of microvasculature of the nasal mucosa.Material/methodsNasal mucosa of 30 patients, operated for chronic rhinosinusitis, was biopsied to assess expression of CD34 antigen on vascular endothelium. Quality of surgical field was evaluated with Fromm-Boezaart scale at mean arterial pressure (MAP) of 70–80 mmHg. If at this MAP surgical field quality was not satisfactory further reduction of hemodynamic parameters was performed until ‘bloodless surgical field’ (grade 2 or lower) was achieved. The rate of intraoperative bleeding was calculated from the ratio of total blood loss and the operative time. The extent of the disease was assessed according to computed tomography findings using Lund-Mackay staging system.ResultsSignificant positive correlation (Spearman correlation test; p < 0.05) was found between CD34 antigen expression and quality of surgical field at MAP between 70 and 80 mmHg as well as the rate of intraoperative bleeding. More intense reduction of MAP was necessary to achieve ‘bloodless surgical field’ in patients with high CD34 expression than in those with moderate and low expression. Lund-Mackay score correlated with quality of surgical field but not with the rate of intraoperative bleeding.ConclusionDuring ESS, it is microvascular density of the nasal mucosa rather than the extent of the disease that contributes to the intensity of intraoperative bleeding, although both factors negatively influence the quality of surgical field.     

Involvement of PKCα–MAPK/ERK-phospholipase A2 pathway in the Escherichia coli invasion of brain microvascular endothelial cells

Escherichia coli K1 is the most common Gram-negative organism that causes neonatal meningitis following penetration of the blood–brain barrier. In the present study we demonstrated the involvement of cytosolic (cPLA₂) and calcium-independent phospholipase A₂ (iPLA₂) and the contribution of cyclooxygenase-2 products in E. coli invasion of microvascular endothelial cells. The traversal of bacteria did not determine trans-endothelial electrical resistance (TEER) and ZO-1 expression changes and was reduced by PLA₂s siRNA. cPLA₂ and iPLA₂ enzyme activities and cPLA₂ phosphorylation were stimulated after E. coli incubation and were attenuated by PLA₂, PI3-K, ERK 1/2 inhibitors. Our results demonstrate the role of PKCα/ERK/MAPK signaling pathways in governing the E. coli penetration into the brain.