Acute ischemic stroke and abnormal blood hemoglobin concentration

OBJECTIVES

This study examines whether low or high blood hemoglobin concentration (HGB) is associated with stroke severity, worse clinical outcomes, and poorer prognosis after acute ischemic stroke (AIS).

METHODS

This retrospective cohort study included data from the Ontario Stroke Registry on consecutive patients with AIS who were admitted between July 2003 and March 2008. We excluded patients taking anticonvulsants or iron supplement; patients with cancer, renal failure, history of gastro-intestinal or genitourinary bleeding, and pregnancy. Patients were divided into groups as follows: low HGB, normal HGB, and high HGB. Outcome measures included the frequency of greater degree of disability at discharge (modified Rankin score: 3-6), 7-day, 30-day and 90-day mortality, and length of stay in the acute stroke care hospital.

RESULTS

Hemoglobin levels higher than the upper limit of normal are associated with a greater disability at discharge (OR = 1.49, 95% CI: 1.03-2.15, P = 0.0331), and higher 30-day mortality (HR = 1.98, 95% CI: 1.44-2.74, P < 0.0001) after adjustment for major potential confounders. The Kaplan-Meier curves indicate that abnormal HGB levels are associated with higher mortality after AIS (P < 0.0001). HGB levels below the lower limit of normal are associated with longer lengths of stay in the acute care hospital (OR = 1.11, 95% CI: 1.02-1.22, P = 0.017). Elevated HGB was associated with greater neurological deficit on admission (OR = 1.45, 95% CI: 1.06-1.95, P = 0.0195).

CONCLUSIONS

Our results suggest that an elevated HGB on the initial admission is associated with more severe strokes, greater disability at discharge, and higher 30-day mortality after AIS. A low HGB on admission is associated with longer stay in the acute care hospital.

Management of anticoagulation following central nervous system hemorrhage in patients with high thromboembolic risk

SUMMARY BACKGROUND

Patients who present with central nervous system (CNS) hemorrhage while on anticoagulation (AC) for thromboembolic (TE) risk factors are a challenge to manage.

OBJECTIVE

We sought to inform decisions surrounding the timing and intensity of AC resumption by performing a systematic review.

METHODS

Three reviewers screened publications from Medline and EMBASE and extracted data. Hemorrhagic and TE adverse events that occurred subsequent to the index hemorrhage were recorded, as was their timing relative to presentation and covariates that might influence their occurrence.

RESULTS

Data were extracted from 63 publications detailing 492 patients; 7.7% of patients experienced hemorrhagic complications and 6.1% experienced TE complications. Hemorrhagic complications were more common within 72 h of presentation while TE complications were more common thereafter. Patients restarted on AC after 72 h were significantly more likely to have a TE complication (P = 0.006) and those restarted before 72 h were more likely to hemorrhage (P = 0.0727). Factors associated with re-hemorrhage included younger age, traumatic cause, subdural hematomas and failure to reverse AC. TE complications were more common in younger patients and those with spinal hemorrhage, multiple hemorrhages, and non-traumatic causes of the index hemorrhage. Re-initiation of AC at a lower intensity also significantly increased the risk of TE complications.

INTERPRETATION

Our results suggest that it may be prudent to re-initiate AC earlier than previously thought, with the timing and intensity modified based on predictors of TE and hemorrhagic complications. These findings must be explored in a prospective study because of limitations inherent to the analyzed studies.

Optimal treatment for severe neurogenic bowel dysfunction after chronic spinal cord injury: a decision analysis

BACKGROUND

When conservative management fails in patients with chronic spinal cord injury (SCI) and neurogenic bowel dysfunction, clinicians have to choose from a variety of treatment options which include colostomy, ileostomy, Malone anterograde continence enema (MACE) and sacral anterior root stimulator (SARS) implantation. This study employed a decision analysis to examine the optimal treatment for bowel management of young individuals with chronic refractory constipation in the setting of chronic SCI.

METHODS

A decision analysis was created to compare the four surgical strategies using baseline analysis, one-way and two-way sensitivity analyses, 'worst scenario' and 'best scenario' sensitivity analyses, and probabilistic sensitivity analyses. Quality-adjusted life expectancy (QALE) was the primary outcome.

RESULTS

The baseline analysis indicated that patients who underwent the MACE procedure had the highest QALE value compared with the other interventions. Sensitivity analyses showed that these results were robust.

CONCLUSION

The MACE procedure may provide the best long-term outcome in terms of the probability of improving bowel function, reducing complication rates and the incidence of autonomic dysreflexia, and being congruent with patients' preferences. The analysis was sensitive to changes in assumptions about quality of life/utility, and thus the results could change if more specific estimates of utility became available.

