Masahiro Takano

Management of early invasive colorectal cancer

PURPOSE: The purpose of this study was the evaluation of various factors in the formulation of guidelines for treatment of early invasive colorectal cancer, in which malignant cells extend through the muscularis mucosa into the submucosa but do not deeply invade the muscularis propria. METHOD: A total of 182 patients were followed for at least five years or until death, with early invasive cancer diagnosed between 1982 and 1989. Patients were grouped according to the level of invasion, as follows: 64 patients with slight carcinoma invasion of the muscularis mucosa (200–300 (μm;sm1), 82 with intermediate invasion (sm2), and 36 with carcinoma invasion extending to the inner surface of the muscularis propria (sm3). RESULT: The configuration, diameter, and histologic grade of adenocarcinoma and lymphovascular invasion were correlated with level of invasion. After endoscopic polypectomy or local resection, 4 patients showed local recurrence and 13 patients showed lymph node metastasis. None of these 17 patients had sml disease. The level of invasion, configuration, and location were significant risk factors for development of lymph node metastasis or local recurrence (P<0.05), but lymphovascular invasion, histologic grade, and diameter were not risk factors. CONCLUSIONS: Preoperative assessment of the level of invasion using this classification, in which the submucosa is divided into three depths, may decrease the incidence of unnecessary surgery for sessile polyps. Assessment according to the level of invasion is useful in the formulation of appropriate guidelines for the treatment of early invasive cancer.

Long-term results of intersphincteric resection for low rectal cancer.

PURPOSE: Intersphincteric resection has been performed as an alternative to abdominoperineal resection for low rectal cancer. The purpose of this study was to assess the long-term results after intersphincteric resection in terms of the morbidity, oncologic safety, and defecatory function. METHODS: Between 1994 and 2006, 107 consecutive patients with low rectal cancer had curative intersphincteric resection, categorized as total, subtotal, or partial resection of the internal anal sphincter. RESULTS: There were no mortalities. Neorectal mucosal prolapse in patients with total intersphincteric resection and coloanal anastomotic stenosis in patients with subtotal or partial intersphincteric resection were observed as characteristic late complications. The five-year disease-free survival rates classified according to the TNM stage were 100 percent for stage I, 83.5 percent for stage II, and 72.0 percent for stage III cases. The five-year cumulative local recurrence rate after intersphincteric resection was 2.5 percent. Defecatory function, which was evaluated by bowel movement in a 24-hour period, and continence after intersphincteric resection were objectively good. The results of the multivariate analysis revealed that age was the only factor associated with a risk of fecal incontinence. CONCLUSION: Provided strict selection criteria are used, intersphincteric resection may be the optimal sphincter-preserving surgery for low rectal cancer.

RELATION BETWEEN OBESITY AND ADENOMATOUS POLYPS OF THE LARGE BOWEL

Background:  We compared the prevalence of colorectal adenoma (polyps) in men and women and examined the role of body mass index (BMI) on polyp risk according to patient age and gender.

Usefulness of magnetic resonance imaging for diagnosing deep anorectal abscesses.

PURPOSE: We evaluated the usefulness of magnetic resonance imaging for the preoperative diagnosis of deep anorectal abscesses. METHODS: Subjects were 21 patients with deep anorectal abscesses. Deep anorectal abscesses were classified into two types, ischiorectal and pelvirectal, according to their location. Patients were also classified into a single abscess group, which showed either an ischiorectal or pelvirectal abscess, and a double abscess group, which showed both ischiorectal and pelvirectal abscesses. The final diagnosis was made from surgical findings, and the types of deep anorectal abscesses determined by digital examination and magnetic resonance imaging were compared. RESULTS: Sensitivity of ischiorectal abscesses (20 lesions) with digital examination and magnetic resonance imaging was 75 and 95 percent, respectively, and that of pelvirectal abscesses (10 lesions) with digital examination and magnetic resonance imaging was 60 and 70 percent, respectively. Sensitivity of the magnetic resonance imaging was significantly higher than that of digital examination in ischiorectal abscesses. Diagnostic accuracy of digital examination and magnetic resonance imaging were both 83 percent in the single abscess group (12 patients), whereas in the double abscess group (9 patients) it was 22 and 78 percent, respectively. The rate of accurate diagnosis of magnetic resonance imaging compared with digital examination in the double abscess group was significantly higher than that in the single abscess group. CONCLUSION: Magnetic resonance imaging was useful for diagnosing and differentiating ischiorectal and pelvirectal abscesses.

