Natural Course and Prognosis of Primary Spinal Glioblastoma: A Nationwide Study

BACKGROUND AND OBJECTIVES

Primary spinal glioblastoma is extremely rare. The dramatic neurological deterioration and unresectability of primary spinal glioblastoma makes it a particularly disabling malignant neoplasm. Since it is a rare and heterogeneous disease, the assessment of prognostic factors remains limited.

METHODS

Primary spinal glioblastomas were identified from The French Brain Tumor Database and the Club de Neuro-Oncologie of the Société Française de Neurochirurgie retrospectively. Inclusion criteria were age ≥ 18 years at diagnosis, spinal location, histopathological diagnosis of newly glioblastoma according to the 2016 World Health Organization classification, and surgical management between 2004 and 2016. Diagnosis was confirmed by a centralized neuropathological review. The primary outcome was overall survival. Therapeutic interventions and neurological outcomes were also collected.

RESULTS

Thirty-three patients with an histopathologically confirmed primary spinal glioblastoma (median age 50.9 years) were included (27 centers). The median overall survival (OS) was 13.1 months (range 2.5-23.7) and the median progression-free survival was 5.9 months (range 1.6-10.2). In multivariable analyses using Cox model, ECOG PS at 0-1 was the only independent predictor of longer OS [Hazard Ratio: 0.13, 95%CI 0.02-0.801; p=0.02], whereas a Karnofsky PS score <60 [Hazard Ratio: 2.89, 95%CI 1.05-7.92; p=0.03] and a cervical anatomical location [Hazard Ratio: 4.14, 95%CI 1.32-12.98; p=0.01] were independent predictors of shorter OS. The ambulatory status (Frankel D-E) [Hazard Ratio: 0.38, 95%CI 0.07-1.985; p=0.250] was not an independent prognostic factor while the concomitant standard radiochemotherapy with temozolomide (Stupp protocol) [Hazard Ratio: 0.35, 95%CI 0.118-1.05; p=0.06] was at the limit of significance.

DISCUSSION

Preoperative ECOG PS, Karnofsky PS score and the location are independent predictors of overall survival of primary spinal glioblastomas in adults. Further analyses are required to capture the survival benefit of concomitant standard radiochemotherapy with temozolomide.

SleepNet: automated sleep analysis via dense convolutional neural network using physiological time series

OBJECTIVE

In this work, a dense recurrent convolutional neural network (DRCNN) was constructed to detect sleep disorders including arousal, apnea and hypopnea using polysomnography (PSG) measurement channels provided in the 2018 PhysioNet Challenge database.

APPROACH

Our model structure is composed of multiple dense convolutional units (DCU) followed by a bidirectional long-short term memory (LSTM) layer followed by a softmax output layer. The sleep events, including sleep stages, arousal regions and multiple types of apnea and hypopnea, are manually annotated by experts, which enables us to train our proposed network using a multi-task learning mechanism. Three binary cross-entropy loss functions, corresponding to sleep/wake, target arousal and apnea-hypopnea/normal detection tasks, are summed up to generate our overall network loss function that is optimized using the Adam method. Our model performance was evaluated using two metrics: the area under the precision-recall curve (AUPRC) and the area under the receiver operating characteristic curve (AUROC). To measure our model generalization, 4-fold cross-validation was also performed. For training, our model was applied to full night recording data.

MAIN RESULTS

Finally, the average AUPRC and AUROC values associated with the arousal detection task were 0.505 and 0.922, respectively, on our testing dataset. An ensemble of four models trained on different data folds improved the AUPRC and AUROC to 0.543 and 0.931, respectively.

SIGNIFICANCE

Our proposed algorithm achieved the first place in the official stage of the 2018 PhysioNet Challenge for detecting sleep arousals with an AUPRC of 0.54 on the blind testing dataset.

French-Canadian linguistic validation of the NIH Chronic Prostatitis Symptom Index

INTRODUCTION

The NIH Chronic Prostatitis Symptom Index (CPSI) is recommended in the clinical evaluation of men with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS). However, its use is not possible in French speakers, as it has not been validated in this population. We performed a linguistic validation of the CPSI.

METHODS

Linguistic translation followed the forward-backward-forward technique and relied on professional medical translators, bilingual health professionals, and patient input. Along with the SF-12, the translated version was administered to a convenience sample of men presenting for pre-vasectomy visits (controls) and to consecutive patients with established CP/CPPS (cases). Men with CP/CPPS were subsequently asked to complete a 14-day retest questionnaire. Psychometric testing addressed standard reliability and validity characteristics.

