Ultrasound-guided fascia iliaca compartment block in pediatric patients using a long-axis, in-plane needle technique: a report of three cases

Ultrasound guided fascia iliaca compartment block (FICB) has not been previously described in pediatric patients. Reported here is an ultrasound guided long axis, in-plane needle technique used to perform FICB in three pediatric patients undergoing hip or femur surgery. Postoperative assessment revealed nerve blockade of the lateral femoral cutaneous, femoral, and obturator nerves or no requirement for narcotics in the PACU. FICB using this ultrasound guided technique was easy to perform and provided postoperative analgesia for hip and femur surgical procedures within the presumed distribution of the lateral femoral cutaneous, femoral, and obturator nerves.     

Hydrogel coil-related delayed hydrocephalus in patients with unruptured aneurysms

OBJECT: Because of high recanalization rates associated with wide-necked intracranial aneurysms treated with bare platinum coils, hydrogel coils (HydroCoil, MicroVention, Inc.) have been developed. Hydrogel coils undergo progressive expansion once exposed to the physiological environment of blood and increase overall aneurysm filling. METHODS: The authors retrospectively reviewed their series of patients with unruptured aneurysms treated between 1998 and 2006 and who underwent placement of bare platinum and hydrogel coils for cerebral aneurysms. They examined the incidence of delayed hydrocephalus as related to coil type. In a subgroup of patients in which preand postprocedure CT and MR imaging studies were available, the authors quantitatively analyzed the ventricular size change after hydrogel coils were placed. RESULTS: Four of 29 patients treated with hydrogel coils developed symptomatic hydrocephalus 2-6 months after the intervention compared with 0 of 26 treated with bare platinum coils alone. The difference in ventricular size between the subgroups in which pre- and postprocedure imaging was performed was found to be statistically significant (p < 0.05). All 4 HydroCoil-treated patients in whom hydrocephalus developed required placement of a shunt. CONCLUSIONS: A 14% incidence (95% confidence interval 3.9-31.7%) of hydrocephalus in patients with unruptured aneurysm undergoing embolization with hydrogel coils was discovered. This incidence is much higher than previously reported. The mechanism by which hydrogel coils may induce hydrocephalus remains poorly understood.     

Gow-Gates technique: a pilot study for extraction procedures with clinical evaluation and review

The aim of this study was to compare the effectiveness of 2 different volumes of anesthetic solution for a premolar-molar extraction, and to determine the onset of complete mandibular conduction anesthesia via a Gow-Gates mandibular block. One operator performed 32 blocks with a 27-gauge needle on patients who required a dental extraction: 16 blocks using 1.8 mL of anesthetic solution, and 16 blocks using 3.6 mL of anesthetic solution. The parameters evaluated were frequency of successful anesthesia and onset of complete anesthesia. Significant differences (P < .005) were observed in the evaluation of volume: the 3.6 mL group yielded a higher success rate (82.5%) than the 1.8 mL group (17.5%). The onset of complete conduction anesthesia was achieved in 8 minutes by 56% of the subjects (9 of 16) with 3.6 mL and only one subject in 16 (6%) with 1.8 mL. A larger volume of anesthetic solution (3.6 mL) is required to achieve a higher success rate and a faster onset of action for a dental extraction without the use of reinforcement anesthesia. The volume of anesthetic solution is indirectly proportional to the onset of complete anesthesia. A premolar-molar extraction can be done, with 3.6 mL of anesthetic solution, in more than 50% of the patients 8 minutes after injection.     

Serum estradiol concentration as a predictor of death in critically ill and injured adults

