Local thermal stimulation relaxes hypertonic anal sphincter: evidence of somatoanal reflex

What every PA needs to know about anorectal pain

Anorectal pain is common but often misdiagnosed, and patients may suffer in silence if they are too uncomfortable discussing the topic with their healthcare provider. This article reviews rectal anatomy and the signs and symptoms of several common anorectal conditions and how to manage them.

Moxibustion Alleviates Injury in a Rat Focal Segmental Glomerulosclerosis Model

Objectives

To evaluate the therapeutic effects of moxibustion at Shenshu (BL-23) and Geshu (BL-17) acupoints in a focal segmental glomerulosclerosis (FSGS) model in rats.

Methods

A FSGS rat model was established by single nephrectomy and repeated injection of doxorubicin. The FSGS rats were randomly divided into the model group, losartan (positive control) group, Shenshu moxibustion group, and Geshu moxibustion group. Molecular indicators of kidney function and renal pathological changes were monitored.

Results

Urinary protein, serum creatinine, urea nitrogen, and serum uric acid were significantly reduced after 12-week intervention with losartan, Shenshu, or Geshu moxibustion. Renal α-SMA, FN, and TGF-β were also decreased, while podocin and nephrin protein and mRNA were increased. The pathological damage in renal tissue was obviously alleviated by all three treatments, which suggests that moxibustion may have similar efficacy to losartan in the treatment of FSGS.

Conclusion

Moxibustion alleviates podocyte injury and inhibits renal interstitial fibrosis in the FSGS rat model, thereby minimizing the progression of glomerular sclerosis and improving renal function.

Myoxinol ointment for the treatment of acute fissure

Myoxinol is a complex of oligopeptides obtained from the seeds of Hibiscus esculentus used in cosmetic as natural alternative to botulin toxin. The aim of the study was to evaluate the safety and effectiveness of local myoxinol for the treatment of acute anal fissure. All the consecutive patients with acute fissure treated from January to June 2014 underwent 30 days of topical treatment (twice/day) with a mioxinol based ointment. Pain, symptomatic relief, fissure healing and re-epithelization, 1-year recurrence rate, subjective satisfaction and need for further treatments were evaluated. During the study period 157 patients were eligible for data analysis (91 males: 58%; mean age 38 years: range 17-83). Median anal pain score was 7.1 pre-treatment and 1.7 and 0.9 after 30 days and 12 months from treatment, respectively (p: 0.0001). After the treatment period complete healing was achieved in 103 patients (65.5%), relevant improvement in 31 (20%) and no improvement in 21 patients (13.5%). Overall efficacy rate was 85.5%. A significant difference was reported considering patients with pre-treatment VAS between 1-5 and 6-10 (p: 0.004). Twenty-nine patients (18.5%) required further treatments. Hydrolyzed Hibiscus esculentus extract was proven to be an effective and well-tolerated topical treatment for acute fissure, with a high healing rate, a significant reduction of pain and a low 1-year recurrence rate.

Anal fissure

An anal fissure is a common, mostly benign, condition that can be acute or chronic. The diagnosis is usually made on history and physical examination, but further investigations are sometimes necessary. Primary fissures are usually benign and located in the posterior or anterior position. Secondary fissures are lateral or multiple and often indicate a more serious underlying pathology. The management of primary anal fissures is generally non-operative and includes increased dietary fibre, sitz baths, topical ointments and botulinum toxin injections. If these treatments are ineffective the patient will need a surgical referral. Secondary anal fissures require further investigation. Multidisciplinary management is preferable and is essential in the case of malignancy.

Comparison between a new electronic bidet and conventional sitz baths: a manometric evaluation of the anal resting pressure in normal healthy volunteers

BACKGROUND

A bidet has been proposed as a replacement for the sitz bath. Like a sitz bath, it brings water into contact with the perineum. However, the high force of water from commercially used electronic bidets may harm the anus. We developed a new electronic bidet and evaluated its effects on anal resting pressure compared with a warm sitz bath.

METHODS

Forty volunteers used the electronic bidet and sitz bath on separate days. The electronic bidet was newly designed with warm (38 °C) water and very low force (10 mN) with a fountain type of flow. Anal resting pressure at the high-pressure zone was measured before (control) and after the electronic bidet and sitz bath. Pressure changes after bidet or sitz bath were expressed as percentages compared with control. Water temperatures and rectal temperatures were also recorded.

RESULTS

The anal resting pressures before the electronic bidet and sitz bath were 90.2 ± 24.6 and 88.1 ± 16.8 mmHg, respectively. At 3 min after the electronic bidet and sitz bath, the anal resting pressures were 71.3 ± 23.4 and 69.6 ± 19.8 mmHg, respectively. The pressure changes compared with the control were 78.2 ± 12.9 and 78.1 ± 12.5%, respectively, which were not significantly different. The maximal increase and minimal decrease were not significantly different. The rectal temperature was not elevated, and the water temperature decreased significantly with the sitz bath (p < 0.001).