RESULTS

Thirty-six cases and 38 controls with respective mean ages of 46.5 and 44.0 years participated and 33 (91.2%) cases completed the retest questionnaire. Pain (p<0.001), urinary (p<0.001) and quality-of-life (QOL) scale (p<0.001) score means differed between cases and controls. For the same scales, Cronbach's alphas for cases were respectively 0.70, 0.72 and 0.79 versus 0.80, 0.57, and 0.88 for controls. The retest product-moments were 0.83 for pain, 0.55 for urinary, and 0.83 for QOL scales. In cases, strong correlation was noted between QOL and pain scales (r=0.7), and between urinary and pain scales (r=0.6), versus moderate correlation between QOL and urinary scales (r=0.4). Negative correlation was recorded between CPSI scales and SF-12 scales, which ranged from -0.2 to -0.4.

CONCLUSIONS

When applied to CPPS and control subjects, the French Canadian CPSI translation demonstrates excellent discriminant properties. Moreover, its reliability and validity characteristics confirm the qualities of the CPSI as a standard evaluative tool for men with CPPS.

Intracavernosal alprostadil is effective for the treatment of erectile dysfunction in diabetic men

The efficacy and safety of intracavernosal alprostadil was evaluated for the treatment of erectile dysfunction in men with type I or type II diabetes mellitus. This was an open-label, flexible dose-escalating study involving 336 men (77% of whom were Asian/Oriental) enrolled by 15 centres in Australia, Canada and seven countries in Asia. The effective alprostadil dose, ie the dose producing penile rigidity adequate for intercourse and lasting up to 60 min, was established by titration at the clinic prior to entry into the 6 month self-treatment home phase. All men were fully trained in the self-injection technique before entry into the home phase. Efficacy and safety were assessed using patient and partner diaries and by interview at clinic visits during the titration phase and after 1, 3 and 6 months of treatment. An effective home dose was established by titration for 94% of the 336 men (median dose 20 microg, range 2.5-60 microg). Of 278 (83%) men who entered the home phase, 277 men (247 with type II diabetes and 30 with type I diabetes) had evaluable data for alprostadil dosage and clinical response. During the home phase, a satisfactory erectile response was achieved after 99% of injections, and the median alprostadil dose remained unchanged. The initial home dose and clinical response were similar in type I and type II diabetic men. Treatment was generally well tolerated with a low incidence of penile pain (24%) In conclusion, intracavernosal alprostadil was effective and well tolerated in type I and type II diabetic men with erectile dysfunction of mixed aetiology.

Extensive F-18 FDG uptake in metastatic spindle cell carcinoma of the lung

A 77-year-old man with stage IIB squamous cell carcinoma of the lung underwent right upper lobectomy. One month later he was examined for right chest pain, dyspnea, cough, and weakness. A roentgenogram showed nondiagnostic diffuse opacification of his right lung cavity. An F-18 FDG positron emission tomographic (PET) study revealed extensive uptake in the right pleural area, left adrenal gland, right axilla, and soft tissues consistent with extensive local recurrence and metastatic disease. Biopsy of a right chest soft tissue lesion showed spindle cell carcinoma, a rare variant of squamous cell carcinoma.

Superiority of iodine-123 compared with iodine-131 scanning for thyroid remnants in patients with differentiated thyroid cancer

PURPOSE

Iodine-123 is a pure gamma emitter and has excellent characteristics for imaging with modern scintillation cameras. The goal of this study was to compare the performance of I-123 and I-131 as imaging agents for whole-body scanning in patients with differentiated thyroid cancer undergoing ablation for thyroid remnants after initial surgery.

METHODS

Fourteen patients with differentiated thyroid cancer who had undergone near-total thyroidectomy and had serum thyroid-stimulating hormone levels greater than 40 mU/I underwent diagnostic scanning 5 hours after administration of 48 to 56 MBq (1.3 to 1.5 mCi) I-123 and 48 hours after administration of 111 MBq (3 mCi) I-131. After receiving ablative I-131 therapy, they also underwent whole-body planar imaging 7 days later. The diagnostic I-123 and I-131 scans were compared with each other and with the post-therapy images by two nuclear medicine physicians and one endocrinologist.

RESULTS

The diagnostic scans revealed 35 foci in the thyroid bed and neck. The I-123 images showed all 35 foci, but only 32 of the 35 foci (91 %) were seen on the I-131 scans. The findings of pre- and post-therapy scans were concordant in 11 of 13 patients, and the same general sites of uptake (left and right thyroid bed, midline) were revealed on both sets of images. In one patient, a focus seen on the diagnostic I-123 and I-131 images was not visualized on the post-therapy scan and was thought to represent possible stunning. An additional area of uptake in the lower right neck and upper mediastinum was present on the post-therapy scan of another patient, but it was not seen on diagnostic images.