BACKGROUND: Whereas animal models of sepsis demonstrate survival benefits for the pro-estrus state, human observational studies have failed to demonstrate a consistent survival advantage among female patients. Estrogen biosynthesis differs substantially in primate and non-primate animals, and estrogens have diverse immunologic actions. Estrogen concentrations are elevated in response to critical illness and injury (regardless of sex), and elevated concentrations of serum estradiol are associated with a higher mortality rate. Our objective was to determine the predictive ability and test characteristics of the serum estradiol concentration at 48 h in critically ill patients. METHODS: A prospective cohort study of surgical and trauma adult intensive care unit patients at two academic tertiary-care centers. Sex hormones (estradiol, progesterone, testosterone, prolactin, and dehydroepiandrosterone) and cytokines were assayed at 48 h, and the 28-day all-cause mortality rate was assessed. RESULTS: There was no difference in mortality rates between the sexes (survivors being male in 75.2% of cases vs. 76.0% in non-survivors; p = 0.43). The serum estradiol concentration was significantly elevated in non-survivors regardless of sex (median 18.7 pg/mL [interquartile range {IRQ} 9.99-43.6] in survivors and 40.7 pg/mL [IQR 9.99-94.8] in non-survivors; p < 0.001). The area under the receiver-operating characteristic (ROC) curve for serum estradiol was 0.64 (95% confidence interval [CI] 0.55, 0.72). The parameter with the largest ROC curve was the Acute Physiology and Chronic Health Evaluation (APACHE) II score (0.75; 95% CI 0.68, 0.82). A serum estradiol cut-point of 50 pg/mL was 48% sensitive and 80% specific in predicting death and classified the outcome of 76% of patients correctly. CONCLUSIONS: Serum estradiol concentration is a valuable prognostic tool and potential contributor to adverse outcomes of critically ill or injured surgical patients.     

Kidney stones during pregnancy: an investigation into stone composition

Kidney stones can be a source of considerable morbidity for pregnant women. Although there is a body of literature confirming that different stone compositions predominate for different age and sex cohorts, there have been no similar reports characterizing the nature of stone disease during pregnancy. We performed a multi-institutional study to define the composition of renal calculi diagnosed during pregnancy. We retrospectively reviewed the records from two stone referral centers of all patients diagnosed with a de novo kidney stone during pregnancy who underwent a procedure for the purpose of stone removal from June 2001 through September 2007. A total of 27 patients were identified, with a mean age of 26.8 years (range, 21-34). Twenty patients (74%) had no history of prior stone formation. Seven patients (26%) had previously formed stones, although none of these patients had a known kidney stone at the time they became pregnant. Stones were removed in the first, second, third trimester and immediately post-partum in 4, 52, 22, and 22% respectively. Stone removal was performed without complication in all cases. Analysis found that in 74% of all cases (20 patients) stones were composed predominantly of calcium phosphate (hydroxyapatite). In 26% of cases, (7 patients) the stones were composed predominantly of calcium oxalate. Of the seven patients with prior stone history, three patients had previously formed calcium phosphate stones and four patients had previously formed calcium oxalate stones. Calcium oxalate calculi are the most common stone in non-pregnant women of a comparable age as our subjects. However, our present data suggest that stones detected during pregnancy are most commonly composed of calcium phosphate (hydroxyapatite). Indeed, it is the minority of stones that are composed of calcium oxalate. Although the reason for this unusual preponderance of calcium phosphate calculi is unclear, physiologic alterations that occur during pregnancy may be influential.     

Cell membrane and mitotic markers show that the neonatal rat gubernaculum grows in a similar way to an embryonic limb bud

Aim/Background

How the gubernaculum guides the testis into the scrotum remains controversial, with various proposals from passive inversion to active growth. We aimed to determine if the gubernaculum contains an area of active proliferation, such as a “progress zone” in a growing embryonic limb bud, using a fluorescent cell membrane marker, 1,1′-didodecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate [DiIC₁₂(3)], to trace cell migration, and 5-bromodeoxyuridine (BUDR) (a thymidine analogue) as a mitotic marker.

Methods

Gubernacula were collected from neonatal male rats (n = 42, day 1-2, Sprague-Dawley) and cultured with calcitonin gene-related peptide (CGRP; 714 nmol/L). 1,1′-didodecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate-coated glass beads (diameter, 150-212 μm) were placed next to the bulb for the first 3 hours. Gubernacula were cultured for 3, 18, and 24 hours, then frozen sections cut and examined by confocal microscopy (wavelength, 549 nm). In a second experiment, pups not exposed to exogenous CGRP (n = 53, day 0, Sprague-Dawley) were injected intraperitoneally with BUDR (50 mg/kg of body weight); gubernacula were collected at 2, 48, 72, and 96 hours postinjection (PI), sectioned, and stained using immunohistochemistry to count the number of BUDR-positive cells per 100 cells (labeling index) in the bulb, cremaster, cord, and epididymis.

