sphincter muscle [keywords]
- Submucosal Elastic Laminae of the Middle and Lower Pharynx: A Histological Study Using Elderly Cadaveric Specimens. [JOURNAL ARTICLE]
- Dysphagia 2016 Jul 19.
Although the pharyngeal wall is well known to have high elasticity, the distribution of submucosal elastic fibers has not been described. Observations of histological sections of the mid and lower pharyngeal walls from 15 elderly donated cadavers were made. We found two distinct submucosal tissue layers with a high content of elastic fibers (tentatively termed the "submucosal elastic laminae"). The inferolateral elastic lamina was restricted to the level from the upper part of the arytenoid to the lower end of the inferior cornu of the thyroid cartilage. It originated from the pharyngeal submucosa, extended laterally along the inner aspect of the thyropharyngeal muscle, and inserted into the posterior margin of the thyroid cartilage including the cornu. The posteromedial lamina extended along the supero-inferior axis from a level above the greater horn of the hyoid bone to reach the muscularis mucosae of the cervical esophagus. The inferolateral and posteromedial laminae were connected at levels below the cricoarytenoid joint. Individual variations were evident in their thicknesses (ranging from almost absent to 0.3 mm) as well as the extent of connection between them. In association with striated muscle function, the inferolateral lamina seemed to suspend the lower pharyngeal mucosa, while the posteromedial lamina seemed to provide mucosal fold forcing smoothly peristaltic conveyance of a bolus during swallowing.
- Managing Esophageal Dysphagia in the Elderly. [REVIEW, JOURNAL ARTICLE]
- Curr Treat Options Gastroenterol 2016 Jul 16.
Esophageal dysphagia in the elderly is a common clinical problem. Achalasia is a disease in which there is loss of ganglion in the myenteric plexus of the lower esophageal sphincter resulting in incomplete relaxation of that muscle causing a functional obstruction to outflow. Treatment is aimed at reducing sphincter pressure allowing for gravity and the oral portion of the swallow to propel the bolus through the esophagus. Pneumatic dilatation, Heller myotomy (laparoscopic), and the newest procedure peroral endoscopic esophageal myotomy (POEM) are all reasonable options for effective treatment even in the elderly. The choice depends on the decision of the patient, subtype of achalasia, local expertise, and fitness for surgery. Patients over 45 with type 2 achalasia respond exceptionally well to pneumatic dilation, and we recommend consideration of this technique if expertise is available. POEM has achieved excellent short-term results and if local expertise exists, it should be strongly considered especially in patients with type 3 achalasia. Type 1 achalasia may respond slightly better to myotomy, either Heller or POEM. Proton pump inhibitors remain the treatment of choice for GERD and should not be avoided in the elderly for fear of adverse reactions. While none of the FDA warnings nor concern for chronic renal failure or dementia can be dismissed, much more research is needed before we accept that PPIs are truly causal. Surgery for GERD in patients over 65 is as effective as in the young and should be considered in appropriate candidates. Eosinophilic esophagitis, while not common in the elderly, frequently results in clinically important dysphagia. PPIs, topical oral steroids, and dietary interventions are all used individually and together to improve symptoms. PPIs remain first line and are required twice daily for at least 8 weeks as an initial trial. Dilation with either balloons or polyvinyl dilators are highly effective in patients with rings and focal strictures, can be performed safely, and limit the number of medications an elderly patient needs to take.
- Anatomical and functional deficiencies of the crural diaphragm in patients with esophagitis. [JOURNAL ARTICLE]
- Neurogastroenterol Motil 2016 Jul 14.