CONCLUSION

These results show improved quality of imaging with 50 MBq (1.5 mCi) I-123 compared with 111 MBq (3 mCi) I-131 for whole-body scanning in patients with differentiated thyroid cancer undergoing thyroid remnant ablation. I-123 imaging may prove to be the preferred procedure in such settings in patients with differentiated thyroid cancer.

N-(n-Benzylpiperidin-4-yl)-2-[18F]fluorobenzamide: a potential ligand for PET imaging of breast cancer

N-(N-Benzylpiperidin-4-yl)-2-[(18)F]fluorobenzamide (2), a potential ligand for PET imaging of sigma receptor, has been found to be a potential agent for detection of breast cancer. In vivo studies in severe combined immunodeficient (SCID) mice bearing MDA-MB231 tumors showed that the uptake of compound 2 in these tumors was high (3.8%/g); the ratios of tumor/muscle and tumor/blood were 6.2 and 7.0, respectively, at 1 h postinjection. Pretreatment of SCID mice with haldol increased the uptake of compound 2 in blood, muscle, and other well-perfused organs while decreasing its uptake in tumors. The ratios of tumor/muscle and tumor/blood decreased from 6.2 and 7.0 to 1.3 and 1.1, respectively, at 1 h postinjection. At 2 h postinjection, the ratios of tumor/muscle and tumor/blood decreased from 4.9 and 7.8 to 1.4 and 1.4, respectively. The tumor uptake of compound 2 in SCID mice bearing primary tumor explants from a human breast cancer patient was lower than that in MDA-MB231 tumors (1.66%/g versus 3.78%/g), and the ratios of tumor/muscle and tumor/blood were 3.5 and 3.7, respectively, at 1 h postinjection. These results suggest that compound 2 may be a potential ligand for PET imaging of breast cancer.

Can the standardized uptake value characterize primary brain tumors on FDG-PET?

The aim of this study was to evaluate the usefulness of measuring the standardized uptake value (SUV) in primary brain tumors on fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) scans. Two groups of patients were studied. Whole-brain glucose cerebral metabolic rates (wCMRs) and SUVs were obtained in 20 normal subjects. Twenty-seven patients with histology-proven malignant primary CNS tumors (high-grade gliomas n=22, primitive neuroectodermal tumors n=3, ependymomas n=2) were also studied. The degree of FDG uptake was assessed by visual inspection and thereafter regions of interest were placed over the lesion, the contralateral cortex and white matter and the whole brain. Average (avg) and maximum (max) pixel values were determined in each site. Based on these measurements, SUV, tumor to cortex (T/C) and tumor to white matter (T/WM) activity ratios were calculated. There was no correlation between wCMRs (4.55+/-0.36 mg min(-1) 100 g(-1)) and wSUVs (5.41+/-0.43) in the normal subjects (r=0.18, P=0.45). In the second group, 17 lesions were described as definitely and seven as probably malignant. However, SUVs in these tumors and in the contralateral cortex were not significantly different. Although the SUVs were generally higher in the tumor than in the contralateral white matter, there was a significant overlap between the values. The range of the SUVs was wide: 2.54-11.8 for the tumors, 2.98-9.96 for the cortex and 1.87-6.76 for the white matter. SUVs in the normal cortex were negatively correlated with blood glucose level at the time of the injection. SUVs in the whole brain and in the cortex were lower in patients previously treated by irradiation, even months after completion of the treatment. No correlation was detectable between any of the SUVs and the age of the patients, tumor type, time post injection, use of dexamethasone, patient weight, dose injected and visual score. With cutoff levels of 1.5 for T max/WM and 0.6 for T max/C, the sensitivity of the activity ratios was 74% and 96% respectively. In conclusion, SUVs do not correlate with CMRs across subjects and appear to be of limited value in characterizing brain tumors. Visual assessment and measurement of the activity ratios currently remain the most reliable methods of analysis.