Clinical investigation of colorectal cancer detected by follow-up colonoscopy after endoscopic polypectomy

PURPOSE: We analyzed the results of a long-term follow-up surveillance of patients with colorectal polyps after endoscopic polypectomy in terms of the cumulative incidence of subsequent colorectal cancer and the clinicopathologic characteristics of carcinomas detected by colonoscopy. METHOD: The study cohort consisted of 6,715 patients who had received endoscopic resection of single or multiple colorectal polyps and then underwent periodic colonoscopy (or a combination of sigmoidoscopy and barium x-ray examination in some cases) during an average follow-up of six years (40,622 person-years in total). RESULTS; During the follow-up, 31 cases of colorectal cancer containing 15 submucosal invasive carcinomas (T1,N0,M0) and 16 advanced carcinomas were detected. The cumulative incidence of colorectal cancer was analyzed for four subgroups of the 6,715 patients classified according to the diameter, grade of dysplasia, and histologic features of polyps. Furthermore, the depth of invasion, macroscopic configuration of submucosal invasive cancer, and site of colorectal cancer observed in the 31 cases were compared with those of a reference group of 1,497 patients with colorectal cancer treated at Takano Hospital during the same period. Submucosal invasive cancer was the most common type among the colorectal carcinomas detected during follow-up. In terms of macroscopic configuration of submucosal cancer, the superficial type was significantly more common than the protruded type. The superficial submucosal cancer showed a significantly longer interval to detection than the protruded submucosal cancer. By site of lesion, proximal colon cancer was significantly more common. CONCLUSION: Follow-up colonoscopy appears to be useful in patients with larger polyps (>5 mm). Patients with severe dysplasia and those with malignant polyps should be followed-up carefully. Because submucosal cancer detected by follow-up examination after polypectomy showed higher rates of superficial-type cancer and proximal colon cancer, careful endoscopic examination of the entire colon is important.

An Analysis of the Development of Colonic Diverticulosis in the Japanese

PURPOSEThere are quite different characteristics between colonic diverticulosis in the West and that in Asia, including Japan. These differences include the predominance of a few diverticula over others, right-sidedness, young generation, male, and few complications. In Japan, colonic diverticulosis started increasing in the 1970s. This study was performed to obtain exact evidence of diverticular development in contemporary Japanese by observing changes in diverticula in the same individuals examined over a period of ten or more years.METHODSThis study included 82 subjects (56 (68 percent) males and 26 (32 percent) females) who underwent barium enema examinations repeatedly for more than ten years from 1982 to 2000. The diverticula were categorized according to their location in the colon: right, left, or bilateral. They were also categorized by whether they appeared individually, were scattered with two to nine diverticula, or were numerous with ten or more diverticula.RESULTSAt the beginning of observation, the most frequent location was the right side (55; 67 percent), followed by bilateral (20; 24 percent) and the left side (7; 9 percent). Ten or more years later, the number on the right side had decreased to 39 (48 percent). The number of bilateral diverticula had increased to 38 (46 percent), and the number on the left had barely changed, to 5 (6 percent). The number of diverticula increased from 253 to 604 (239 percent) in the right and from 380 to 929 (244 percent) in the bilateral. The initially very small number in the left increased from 9 to 48 (533 percent). The data show marked increases in the right and bilateral diverticula, and also the spread from the right side to the left side.CONCLUSIONIn contemporary Japanese, although the right predominated initially, diverticulosis showed a strong tendency to increase and spread from the right to the bilateral. The number of bilateral diverticula also tended to increase. The left did not change much.

Evaluation of pelvic descent disorders by dynamic contrast roentgenography

PURPOSE: For precise diagnosis and rational treatment of the increasing number of patients with descent of intrapelvic organ(s) and anatomic plane(s), dynamic contrast roentgenography of multiple intrapelvic organs and planes is described. METHODS: Sixty-six patients, consisting of 11 males, with a mean age (± standard deviation) of 65.6±14.2 years and with chief complaints of intrapelvic organ and perineal descent or defecation problems, were examined in this study. Dynamic contrast roentgenography was obtained by opacifying the ileum, urinary bladder, vagina, rectum, and the perineum. Films were taken at both squeeze and strain phases. On the films the lowest points of each organ and plane were plotted, and the distances from the standard line drawn at the upper surface of the sacrum were measured. The values were corrected to percentages according to the height of the sacrococcygeal bone of each patient. From these corrected values, organ or plane descents at strain and squeeze were diagnosed and graphically demonstrated as a descentgram in each patient. RESULTS: Among 17 cases with subjective symptoms of bladder descent, 9 cases (52.9 percent) showed roentgenographic descent. By the same token, among the cases with subjective feeling of descent of the vagina, uterus, peritoneum, perineum, rectum, and anus, roentgenographic descent was confirmed in 15 of 20 (75 percent), 7 of 9 (77.8 percent), 6 of 16 (37.5 percent), 33 of 33 (100 percent), 25 of 37 (67.6 percent), and 22 of 36 (61.6 percent), respectively. The descentgrams were divided into three patterns: anorectal descent type, female genital descent type, and total organ descent type. CONCLUSIONS: Dynamic contrast roentgenography and successive descentgraphy of multiple intrapelvic organs and planes are useful for objective diagnosis and rational treatment of patients with descent disorders of the intrapelvic organ(s) and plane(s).