Inspiratory esophagogastric junction (EGJ) pressure is lower in gastroesophageal reflux disease (GERD) and patients fail to increase EGJ pressure during the inspiratory effort. The aim of this study was to assess the EGJ activity during inspiratory maneuvers (high-resolution manometry, HRM) and the crural diaphragm (CD) thickness (endoscopic ultrasound, EUS) in GERD.Twenty esophagitis patients (average age 45 years, 7 grade A, 13 grade B) had HRM and EUS. Forty-three controls were recruited; 30 had HRM (average age 33 years), and 13 had EUS (average age 40 years). The EGJ contractility index (EGJ-CI) (mm Hg×cm) was measured during normal respiration and two inspiratory maneuvers: without and with inspiratory loads of 12, 24, and 48 cmH2 O (TH-maneuvers). A composite metric for TH-maneuvers ("EGJ total activity") was defined as the product of the maximal EGJ pressure and the length of its aboral excursion during the maneuver (mm Hg×cm). The CD thickness (cm) was measured during expiration (12 MHz).Expiratory lower esophageal sphincter pressure and integrated relaxation pressure were lower in GERD. The EGJ-CI and the "EGJ total activity" were lower in GERD during TH-maneuvers (48-cmH2 O load: 168.4 ± 13.8 vs 114.8 ± 9.6, P=.006). Patients failed to sustain the inspiratory CD activity across the 12 and 48-cmH2 O efforts. The CD was thinner in GERD patients (0.37 ± 0.03 vs 0.49 ± 0.04, P=.02). The CD thickness correlated with the increment in the "EGJ total activity" in GERD without a hiatal hernia (r=.702, P=.016, n=11).There are anatomical changes and functional failure of the CD in esophagitis patients supporting the possibility of a skeletal muscle deficiency in GERD.
- Levator ani defects in patients with stress urinary incontinence: three-dimensional endovaginal ultrasound assessment. [JOURNAL ARTICLE]
- Int Urogynecol J 2016 Jul 8.
To determine the prevalence of levator ani (LA) muscle subdivision defects in patients with SUI using three-dimensional endovaginal ultrasound (3D EVUS).This is a prospective cohort study of 100 patients with pure or predominant urodynamic SUI who underwent 3D EVUS. The 3D cubes obtained were analyzed and the LA muscle was divided into three subgroups: the puboperinealis/puboanalis, the puborectalis, and the iliococcygeus/pubococcygeus. Each LA muscle subdivision was individually scored on each side (0: no defect, 1: ≤50 % muscle loss, 2: > 50 % muscle loss, and 3: total absence of the muscle) and a cumulative score, categorized as 0 (no defect), mild (total score 1-6), moderate (7-12), and severe (≥13) was calculated.The number of women with no LA muscle defect or a mild defect was significantly higher than the number of those with a moderate or severe defect (p < 0.001). Apart from the small inverse relationship of the total puborectalis muscle score and the cumulative subdivision score with maximal urethral closure pressure (r value > -0.3; p < 0.05), the muscle defect scores were not found to correlate with urodynamic parameters (p > 0.05). Although all muscle subdivisions contributed to the overall LA muscle defect score, the association was strongest for the puborectalis component (r = 0.9; p < 0.001). The prevalence of the LA muscle defect in patients with intrinsic sphincter deficiency (ISD) was not significantly different from that in patients without ISD.Patients with SUI have a higher prevalence of no or mild LA defect compared with a moderate or severe LA defect.
- Perineal raphe with special reference to its extension to the anus: a histological study using human fetuses. [Journal Article]
- Anat Cell Biol 2016 Jun; 49(2):116-24.
The raphe of the human penis and scrotum is considered to develop secondarily after disappearance of the initial midline seam by fusion of the bilateral genital folds. However, the fetal development was still obscure. We examined histological sections of 30 fetuses (17 males and 13 females) at 10-15 weeks. In male fetuses, the scrotum was not yet clearly identified because of no descent of testis. The perineal raphe was thin and wavy at 10 weeks, and it was continuous with and took a direction same as the inferior wall of the closed penile urethra after physiological hypospadias. Depending on growth of the bulbospongiosus muscle and corpus spongiosus penis, the midline intermuscular septum obtained a connection to the subcutaneous wavy raphe and made the latter thick and straight at 12-15 weeks. Notably, the perineal raphe extended posteriorly to attach to the external anal sphincter. In female fetuses, an epithelial fusion occurred along a short distance at the posterior end of the vestibule. However, in front of the external anal sphincter, a large midline mesenchymal tissue from the urorectal septum did not contain a raphe-like structure. Moreover, since the bilateral bulbospongiosus muscles were separated widely by the vestibule, they did not provide a midline septum. Fetal development of the perineal raphe was accelerated by reinforcement from the muscular septum. In contrast, without such a muscular support, the female raphe could not maintain its growth even if the seed appeared at the posterior end of the vestibule.
- Neuromodulation of the neural circuits controlling the lower urinary tract. [JOURNAL ARTICLE]
- Exp Neurol 2016 Jul 2.