Dual time point fluorine-18 fluorodeoxyglucose positron emission tomography: a potential method to differentiate malignancy from inflammation and normal tissue in the head and neck

Fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) studies imaging FDG PET imaging is used to detect and stage head and neck cancers. However, the variable physiologic uptake of FDG in different normal structures as well as at inflammatory sites may either obscure a tumor focus or be falsely interpreted to represent tumor activity. Twenty-one patients (9 men, 12 women, median age 59) were scanned serially at two time points, one at 70 min (range 47-112) and the second at 98 min (77-142) after the intravenous injection of 4.3 MBq/kg of FDG. The mean interval between emission scans was 28 min (13-49). Transmission scans were performed and regions of interest (ROIs) were overlayed on the fully corrected images. Standardiued uptake values (SUVs) were generated for the cerebellum, tongue, larynx, every lesion, and a matched contralateral site. Follow-up and pathologic studies revealed 18 squamous cell carcinomas and nine inflammatory or infectious lesions. Tumor SUVs were 4.0+/-1.6 (mean +/- SD) for the first scan and 4. 5+/-2.2 for the second scan. Contralateral SUVs were 1.2+/-0.5 and 1. 1+/-0.5 for the two scans. Tumor SUVs increased by 12%+/-12% as compared with a 5%+/-17% decrease for contralateral sites (P<0.05). SUVs for inflammatory sites (2.0+/-0.7 and 2.0+/-0.9), cerebellum (4. 2+/-1.3 and 4.3+/-1.4), tongue (1.8+/-0.4 and 1.9+/-0.5) and larynx (1.5+/-0.6 and 1.5+/-0.6) remained constant over time (+0.6%, +2.8%, +1.4%, and -2.4%; P<0.05 when compared with tumor SUV changes). The ratio tumor/contralateral SUV increased by 23%+/-29% over time while this ratio for inflamed sites increased by only 5%+/-15% (P=0.07). The time interval between scans correlated with increase in SUV for tumors (r=0.55, P<0.05) but not for any of the other ROIs. Separation was superior when studies were performed more than 30 min apart (P<0.05). These preliminary data suggest that dual time point imaging compatible with a clinical study protocol is helpful in differentiating malignant lesions from inflammation and normal tissues, especially when separated by a sufficient time interval.

Detection of recurrent head and neck squamous cell carcinomas after radiation therapy with 2-18F-fluoro-2-deoxy-D-glucose positron emission tomography

OBJECTIVES/HYPOTHESIS

Fluorodeoxyglucose positron emission tomography (FDG-PET) has been proposed as a sensitive method to diagnose and stage various malignancies. We assessed the efficacy of FDG-PET imaging in distinguishing tumor persistence/recurrence from posttreatment changes following radiation therapy for squamous carcinomas of the head and neck

STUDY DESIGN

Retrospective analysis of FDG-PET results compared with biopsy results or outcome, or both.

METHODS

Twenty-eight patients who had undergone radiation therapy with or without surgery for treatment of squamous cell carcinoma were studied with FDG-PET imaging. There was clinical suspicion for recurrence in each patient, but no obvious mass or lesion to biopsy was found on physical examination or anatomic imaging. The results of FDG-PET imaging were compared with those of biopsy or clinical follow-up of at least 6 months, or both.

RESULTS

FDG-PET imaging was positive in 13 patients, and the presence of active disease was confirmed in 12. Two thirds of the 12 received further cancer treatment. There were 15 negative FDG-PET images. Thirteen of these were confirmed true-negative images, but two studies were false-negative images. The sensitivity and specificity of FDG-PET were 86% and 93%, respectively, with positive and negative predictive values of 92% and 87%, respectively. The overall accuracy was 89%.

CONCLUSION

FDG-PET imaging is a useful modality to distinguish tumor persistence/recurrence from radiation-induced tissue changes in the neck following treatment for head and neck cancer. FDG-PET can identify patients who may benefit from further treatment, and may lead to improved outcome for individual patients.

N-(N-benzylpiperidin-4-yl)-2-[18F]fluorobenzamide: a potential ligand for PET imaging of sigma receptors

Four nitro- and fluorobenzamides (1-4) have been synthesized in good yields from nitro- and fluoro-substituted benzoyl chloride with 4-amino-1-benzylpiperidine. In vitro studies showed that these compounds have high affinities to sigma receptors. N-(N-Benzylpiperidin-4-yl)-2-fluorobenzamide (3), in particular, bound to sigma receptors with high affinity (Ki = 3.4 nM, guinea pig brain membranes) and high selectivity (sigma-2/sigma-1 = 120). It was, therefore, labeled with 18F and evaluated as a sigma receptor radioligand. N-(N-Benzylpiperidin-4-yl)-2-[18F]fluorobenzamide (3a) was synthesized in one step by nucleophile substitution of the 2-nitro precursor (1) with [18F]fluoride in DMSO at 140 degrees C for 20 min followed by purification with HPLC in 4-10% yield (decay corrected). The synthesis time was 90 min and the specific activity was 0.4-1.0 Ci/mumol. Tissue distribution in mice revealed that the uptakes of 3a in the brain, heart, liver, lungs, spleen, kidneys and small intestine were high, and the radioactivity in these organs remained constant from 60 to 120 min post-injection. The radioactivity in the bone did not significantly increase, suggesting in vivo defluorination may not be the major route of metabolism of 3a in mice. Blocking studies with haloperidol in rats indicated that the uptake of compound 3a in the rat brain was selective to haloperidol-sensitive sigma sites. These results suggest that compound 3a is a potent sigma receptor radioligand and may be a potential ligand for PET imaging of sigma receptors in humans.