CONCLUSIONS

Our new electronic bidet may reduce the anal resting pressure much like a warm sitz bath does.

Effects of Different Local Moxibustion-Like Stimuli at Zusanli (ST36) and Zhongwan (CV12) on Gastric Motility and Its Underlying Receptor Mechanism

The aim of this study was to explore the "intensity-response" relationship in local moxibustion-like stimuli- (LMS-) modulated gastric motility and its underlying receptor mechanism. Based on the thermal pain threshold (43°C), 41°C, 43°C, and 45°C LMS were separately applied to ST36 or CV12 for 180 s among ASIC3 knockout (ASIC3-/-) mice, TRPV1 knockout (TRPV1-/-) mice, and their homologous wild-type C57BL/6 mice (n = 8 in each group). Gastric motility was continuously measured by an intrapyloric balloon, and the amplitude, integral, and frequency of gastric motility during LMS were compared with those of initial activities. We found that both 43°C and 45°C LMS at ST36 induced significantly facilitated effect of gastric motility (P < 0.05), while LMS at CV12 induced inhibited effects (P < 0.05). 41°C LMS had no significant impact on gastric motility. Compared with C57BL/6 mice, the facilitatory effect at ST36 and inhibitive effect of LMS at CV12 were decreased significantly in TRPV1-/- mice (P < 0.05; P < 0.01) but not changed markedly in ASIC3-/- mice (P > 0.05). These results suggest that there existed an "intensity-response" relationship between temperature in LMS and its effects on gastric motility. TRPV1 receptor played a crucial role in the LMS-modulated gastric motility.

The Effect of Early Warm Plastic Bag Application on Postoperative Pain after Hemorrhoidectomy: A Prospective Randomized Controlled Trial

Hemorrhoidectomy is used for the surgical treatment of high-grade hemorrhoids. The most prominent complaint after hemorrhoidectomy is pain. Postoperative pain management is still a big problem after surgery in patients with hemorrhoidectomy. The aim of the study was to assess the effect of early application of warm bag on postoperative pain after hemorrhoidectomy. All patients were randomly divided into warm plastic bag and control groups by using sealed envelopes, which were prepared preoperatively. After standard spinal anesthesia, all patients underwent standard Milligan-Morgan hemorrhoidectomy using Ligasure™. Although the study group received the warm bag application, the control group did not receive such a treatment. Two separate visual analog scale (VAS) measurements were performed for postoperative pain assessments on postoperative days, one during the resting state and the other one during the straining phase after the onset of peristaltic bowel movement. Postoperative VAS scores were significantly lower among the warm plastic bag group as compared with the control group on Days 1 and 3 for the resting state and on Day 3 for defecation. Additionally, a significant difference existed between the two groups in terms of the need for additional anesthesia. Local thermal application appears to be a safe and effective method for pain relief after hemorrhoidectomy.

Somatosensory Nerve Fibers Mediated Generation of De-qi in Manual Acupuncture and Local Moxibustion-Like Stimuli-Modulated Gastric Motility in Rats

The aim of this study was to reveal the somatosensory nerve fibers mediated generation of De-qi in manual acupuncture stimuli (MAS) and local moxibustion-like stimuli (LMS). The effects of strong and slight MAS, as well as 41°C, 43°C, and 45°C LMS at ST36 and CV12 on gastric motility were observed in rats. Gastric motility was continuously measured by an intrapyloric balloon, and the average amplitude, integral, and frequency of gastric motility during LMS were compared with those of background activity. Gastric motility was facilitated by MAS and LMS at ST36 and inhibited at CV12. The modulatory effects induced by strong MA with potent De-qi (needle grasp feeling) were markedly higher than those by slight MA with mild De-qi sensation (P < 0.05). The nociceptive 43°C and 45°C LMS, rather than nonnociceptive 41°C LMS, produced significant regulatory effects on gastric motility. Based on the afferent fibers activated in the present study, these results support the hypothesis that A δ - and C-afferent fibers were more likely to be involved in the generation of De-qi sensation.

How does moxibustion possibly work?