The inability to control timely bladder emptying is one of the most serious challenges among the many functional deficits that occur after a spinal cord injury. We previously demonstrated that electrodes placed epidurally on the dorsum of the spinal cord can be used in animals and humans to recover postural and locomotor function after complete paralysis and can be used to enable voiding in spinal rats. In the present study, we examined the neuromodulation of lower urinary tract function associated with acute epidural spinal cord stimulation, locomotion, and peripheral nerve stimulation in adult rats. Herein we demonstrate that electrically evoked potentials in the hindlimb muscles and external urethral sphincter are modulated uniquely when the rat is stepping bipedally and not voiding, immediately pre-voiding, or when voiding. We also show that spinal cord stimulation can effectively neuromodulate the lower urinary tract via frequency-dependent stimulation patterns and that neural peripheral nerve stimulation can activate the external urethral sphincter both directly and via relays in the spinal cord. The data demonstrate that the sensorimotor networks controlling bladder and locomotion are highly integrated neurophysiologically and behaviorally and demonstrate how these two functions are modulated by sensory input from the tibial and pudental nerves. A more detailed understanding of the high level of interaction between these networks could lead to the integration of multiple neurophysiological strategies to improve bladder function. These data suggest that the development of strategies to improve bladder function should simultaneously engage these highly integrated networks in an activity-dependent manner.
- Galectin-1-induced skeletal muscle cell differentiation of mesenchymal stem cells seeded on an acellular dermal matrix improves injured anal sphincter. [Journal Article]
- Discov Med 2016 May; 21(117):331-40.
According to recent studies, mesenchymal stromal cells (MSCs) transplanted via local or tail vein injection can improve healing after anal sphincter injury (ASI) in animal models. However, the transplanted MSCs do not generate skeletal muscle that completely resembles the natural anal sphincter structure. In the present study, we investigated whether bone marrow (BM)-derived MSCs could be induced by Galectin-1 (Gal-1) to differentiate into skeletal muscle and whether the recellularization of an acellular dermal matrix (ADM) with skeletal muscle-differentiated MSCs represents a promising approach to restore ASI in a rat model. BM-MSCs subjected to adenovirus-mediated transfection with Gal-1-GFP (Ad-GFP-Gal-1) displayed increased Gal-1 and desmin expression and differentiated into skeletal muscle cells. MSCs transfected with Ad-GFP-Gal-1 (MSC-Gal-1) were seeded onto an ADM (ADM-MSC-Gal-1) via co-culture, and fusion was observed using a confocal laser scanning microscope. ADM-MSC-Gal-1, ADM-MSC, ADM-MSC-Ad, ADM, or a saline control was applied to a rat ASI model, and injury healing was evaluated via histological examination 6 weeks following treatment. ADM-MSC-Gal-1 treatment promoted significant healing after ASI and improved external anal sphincter contraction curves compared with the other treatments and also led to substantial skeletal muscle regeneration and neovascularization. Our results indicate that repair using ADMs and differentiated MSCs may improve muscle regeneration and restore ASI.
- The immediate effect of vaginal and caesarean delivery on anal sphincter measurements. [Journal Article]
- J Int Med Res 2016 Aug; 44(4):824-31.
This study evaluated the effects of vaginal and caesarean delivery on internal and external anal sphincter muscle thickness using translabial ultrasonography (TL-US).This prospective cohort study enrolled nulliparous women who either had vaginal or caesarean deliveries. The thickness of the hypoechoic internal anal sphincter (IAS) and hyperechoic external anal sphincter (EAS) at the 12, 3, 6, and 9 o'clock positions at the distal level were measured before delivery and within 24-48 h after delivery.A total 105 consecutive women were enrolled in the study: 60 in the vaginal delivery group and 45 in the caesarean delivery group. The IAS muscle thickness at the 12 o'clock position in the vaginal delivery group was significantly thicker before compared with after delivery (mean ± SD: 2.31 ± 0.74 mm versus 1.81 ± 0.64 mm, respectively). The EAS muscle thickness at the 12 o'clock position in the vaginal delivery group was significantly thicker before compared with after delivery (mean ± SD: 2.42 ± 0.64 mm versus 1.97 ± 0.85, respectively).There was significant muscle thinning of both the IAS and EAS at the 12 o'clock position after vaginal delivery, but not after caesarean delivery.