[Ureteroscopy versus in situ extracorporeal shockwave lithotripsy in the treatment of calculi of the distal ureter]

In a retrospective study from a unique center (St. Luc Hospital, Montreal) stone clearance of 88 consecutive distal ureteral calculi (below pelvic brim) treated by extracorporeal shock wave lithotripsy in situ were compared to a group of 94 distal ureteral calculi treated by ureteroscopy during the same period. Our results show 84% success rate for ureteroscopy which is clearly superior than 58% stone clearance rate at 3 month follow-up for ESWL Success rate was influenced by stone size in the ESWL group but not in the ureteroscopy group. This study reveals similar success rate for calculi smaller than 6 mm but for larger calculi, success rate of ureteroscopy is significantly superior.

Role of penile vascular injury in erectile dysfunction after radical prostatectomy

OBJECTIVE

To investigate the cause of erectile dysfunction after nerve-sparing radical prostatectomy for clinically localized adenocarcinoma of the prostate (stage A or B).

PATIENTS AND METHODS

Erectile function was evaluated in 20 patients, mean age 65 years (range 44-74), both pre-operatively and 1 year after surgery by intracavernosal injection of a vasoactive agent (papaverine hydrochloride or prostaglandin E1) and pulsed Doppler ultrasonography. The degree of erection, the size of the cavernosal artery and penile arterial blood flow velocity were assessed.

RESULTS

Results revealed that the decreased response to intracavernosal injection of a vasoactive agent was associated with a significant reduction in both the diameter and velocity of blood flow within cavernosal arteries in 40% of patients after surgery. The pathological stage of the tumour did not correlate with the degree of vascular injury.

CONCLUSION

We conclude that post-prostatectomy impotence is multifactorial but vascular injury plays a substantial role.

Calcitonin gene-related peptide: possibly neurotransmitter contributes to penile erection in monkeys

The distribution of calcitonin gene-related peptide (CGRP) immunoreactivity in the cavernous tissue and the erectile response to intracavernous injection of CGRP was investigated in 7 monkeys. Intracavernous CGRP increased cavernous arterial flow and induced cavernous smooth muscle relaxation and venous outflow occlusion. Intracavernous injection of CGRP antibody did not significantly change the erectile response to cavernous nerve stimulation. Histologic staining for CGRP immunoreactivity showed nerve fiber-like staining within the cavernous arterial wall and the cavernous smooth muscles. These data suggest that CGRP may contribute to penile erection in monkeys.

Effect of intracavernous simultaneous injection of acetylcholine and vasoactive intestinal polypeptide on canine penile erection

We investigated the effects of intracavernous injection of a combination of acetylcholine (ACh) and vasoactive intestinal polypeptide (VIP) on the erectile response in eleven adult male dogs. The minimum dose of ACh which increased the intracavernous pressure in eight dogs varied from 0.2 to 40 micrograms, and the minimum dose of VIP varied from 0.2 to 5 micrograms. When the minimum doses of ACh and VIP were injected simultaneously, a strong increase of intracavernous pressure (the mean increase was 102 cm. H2O from the baseline level) and a sustained erection (mean 5 min.) were observed in all eight dogs. The effect of simultaneous injection of both drugs was not additive but synergistic. Pretreatment with VIP-antibody and atropine intracavernously suppressed the erectile response induced by cavernous nerve stimulation. VIP may increase the affinity of muscarinic receptors for ACh in canine corpus cavernosum because pretreatment with atropine alone before the simultaneous injection of ACh and VIP completely abolished the effect of the combination. We conclude that ACh and VIP may play a cooperative role in canine penile erection.