Localization of the superior laryngeal nerve during carotid endarterectomy

Knowledge of the topographic anatomy is essential to prevent iatrogenic damage of the superior laryngeal nerve (SLN) in carotid endarterectomy (CEA). The purpose of this study was to analyze the anatomic relationship between the SLN and carotid arteries in order to prevent iatrogenic nerve injury. Anatomic dissections similar to CEA were performed bilaterally in 50 fresh human adult cadavers. The topography of the SLN was analyzed regarding its relationship with the carotid arteries. Furthermore, the distance between the external branch of the SLN and the point of bifurcation of the common carotid artery (dCAB) was analyzed regarding effects of gender, ethnicity, individual stature and side of the neck. The SLN was always located adjacent and posterior to the carotid arteries.The dCAB ranged from 20.3 mm below the point of bifurcation of the common carotid artery to 50.9 mm above this level (average 10.3 mm above). Most dissections (75%) showed the external branch of the SLN emerging from behind the carotid artery above the arterial bifurcation; in only 10% of cases did this nerve emerge from the artery below that anatomic reference. Based on Student's t-test, there were no significant differences in the dCAB between genders ( P=0.237), ethnicities ( P=0.410) and sides of the neck ( P=0.872). Moreover, tall stature was not significantly correlated with a shorter dCAB (linear regression: R(2)=0.009, P=0.357). We conclude that most SLNs were located above the carotid artery bifurcation, but anatomic variations occurred in 25% of the dissections. The dCAB was unaffected by gender, ethnicity, individual stature and side of the neck.

Anatomical study applied to anesthetic block technique of the superior laryngeal nerve

BACKGROUND

The topography of the internal branch of the superior laryngeal nerve (ibSLN) was prospectively studied to evaluate the greater horn of the hyoid bone (ghHB) and the incisura of the thyroid cartilage (iTC) as anatomical repairs in laryngeal anesthetic block. Factors such as gender, ethnicity and side of the neck were also analyzed concerning their influence in the ibSLN position.

METHODS

One hundred neck dissections were performed in 50 human cadavers bilaterally identifying the ibSLN, the ghHB and iTC. The distance between the ghHB and ibSLN in the cranio-caudal direction (dHB), and the distance between the iTC and the ipsilateral thyrohyoid membrane ostium (dTC) were measured. Furthermore, the results were statistically analyzed according to ethnicity, gender and side of the neck.

RESULTS

The ibSLN was juxtaposed to the apex ghBH in 31 out of 100 dissections. The mean dHB was 2.4 mm, and mean dTC was 33.4 mm. The statistical analysis did not identify any significant difference regarding those distances between the groups in terms of ethnicity, gender and side of the neck.

CONCLUSION

The ibSLN was often dissected very close to the ghHB, and this result was not influenced by any factor studied. Therefore, the ghHB can be considered a good anatomical repair to localize the ibSLN in the local block of the larynx. Furthermore, the dTC could frequently be reached by routinely used nerve block needle. However, a few anatomical variations may occur, resulting in a low failure rate of this anesthetic procedure.

Biologic basis for the treatment of microscopic, occult well-differentiated thyroid cancer

BACKGROUND

Management of thyroid microcancer or occult well-differentiated thyroid cancer (OWDTC) is controversial. Our present study compared some clinical features of OWDTC and gross well-differentiated 10-mm thyroid carcinoma (GWDTC), which may offer a basis for treatment policy.

METHODS

From 1964 to 2000, 1000 patients underwent thyroidectomy for thyroid cancer. We randomly selected 428 cases for study in which node sampling was carried out in 88% of GWDTC and 60% of OWDTC and who were demographically comparable. All data were obtained by chart review and analyzed by chi-square test.

RESULTS

With the maximum limit of 10 mm for defining OWDTC, we found 113 such cases with a mean size of 6.1 mm and 315 GWDTC cases with a mean size of 27.6 mm. The incidence of metastatic nodal disease was 16.8% in OWDTC cases and 25.7% in GWDTC cases (P = .057). Distant metastases occurred in 1 of 113 (0.9%) cases of OWDTC and 11 of 315 (3.5%) cases of GWDTC (P = .149). After a mean follow-up time of 55.8 months, neck metastatic recurrent disease occurred in 3 of 113 (2.7%) cases of OWDTC and 7 of 315 (2.2%) cases of GWDTC (P = .770). OWDTC was found in 11.1% of the GWDTC group undergoing an operation. Multicentricity occurred in 31.9% of OWDTC cases and 35.9% of GWDTC cases (P = .447). No cause-specific death occurred.

CONCLUSIONS

One cannot be dogmatic in treatment of microcancer, but one is justified in extending similar treatment principles for OWDTC as in GWDTC, which in our center usually indicates near-total thyroidectomy and consideration for radioactive iodine ablation.

[Surgical treatment of infections involving arterial prosthesis in aorto-femoral position]

This article is to evaluate the results of surgical treatment of aorto-femoral graft infections. The records of 20 patients with aorto-femoral graft infections were reviewed. The patients were submitted mostly to a combination of surgical procedures. They were: a) conservative treatment; b) partial removal of the infected graft and c) total removal of the infected graft. The removal of the prosthesis, partial or total, was followed by a new arterial reconstruction in some patients. The final treatment was: total removal of the infected graft in 11 (55%) patients, total removal plus arterial reconstruction in six, partial removal in two and partial removal plus arterial reconstruction in one. The results of treatment were presented as the survival rate and the effective palliation (patient alive, lower limbs preserved and infection cured). The survival rates after one month, 12, 24, 36 and 48 months were respectively: 80%, 60%, 53%, 42% and 27%. The effective palliation rates after one month and after 48 months were respectively 50% and 27%. The highest effective palliation rate was obtained when the infected prosthesis was removed and a new arterial reconstruction performed. We conclude that the treatment of choice of aorto-femoral graft infections seems to be the total removal of the graft followed by new arterial reconstruction.