THE ROLE OF COMPUTED TOMOGRAPHY IN MANAGEMENT OF PATIENTS WITH CROHN DISEASE

Twenty-five patients with Crohn disease were studied using computed tomography (CT). Assessment of bowel wall thickening, enlargement of the mesenteric lymph nodes, and clearness of the mesenteric vascular contour was carried out in all patients. Evidence of inflammatory reaction of the mesenteric fat was seen in 23 patients (92%) and fibrofatty proliferation was observed in seven patients (28%). Nine patients underwent surgery when symptoms and signs were severe and of long duration, while 16 patients were treated conservatively. Degree of increase in fat density, clearness of the mesenteric vascular bundles, and enlargement of the mesenteric lymph nodes were seen more frequently in the surgical group of patients. CT shows improvement of inflammatory changes after conservative therapy in some cases. A large pseudodiverticulum, pseudopolyps, and a fistula formation were also observed in some cases. CT is an important diagnostic tool in the management of patients with Crohn disease.

Pudendal canal syndrome and proctalgia fugax

To the Edi tor--I was pleased with the findings that Dr. Takano and colleagues s presented in their study on the origin of proctalgia, because they confirm what I reported in my studies. 2-~ The pudendal canal syndrome, as I demonstrated in seven female patients, is a new clinical entity that presents with a characteristic clinical picture and investigative results. The patient complains of anal pain unrelated to defecation and of perianal numbness and tingling, which do not respond to analgesics. Four patients were incontinent for liquid stools and flatus, five had had difficult deliveries, and two complained of severe straining at defecation. In six patients, perianal sensation was impaired. Rectal neck pressure on voluntary squeezing was subnormal. Electromyography revealed reduced activity of the external anal sphincter in all patients and of the levator muscle in four patients. Pudendal nerve terminal motor latency was increased on both sides. Symptoms and investigative results pointed to the diagnosis of pudendal nerve compression in the pudendal canal. Decompression was performed through the perineal approach: the ischiorectal fossa is entered through a para-anal incision; the inferior rectal nerve is identified and followed to the pudendal nerve; and the roof of the pudendal canal is split open. Impaired sensation improved in five of six patients and control disorders in three of four patients. Rectal neck pressure on voluntary squeezing normalized in six patients. Electromyography of the external sphincter improved in five patients and of the levator ani in all patients. Pudendal nerve terminal motor latency diminished. Pain disappeared in all patients. It could be clearly demonstrated in our further studies into this area that a causative relation exists be tween pudendal nerve entrapment and conditions of fecal incontinence that had been either considered idiopathic 5 or were related to rectal prolapse, ~ because their treatment by pudendal canal decompression attained good results.

Follow-up studies of sphincter-preserving operations for anal fistulas

PURPOSE: This study was designed to evaluate and to compare the outcome of anal fistula surgery using techniques involving minimal sphincter damage (sphincter-preserving) and conventional laying open techniques. PATIENTS AND METHODS: From January 1987 to December 1993, 2,242 patients with anal fistulas were treated surgically, of whom 1,070 had sphincter-preserving operations. These included 530 patients with low intersphincteric fistulas (II L), 116 patients with high intersphincteric fistulas (II H), 73 patients with combined high and low intersphincteric fistulas, 239 patients with transphincteric fistulas (III), and 112 patients with supralevator fistulas (IV). The open method of fistula surgery was used in 1,172 patients. RESULTS: Of 1,070 sphincter-preserving operations, delayed healing occurred in 49 patients (4.6 percent) and recurrent fistula occurred in 32 patients (3 percent). By using the open method in 1,172 patients, delayed healing occurred in 10 patients (0.9 percent) and recurrence of fistula occurred in 23 patients (2 percent). Failure rates increased with increasing depth and complexity of the fistula. CONCLUSION: Sphincter function is better with sphincter-preserving fistula surgery than with the open method, although healing was delayed more commonly in sphincter-preserving operations that with the open methods, and fistula recurrence was similar with the two methods. Choice of operation depends on depth of fistula, outcome by manometry, and history of former operations.