Perineal pudendal neurotomy versus selective neurotomy of the S2 somatic contribution to the pudendal nerve. Effects on sacral-root-stimulated bladder and urethral responses in the dog

In 10 dogs that underwent bilateral electrode implantation on the S2 ventral root, 5 then underwent a bilateral total perineal neurotomy of the pudendal nerve (group A) at 3 months and 5 bilateral division of the S2 somatic contribution to the pudendal nerve (group B). The effects of these 2 types of neurotomy on the bladder and urethral responses to electrostimulation were compared after another 3 months. In group A, the proximal and mid-urethral responses decreased significantly [69.1% (p = 0.004) and 79.6% (p = 0.002), respectively]. A decrease in bladder response [26% (p = 0.089)], although not significant, was also found. In group B, the decrease in the proximal urethral response was significant [67.8% (p = 0.012)]; the mid-urethral response (56.8%) was not statistically significant (p = 0.134). The bladder response decreased by 73.6% (p = 0.034). Thus, although pudendal neurotomy can be effective in reducing the outlet resistance, the pudendal nerve may have an important role in the regulation of micturition in the dog. Preoperative testing of the effect of a pudendal neurotomy by temporary nerve blocks is warranted to avoid undesirable side effects such as a decrease in bladder excitability.

Penile detumescence: characterization of three phases

In 22 dogs in which erection was induced by cavernous nerve stimulation, we analyzed the intracavernous pressure changes during detumescence without and with acute clamping of the aorta or electrostimulation of the lumbar sympathetic chains. Additionally, the degree of venous outflow obstruction was assessed by saline perfusion of the cavernous body during aortic occlusion. Detumescence had three distinct phases: an initial phase exhibiting a small pressure increase; a second phase showing a slow pressure decrease; and a third phase in which a fast decrease occurred. The first phase was abolished by aortic clamping, whereas the other phases were not significantly affected. Sympathetic stimulation abolished or prevented the second phase. Perfusion of the cavernous body during the second phase resulted in a pressure rise to off-scale values; however, when initiated during the terminal phase or in the nonstimulated penis, the pressure increase was slight. Our study indicates that the arterial flow rate influences the duration of the first phase of detumescence and that venous drainage is completely restored in the third phase. Furthermore, sympathetic stimulation causes an almost immediate full restoration of venous drainage, as cavernous perfusion initiated with an intracavernous pressure about twice as high as without sympathetic stimulation failed to increase pressure to off-scale values.

The sympathetic role as an antagonist of erection

The effects of the lumbar and pelvic sympathetic system on penile erection were studied in a canine model. Erection was induced by cavernous nerve stimulation and detumescence by sympathetic trunk stimulation. Erection induced by cavernous nerve stimulation normally subsides slowly. After discontinuation of electrical stimulation the intracavernous pressure drops within a mean of 291 s to 50% and after a mean of 372 s to 10% of the highest level. However, stimulation of the sympathetic trunk at the level of L4-S1 applied directly after discontinuation of cavernous nerve stimulation accelerated this drop of intracavernous pressure significantly: to 50% after a mean of 19 s and to 10% after a mean of 36 s. If stimulation of the sympathetic trunk was initiated 20 s before cavernous nerve stimulation, the pressure rise was aborted completely. Neurostimulation of the hypogastric nerves alone or in combination with cavernous nerve stimulation did not change the intracavernous pressure. These results were not altered after neurotomy of the pudendal or hypogastric nerves. The main pathway of the fibers from the sympathetic trunk to the penis seems to run via the pelvic plexus. The stimulation voltage and frequency to induce erection or detumescence were equivalent. Our results suggest that an elevated central sympathetic tone may be one of the causes of psychogenic impotence.

Repeat hepatic resection for primary and metastatic carcinoma of the liver

During the last 15 years, 19 patients underwent repeated hepatic resections for malignant lesions of the liver. The first hepatic resection had been performed four to 40 months earlier for treatment of hepatocellular carcinoma (nine patients) or hepatic metastases (ten patients), eight of which were of colorectal origin. Repeat resection was an extensive hepatectomy in six, a segmentectomy in six and a local excision in seven. In one patient, three wedge resections and, finally, hepatic transplantation were subsequently performed after an initial extended right lobectomy. The operative mortality rate was 5.2 per cent. The three year actuarial survival rate was 64 per cent after the second resection.

Synchronized electrical stimulation of the sympathetic and parasympathetic innervation of the bladder: facilitation of the initiation of micturition in the dog

To improve the quality of bladder contractions induced by parasympathetic stimulation and to facilitate the initiation of voiding, we investigated the effect of sympathetic stimulation on the parasympathetic innervation of the bladder in 12 dogs. For the sympathetic system, the lumbar sympathetic trunks were electrically stimulated; for the parasympathetic system, either the pelvic nerve or the ventral root of S2 was stimulated. With voltages at or just above the threshold for achieving a measurable effect on bladder pressure, stimulation of the sympathetic system or the pelvic nerve alone did not lead to voiding, and sacral root stimulation alone elicited voiding in only 7.4 per cent of stimulations. However, when the same stimulus parameters were used for synchronous stimulation, the voiding process was facilitated when sympathetic stimulation was begun five to 10 seconds before parasympathetic stimulation. When the pelvic nerve was used, voiding resulted in 77.7 per cent of stimulations and the bladder was emptied by a mean of 68.7 per cent; with S2 ventral root stimulation, voiding resulted in 83.3 per cent of stimulations and the bladder was emptied by 59.7 per cent. The facilitory effect of sympathetic stimulation was not abolished when the sympathetic trunks were cut centrally to the point of stimulation, but was absent when the hypogastric nerves were transected. We feel that sympathetic stimulation modulates the parasympathetic innervation of the bladder.