“Acupmoxa” is a hybrid word of “acupuncture” and “moxibustion” that more closely resembles the Chinese ideograph for this treatment. People in Western countries are more familiar with acupuncture, while moxibustion is less popular, partially due to the paucity of scientific studies. Although the evidence-based efficacy of moxibustion needs to be further clarified, the mechanisms by which moxibustion may work include temperature-related and nontemperature-related ones. Local somatothermal stimulation (LSTS), one type of moxibustion, is achieved by application of a heat source to and above the acupoint. Such mild heat stimulation of the acupoint induces little skin damage, in contrast to the burning effect of moxibustion, but does provoke mild oxidative stress in the viscera. Thus, preconditioned LSTS at the peripheral acupoints LR 14 and PC 6 of animals is able to induce visceral HSP70 expression and to protect the liver and the heart against ischemia-reperfusion injury. Nontemperature-related mechanisms include smoke, herbs, and biophysical (far infrared) stimulation. We conclude that LSTS, a remote preconditioning method, has potential clinical usefulness. However, evidence-based efficacy and safety studies involving large-scaled clinical trials are needed in order that this approach will pass muster with Western scientists.

Anal fissure

Anal fissure is one of the most common anorectal problems. Anal fissure is largely associated with high anal sphincter pressures and most treatment options are based on reducing anal pressures. Conservative management, using increased fiber and warm baths, results in healing of approximately half of all anal fissures. In fissures that fail conservative care, various pharmacologic and surgical options offer satisfactory cure rates. Lateral internal sphincterotomy remains the gold standard for definitive management of anal fissure. This review outlines the key points in the presentation, pathophysiology, and management of anal fissure.

The management of patients with primary chronic anal fissure: a position paper

Anal fissure is one of the most common and painful proctologic diseases. Its treatment has long been discussed and several different therapeutic options have been proposed. In the last decades, the understanding of its pathophysiology has led to a progressive reduction of invasive and potentially invalidating treatments in favor of conservative treatment based on anal sphincter muscle relaxation. Despite some systematic reviews and an American position statement, there is ongoing debate about the best treatment for anal fissure. This review is aimed at identifying the best treatment option drawing on evidence-based medicine and on the expert advice of 6 colorectal surgeons with extensive experience in this field in order to produce an Italian position statement for anal fissures. While there is little chance of a cure with conservative behavioral therapy, medical treatment with calcium channel blockers, diltiazem and nifepidine or glyceryl trinitrate, had a considerable success rate ranging from 50 to 90%. Use of 0.4% glyceryl trinitrate in standardized fashion seems to have the best results despite a higher percentage of headache, while the use of botulinum toxin had inconsistent results. Nonresponding patients should undergo lateral internal sphincterotomy. The risk of incontinence after this procedure seems to have been overemphasized in the past. Only a carefully selected group of patients, without anal hypertonia, could benefit from anoplasty.

What every gastroenterologist needs to know about common anorectal disorders

Anorectal complaints are very common and are caused by a variety of mostly benign anorectal disorders. Many anorectal conditions may be successfully treated by primary care physicians in the outpatient setting, but patients tend not to seek medical attention due to embarrassment or fear of cancer. As a result, patients frequently present with advanced disease after experiencing significant decreases in quality of life. A number of patients with anorectal complaints are referred to gastroenterologists. However, gastroenterologists’ knowledge and experience in approaching these conditions may not be sufficient. This article can serve as a guide to gastroenterologists to recognize, evaluate, and manage medically or non-surgically common benign anorectal disorders, and to identify when surgical referrals are most prudent. A review of the current literature is performed to evaluate comprehensive clinical pearls and management guidelines for each topic. Topics reviewed include hemorrhoids, anal fissures, anorectal fistulas and abscesses, and pruritus ani.

Effects of Warm Water Sitz Bath on Symptoms in Post-anal Sphincterotomy in Chronic Anal Fissure—A Randomized and Controlled Study

BACKGROUND

Sitz bath is frequently recommended by physicians for a variety of anal disorders including anal fissure. The aim of the present study was to determine whether sitz bath does have any therapeutic properties improving upon a patient's postoperative symptoms after a closed lateral sphincterotomy.

MATERIALS AND METHODS

Forty-six patients were randomly assigned to receive analgesics and fiber supplement alone (control patients) or a twice-daily sitz bath along with identical fiber and analgesics (sitz bath group). A 24-h pain score--post-defecation anal burning and symptom improvement--was evaluated on a visual analog scale (VAS).

RESULTS

The groups were equally matched for age, gender distribution, and duration of disease. No significant difference in mean pain score between groups (p = 0.284) was noticed after one week. However, the patients from the control group experienced significant anal burning compared with patients from sitz bath group (p < 0.0001). The improvement score was higher in the sitz bath group when compared with the control group; however, it did not reached a statistically significant level.

CONCLUSIONS

Patients after sphincterotomy for anal fissure receiving sitz bath experienced similar levels of pain when compared with those not receiving sitz bath. However, they reported a significant relief in anal burning and a marginally better satisfaction score and no reported adverse side effects.