Results

After 24 hours' culture with CGRP, the bulb showed an oval region (diameter, 300 μm) of high fluorescence, and the cremaster region showed elongated cells migrating out of the bulb. When cultured without CGRP, the same oval region contained no fluorescence. In vivo BUDR labeling index increased in all areas until 48 hours postinjection and then decreased most rapidly in the bulb (P < .05), in the presence of endogenous CGRP from the genitofemoral nerve.

Conclusions

The rat gubernaculum contains a putative progress zone, such as in a growing limb bud, in the presence of CGRP. Cells migrate out of this zone to form cremaster muscle. We hypothesize that proliferation in the bulb elongates the gubernaculum, whereas proliferation of cremaster cells would increase gubernacular diameter. This brings to “life” the gubernaculum as an actively growing organ in contrast to the inert ligament connecting the testis to the scrotum portrayed in most anatomy textbooks.     

The anatomy of the cremaster muscle during inguinoscrotal testicular descent in the rat

Background

Extrapolation of rat testicular descent studies to humans has been criticized because of anatomical differences of the cremaster muscle. Human cremaster is described as a thin strip rather than a large, complete sac as in rats, which is proposed to be more important in propelling the testis during descent. This study investigated cremaster muscle anatomy and ontogeny in both normal and cryptorchid rat models.

Methods

Gubernacula from 4 groups of neonatal rats were sectioned longitudinally and transversely: normal Sprague-Dawley, capsaicin pretreated, flutamide pretreated, and congenital cryptorchid rats. Gubernacula were stained with hematoxylin-eosin, Masson trichrome, and desmin immunohistochemistry to study muscle development.

Results

Myoblasts are more numerous at the gubernacular tip, whereas the most differentiated muscle is proximal. Rat cremaster develops as an elongated strip rather than a complete sac derived from abdominal wall muscles. Flutamide and capsaicin pretreatment disrupts development.

Conclusion

Rat cremaster muscle develops as a strip, bearing close resemblance to human cremaster muscle, permitting extrapolation of cremaster function to human testicular descent. The cremaster muscle appears to differentiate from the gubernacular tip during elongation to the scrotum, and requires intact sensory innervation and androgen.     

Transduodenal local resection for low-risk group ampulla of vater carcinoma

BACKGROUND: Carcinoma of the ampulla of Vater has a more favorable prognosis, compared to other malignant tumors of the periampullary region, because it usually presents with symptoms in the early stage. However, treatment by local resection only of the ampullary carcinoma remains controversial. The aim of this study was to evaluate the treatment results of the ampulla of Vater carcinoma according to different types of operation in low-risk-group patients. METHODS: We retrospectively reviewed the medical records of 17 low-risk-group patients among a total of 102 patients with ampulla of Vater carcinoma who had underwent curative surgery from 1992 to 2002. All specimens were critically reviewed by a single expert pathologist, and the relationship between surgical outcomes and operation type was assessed. RESULTS: The low-risk group was comprised of 10 men and 7 women with a median age of 57.8 years. Thirteen of 17 patients underwent a pancreaticoduodenectomy (PD) or a pylorus preserving pancreaticoduodenectomy (PPPD), while 4 patients underwent a transduodenal local resection (TDLR). The operation time was significantly shorter in the TDLR group, compared to the PD or PPPD groups. Among the 17 patients, there was only 1 case of recurrence in the inguinal area 33 months after the pancreaticoduodenectomy. CONCLUSIONS: Transduodenal local resection is a comparable mode of operation for low-risk-group patients with Ampulla of Vater carcinoma. In particular, it is essential to evaluate the invasion depth in preoperative endoscopic ultrasonography, cell differentiation in preoperative biopsy, and positivity of resection margin accurately by using frozen section during the operation.     