Treatment of infants with neurogenic bladder dysfunction using anticholinergic drugs and intermittent catheterisation

The use of anticholinergic drugs in infants with neurogenic dysfunction has not been well documented. In this study, 35 neonates at risk of upper urinary tract damage from neurogenic dysfunction were treated from infancy with anticholinergics, in combination with clean intermittent catheterisation. None of the patients showed upper urinary tract deterioration with follow-up ranging from 6 to 72 months, although 2 required vesicostomy--1 due to difficulty with catheterisation and 1 due to possible anticholinergic side effects. Only 2 (6%) have had clinical pyelonephritis. Twenty-five (76%) are virtually dry between catheterisation. We conclude that anticholinergics are safe and effective, even in the neonatal period, when used in combination with clean intermittent catheterisation for the treatment of neonates with neurogenic bladder dysfunction.

The effect of venous incompetence and arterial insufficiency on erectile function: an animal model

We designed an animal model to elucidate the effect of venous leakage and arterial insufficiency on erectile function. In 10 dogs, electrodes were implanted around the cavernous nerves for electroerection and blood flow in the internal pudendal artery was recorded. Venous leakage was mimicked by inserting needles of varying gauges (30 to 16G) into the corpus cavernosum and the erectile response to neurostimulation was recorded before and after the creation of the leak. The relationship between the size and the amount of the venous leakage, the changes in the intracavernous pressure (peak and drop), and the changes in the peak and maintenance arterial blood flow were documented. Arterial blood flow was then reduced by 25 and 50 per cent by means of a screw clamp on the terminal aorta. The erectile response to neurostimulation was again determined, with the same electrical parameters, first with reduced blood flow alone, then in combination with leakage of varying size. Our results showed that minor cavernous vein leakage in the presence of normal arterial flow and a healthy sinusoidal system had a minimal effect on erectile function owing to a compensatory increase in penile blood flow. However, when reduction of arterial blood flow was superimposed on venous leakage, even of a minor degree, the erectile response to neurostimulation was markedly impaired.

A possible role for calcitonin-gene-related peptide in the regulation of the smooth muscle tone of the bladder and penis

We investigated the effect of calcitonin-gene-related peptide (CGRP) on bladder contractions and penile erection in 12 dogs. In a system in which the arteries were tied bilaterally to ensure delivery of high drug levels to the bladder, arterial injections of CGRP significantly reduced the peak intravesical pressure of bladder contractions induced by pelvic nerve stimulation or arterial injection of carbachol. When given intravenously, CGRP had no effect on bladder contractions consequent to neural stimulation. Intravesical instillation of CGRP, however, reduced the bladder contractions significantly. Histologic staining showed CGRP-immunoreactive nerve fibers within the smooth muscle layers of the bladder wall. Intracavernous CGRP increased cavernous arterial flow and induced cavernous smooth muscle relaxation and venous outflow occlusion. Muscarinic blockade had no effect on the canine intracavernous pressure response to intracavernous injection of CGRP. Histologic staining for CGRP-immunoreactivity showed nerve-fiber-like staining within the cavernous arterial wall, the nerves running near the cavernous arteries, and the cavernous smooth muscles. Our results suggest a possible role for CGRP in the regulation of the smooth muscle tone of the bladder and penis.

Local and systemic effects of chronic intracavernous injection of papaverine, prostaglandin E1, and saline in primates

To compare the local and systemic effects of chronic intracavernous injection of papaverine, prostaglandin E1, and saline on erectile tissue, eight pigtail monkeys underwent 75 injections over a nine-month period. Monkeys were divided into three groups; each group received papaverine (10 mg.), prostaglandin E1 (20 micrograms.), or saline (one ml.). The erectile response was closely observed for two hours after each injection to monitor the onset, degree, and duration of erection. Liver function tests were performed every three months to detect early systemic metabolic changes. After sacrifice, the simian penises were perfused in situ and examined histologically with both light and electron microscopy. Papaverine resulted in an initially strong erectile response, but this was maintained throughout the length of the study in only two monkeys. In contrast, prostaglandin E1 resulted in tumescence that was maintained in all monkeys over the nine-month period. In addition, the papaverine group had elevated liver enzymes and significant histologic changes with loss of normal architecture on both light and electron microscopy. The other two groups showed only minimal histologic changes or none.