- [Prevention of intraoperative incidental injuries during sphincter-preserving surgery for rectal cancer and management of postoperative complication]. [English Abstract, Journal Article]
- Zhonghua Wei Chang Wai Ke Za Zhi 2016 Jun 25; 19(6):624-9.
Prevention of intraoperative incidental injuries during radical operation for rectal cancer and management of postoperative complication are associated with successful operation and prognosis of patients. This paper discusses how to prevent such intraoperative incidental injuries and how to manage postoperative complication. (1) Accurate clinical evaluation should be performed before operation and reasonable treatment decision should be made, including determination of the distance from transection to lower margin of the tumor, T and M staging evaluated by MRI, fascia invasion of mesorectum, metastasis of lateral lymph nodes, metastatic station of mesentery lymph node, association between levator ani muscle and anal sphincter, course and length of sigmoid observed by Barium enema, length assessment of pull-through bowel. Meanwhile individual factors of patients and tumors must be realized accurately. (2) Injury of pelvic visceral fascia should be avoided during operation. Negative low and circumference cutting edge must be ensured. Blood supply and adequate length of pull-down bowel must be also ensured. Urinary system injury, pelvic bleeding and intestinal damage should be avoided. Team cooperation and anesthesia procedure should be emphasized. Capacity of handling accident events should be cultivated for the team. (3) intraoperative incidental injuries during operation by instruments should be avoided, such as poor clarity of camera due to spray and smog, ineffective instruments resulted from repeated usage. (4) As to the prevention and management of postoperative complication of rectal cancer operation, prophylactic stoma should be regularly performed for rectal cancer patients undergoing anterior resection, while drainage tube placement does not decrease the morbidities of anastomosis and other complications. After sphincter-preserving surgery for rectal cancer, attentions must be paid to the occurrence of anastomotic bleeding, pelvic bleeding, anastomotic fistula, ileus, intestinal necrosis and anastomotic stenosis. After sphincter-preserving surgery for rectal cancer, if small amount of bleeding happens, titanium clamp or electric coagulation can be used; if delayed pelvic bleeding occurs obviously, embolism should be applied. Conservative treatment may be used for the non-carcinomatous ileus. When small anastomotic stenosis is found, local treatment is available (finger dilation, balloon expansion, transanal radiated cutting or resection), and for severe stenosis, transadominal operation is required.
- Effects of sphincter of Oddi motility on the formation of cholesterol gallstones. [Journal Article]
- World J Gastroenterol 2016 Jun 28; 22(24):5540-7.
To investigate the mechanisms and effects of sphincter of Oddi (SO) motility on cholesterol gallbladder stone formation in guinea pigs.Thirty-four adult male Hartley guinea pigs were divided randomly into two groups, the control group (n = 10) and the cholesterol gallstone group (n = 24), which was sequentially divided into four subgroups with six guinea pigs each according to time of sacrifice. The guinea pigs in the cholesterol gallstone group were fed a cholesterol lithogenic diet and sacrificed after 3, 6, 9, and 12 wk. SO manometry and recording of myoelectric activity were obtained by a multifunctional physiograph at each stage. Cholecystokinin-A receptor (CCKAR) expression levels in SO smooth muscle were detected by quantitative real-time PCR (qRT-PCR) and serum vasoactive intestinal peptide (VIP), gastrin, and cholecystokinin octapeptide (CCK-8) were detected by enzyme-linked immunosorbent assay at each stage in the process of cholesterol gallstone formation.The gallstone formation rate was 0%, 0%, 16.7%, and 83.3% in the 3, 6, 9, and 12 wk groups, respectively. The frequency of myoelectric activity in the 9 wk group, the amplitude of myoelectric activity in the 9 and 12 wk groups, and the amplitude and the frequency of SO in the 9 wk group were all significantly decreased compared to the control group. The SO basal pressure and common bile duct pressure increased markedly in the 12 wk group, and the CCKAR expression levels increased in the 6 and 12 wk groups compared to the control group. Serum VIP was elevated significantly in the 9 and 12 wk groups and gastrin decreased significantly in the 3 and 9 wk groups. There was no difference in serum CCK-8 between the groups.A cholesterol gallstone-causing diet can induce SO dysfunction. The increasing tension of the SO along with its decreasing activity may play an important role in cholesterol gallstone formation. Expression changes of CCKAR in SO smooth muscle and serum VIP and CCK-8 may be important causes of SO dysfunction.