A preoperative prognostic nomogram for solid enhancing renal tumors 7 cm or less amenable to partial nephrectomy

PURPOSE: Small renal masses are increasing in incidence. Most tumors 7 cm or less are treated with radical or partial nephrectomy but clinicians are increasingly relying on ablative therapies and observation for some small renal masses. We present novel nomograms that predict the likelihood of benign, likely indolent or potentially aggressive pathological findings based only on readily identifiable preoperative factors. MATERIALS AND METHODS: Information on all partial nephrectomies performed at a single institution was collected in an institutional review board approved registry. Using retrospectively collected data on all 862 patients who underwent partial nephrectomy for a single, solid, enhancing, clinical T1 (7 cm or less) tumor between 1999 and 2005 tumors were classified as benign or malignant. Grade 3 clear cell renal cell carcinoma, grade 4 renal cell carcinoma of any type and any renal cell carcinoma with vascular, fat or collecting system invasion were considered potentially aggressive. The likelihood of benign, likely indolent or potentially aggressive pathological findings was modeled using multivariable logistic regression models based on age, gender, radiographic tumor size, symptoms at presentation and smoking history. RESULTS: Of 862 small renal masses 20% were benign and 80% were malignant but only 30% of cancers (24% of small renal masses) were potentially aggressive. All 11 patients with systemic symptoms had cancer. The remaining 851 patients underwent further analysis. Factors that were most strongly associated with the likelihood of benign pathology were age, gender, tumor size and smoking history. A nomogram constructed to predict benign histology proved to be relatively accurate and discriminating (bootstrap corrected concordance index 0.644) and calibrated. Small renal masses in older men and younger women were more likely to be benign. With regard to differentiating indolent from potentially aggressive cancers, only advanced age was independently significant on multivariate analysis (p <0.005). The nomogram for this outcome performed with limited ability (concordance index 0.557). CONCLUSIONS: Clinical factors provide substantial predictive ability to predict benign vs malignant pathology for small renal masses amenable to partial nephrectomy. Although most of these small renal masses are benign or indolent, our ability to predict potentially aggressive cancer in this population remains limited.     

Duplex scan surveillance after carotid angioplasty and stenting: a rational definition of stent stenosis

OBJECTIVE: A duplex ultrasound (DUS) surveillance algorithm used after carotid endarterectomy (CEA) was applied to patients after carotid stenting and angioplasty (CAS) to determine the incidence of high-grade stent stenosis, its relationship to clinical symptoms, and the outcome of reintervention. METHODS: In 111 patients who underwent 114 CAS procedures for symptomatic (n = 62) or asymptomatic (n = 52) atherosclerotic or recurrent stenosis after CEA involving the internal carotid artery (ICA), DUS surveillance was performed 300 cm/s, diastolic velocity >125 cm/s, internal carotid artery stent/proximal common carotid artery ratio >4) involving the stented arterial segment prompted diagnostic angiography and repair when >75% diameter-reduction stenosis was confirmed. Criteria for >50% CAS stenosis was a PSV >150 cm/s with a PSV stent ratio >2. RESULTS: All 114 carotid stents were patent on initial DUS imaging, including 90 (79%) with PSV <150 cm/s (94 +/- 24 cm/s), 23 (20%) with PSV >150 cm/s (183 +/- 34 cm/s), and one with high-grade, residual stenosis (PSV = 355). During subsequent surveillance, 81 CAS sites (71%) exhibited no change in stenosis severity, nine sites demonstrated stenosis regression to <50% diameter reduction, and five sites developed velocity spectra of a high-grade stenosis. Angiography confirmed >75% diameter reduction in all six CASs with DUS-detected high-grade stenosis, all patients were asymptomatic, and treatment consisted of endovascular (n = 5) or surgical (n = 1) repair. During the mean 33-month follow-up period, three patients experienced ipsilateral, reversible neurologic events at 30, 45, and 120 days after CAS; none was associated with severe stent stenosis. No stent occlusions occurred, and no patient with >50% CAS stenosis on initial or subsequent testing developed a permanent ipsilateral permanent neurologic deficit or stroke-related death. CONCLUSION: DUS surveillance after CAS identified a 5% procedural failure rate due to the development of high-grade in-stent stenosis. Both progression and regression of stent stenosis severity was observed on serial testing, but 70% of CAS sites demonstrated velocity spectra consistent with <50% diameter reduction. The surveillance algorithm used, including reintervention for asymptomatic high-grade CAS stenosis, was associated with stent patency and the absence of disabling stroke.