Acetylcholine as a possible neurotransmitter in penile erection

We investigated the erectile response to intracavernous injection of increasing doses of acetylcholine (0.5 to 500 micrograms.) in 10 monkeys. To differentiate between nicotinic (ganglionic) and muscarinic (parasympathetic postganglionic) effects, acetylcholine was likewise administered after 1.6 mg. trimethaphan camsylate and 0.1 mg. atropine, alone or sequentially. Erections were induced by cavernous nerve stimulation before and after atropine. Acetylcholine induced a dose-dependent, triphasic erectile response: a first tumescence phase followed by contraction and a subsequent second phase of tumescence. Atropine reduced but did not abolish the erectile response to acetylcholine: attainment of maximal intracavernous pressure after neurostimulation was both delayed and reduced (mean 25 cm. H2O). Only after combined nicotinic and muscarinic blockade was the erectile response to acetylcholine completely abolished. Histologic staining for acetylcholinesterase in five additional monkeys that had not received acetylcholine showed dense staining within the cavernous erectile tissue and around the cavernous arteries. Our data suggest that acetylcholine is a possible neurotransmitter for penile erection in monkeys.

Possible role for acetylcholine as a neurotransmitter in canine penile erection

In 15 adult dogs, the possible role of acetylcholine as a parasympathetic neurotransmitter in canine penile erection was investigated. Intracavernous injection of increasing dosages of acetylcholine (0.1-100 micrograms) induced a dose-dependent erectile response with increased arterial flow, cavernous smooth muscle relaxation, and venous occlusion. This erectile response was completely abolished after muscarinic blockade by intracavernous injection of 0.1 mg atropine. After cavernous nerve stimulation, atropine injection significantly reduced the pudendal arterial flow (by 25%) and likewise caused a significant reduction in cavernous outflow restriction. Histologic staining showed acetylcholinesterase-positive fibers around the cavernous arteries and within the cavernous erectile tissue.

The rationale for pharmacologic cavernosography

To refine the diagnostic method for opacification of aberrant venous drainage in venogenic impotence, an experimental study was done in eight monkeys. In all monkeys, cavernosography after induction of erection by saline perfusion showed significant drainage via the cavernous veins. However, when cavernosography was performed after neurostimulation or papaverine injection, no cavernous drainage was visualized, even when the intracavernous pressure had been significantly lowered by creation of an artificial cavernous leak. Because erection can result from saline perfusion only when the volume perfused exceeds the venous outflow capability, cavernosography during saline-induced erection will always demonstrate the entire venous system and, thus, is of no diagnostic value. Pharmacocavernosography imitates the physiologic venous occlusive mechanism and should therefore be used to identify the abnormally draining veins in venogenic erectile dysfunction.

The diagnosis of venogenic impotence: dynamic or pharmacologic cavernosometry?

In an attempt to refine the diagnosis of venogenic impotence, we evaluated different techniques of cavernosometry in 10 dogs. Saline was perfused intracavernously in five dogs to induce erection. Regardless of the amount required for induction, a mean flow rate of 23.4 ml./min. was necessary to maintain an intracavernous pressure level of 110 cm. H2O. In seven dogs, a leak was created by intracavernous insertion of a 19-gauge needle. When erection was induced by either cavernous nerve stimulation or a combination of papaverine injection and saline perfusion, the mean flow through the needle was significantly less than when erection was induced by saline perfusion alone (1.73, 1.78, and 8.77 ml./min., respectively). Sympathetic trunk stimulation at the level of L5 could reduce the intracavernous pressure by 90% in erections induced by neural stimulation or papaverine plus perfusion but had no effect on erection induced by saline perfusion alone. Our findings show that cavernosometry after intracavernous injection of papaverine will provide more valuable information in patients in whom venogenic impotence is suspected.

[Inguinal hernia. The Shouldice parietal repair]

Parietal repair according to the Shouldice technique consists of a double line of sutures on each of three musculo-aponeurotic layers of the groin, i.e. successively: plicature of the transverse muscle and attachments; aponeuroplasty by back-to-back suture of the internal and external oblique muscles, and plicature of the aponeurosis of the external oblique muscle. Parietal repair of this kind is only possible after wide dissection of the inguinal region. It can be performed under local anaesthesia during a short hospitalization period. Normal activity is rapidly resumed, and in the experience of those who favour this technique, the recurrence rate is a mere 1%.