Preconditioned somatothermal stimulation on median nerve territory increases myocardial heat shock protein 70 and protects rat hearts against ischemia-reperfusion injury

OBJECTIVE

This study was designed to test the hypotheses that local somatothermal stimulation on the left median nerve territory increases myocardial heat shock protein 70 and that preconditioning of rats with local somatothermal stimulation protects the hearts against subsequent ischemia-reperfusion injury.

METHODS

Local somatothermal stimulation was brought about by means of application of a heating rod over and above the left median nerve territory (1.5 cm proximal to the palm crease) in male Sprague-Dawley rats. After rats were treated with local somatothermal stimulation, the gene expression of heat shock protein 70 in regional muscle, heart, and liver was assessed by means of Western blotting and reverse transcription-polymerase chain reaction. In addition, durations of arrhythmia, mortality rates, and mitochondrial functions were compared between groups preconditioned with or without local somatothermal stimulation followed by subsequent myocardial ischemia-reperfusion injury.

RESULTS

The results showed that the gene expression of heat shock protein 70 was upregulated in the muscle beneath the area of local somatothermal stimulation, as well as in the heart, although not in the liver. When animals were preconditioned with local somatothermal stimulation on the left median nerve territory followed by subsequent ischemia-reperfusion injury of the heart, there were significant decreases of creatine kinase level from the heart, duration of arrhythmia, mortality rate, and improved mitochondrial respiratory function compared with that seen in those without local somatothermal stimulation preconditioning.

CONCLUSION

We conclude that local heat stress preconditioning on the left median nerve territory has a potential cardioprotective effect against subsequent ischemia-reperfusion injury.

Local somatothermal stimulation inhibits motility of the internal anal sphincter through nitrergic neural release of nitric oxide

PURPOSE

A somatoanal reflex had been demonstrated in our previous work. Because nitric oxide plays an important role in mediating relaxation of the internal anal sphincter, our purpose was to examine whether and how local somatothermal stimulation inhibits the function of the internal anal sphincter by stimulating nitric oxide release via nitrergic neurons and to elucidate the possible mechanism.

METHODS

The activity of the internal anal sphincter in anesthetized rabbits was measured by use of continuously perfused, open-tip manometric methods. Local somatothermal stimulation was achieved by applying an electroheating rod 1 cm away from the skin area at the right popliteal region. The responses were further manipulated by pre-treating the rabbits with agonists or antagonists linked to nitric oxide synthesis.

RESULTS

The motility of the internal anal sphincter before and during local somatothermal stimulation was significantly different (tonic pressure (mean +/-standard error of the mean), 5.4 +/- 0.3 vs. 4.9 +/- 0.3 mmHg, P = 0.0195; phasic pressure, 3.9 +/- 0.6 vs. 2.9 +/- 0.4 mmHg, P = 0.0002; frequency distribution of the phasic contractions (peak-to-peak interval), 28.9 +/- 3.7 vs. 65.3 +/- 10.4 seconds, P = 0.0001). The response began at approximately one minute after local somatothermal stimulation when the skin temperature was 41 +/- 0.3 degrees C. No anal response was observed when local somatothermal stimulation was applied at the control area. The local somatothermal stimulation-induced internal anal sphincter relaxation was not inhibited by pretreatment with atropine, propranolol, or phentolamine (tonic pressure, 5.8 +/- 1 vs. 5.2 +/- 0.8 mmHg, P = 0.038; phasic pressure, 4.2 +/- 0.9 vs. 3.1 +/- 0.6 mmHg, P = 0.020; peak-to-peak interval, 27.2 +/- 4.3 vs. 52.9 +/- 14.5 seconds, P = 0.043) but was completely blocked by pretreatment with a nitric oxide synthesis inhibitor. The effect of the nitric oxide synthesis inhibitor could be reversed by pretreatment with L-arginine (tonic pressure, 6 +/- 0.7 vs. 5.6 +/- 0.7 mmHg, P = 0.047; phasic pressure, 4.7 +/- 0.7 vs. 3.9 +/- 0.5 mmHg, P = 0.048; peak-to-peak interval, 23.8 +/- 3 vs. 33 +/- 3.7 seconds, P = 0.048), but not by D-arginine.

CONCLUSION

Local somatothermal stimulation inhibits internal anal sphincter motility through the activation of nonadrenergic noncholinergic neural release of nitric oxide. This procedure may represent a simplified approach for the treatment of anorectal diseases with hypofunction of the L-arginine/nitric oxide pathway. [Key words: Local somatothermal stimulation; Nitric oxide; Internal anal sphincter; Motility; Moxibustion] Jiang J-K, Chiu J-H, Lin J-K. Local somatothermal stimulation inhibits motility of the internal anal sphincter through nitrergic neural release of nitric oxide.