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Dive into the research topics where Robert D. Riether is active.

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Featured researches published by Robert D. Riether.


Diseases of The Colon & Rectum | 1994

Is simple fistula-in-ano simple?

Yash Pal Sangwan; Les Rosen; Robert D. Riether; John J. Stasik; James A. Sheets; Indru T. Khubchandani

PURPOSE: A study of 523 fistulas of cryptoglandular origin operated on between January 1985 and December 1991 at the Lehigh Valley Hospital was undertaken for the purpose of establishing whether the “so-called” simple fistula-in-ano has a favorable outcome. High transsphincteric fistulas with or without high blind track, suprasphincteric, extrasphincteric, and horseshoe fistulas as well as fistulas associated with inflammatory bowel disease were excluded. METHODS: Four-hundred sixtyone patients with anal fistulas classified as simple fistulasin-ano (uncomplicated transsphincteric, low and high blind track intersphincteric) were studied retrospectively. There were 310 males and 151 females with an average age of 42 years and mean follow-up of 34 months. RESULTS: Thirty (6.5 percent) patients developed recurrent fistulas: 16 (53.3 percent) beacuse of missed internal openings at initial surgery, six (20 percent) attributed to missed secondary tracks, five (16.7 percent) because of premature fistulotomy wound closure, and three (10 percent) because of miscellaneous factors. CONCLUSION: All so-called simple fistulas-in-ano may not have readily detectable primary openings and may possess secondary tracks which preclude their behavior as simple fistulas.


Diseases of The Colon & Rectum | 2001

Readmissions after colorectal surgery cannot be predicted.

Khawaja Azimuddin; Lester Rosen; James F. Reed; John J. Stasik; Robert D. Riether; Indru T. Khubchandani

INTRODUCTION: Readmission after discharge from the hospital is an undesirable outcome. In an attempt to prevent unplanned readmissions after abdominal or perineal colon resection, we proposed to identify risk factors associated with return to the hospital. METHODS: Study participants consisted of 249 patients who were operated on from July 1, 1996, to March 30, 1998. All patients who were readmitted within 90 days of discharge from the hospital after surgery were evaluated for the study. A retrospective review of charts was performed to assess whether readmission within 90 days was a direct consequence of the recent operation (unplanned related readmission). These patients were compared with a control group consisting of patients who were never readmitted or who were readmitted with an unrelated problem. RESULTS: Of the 249 patients, 59 (24 percent) were readmitted within 90 days of discharge from the hospital. Twenty-two (9 percent) were unplanned related readmissions. Ten patients were readmitted with unrelated emergencies, and 27 patients were readmitted electively. In the unplanned related group, there was no correlation between age, gender, admission diagnosis, activity status, or postoperative length of stay and the likelihood of readmission. Patients with multiple chronic medical problems or those who developed postoperative complications did not have a higher readmission rate. Patients with ulcerative colitis or those who underwent abdominoperineal resection or total/subtotal colectomy had a higher incidence of readmissions, although the difference was not significant. The mean interval between discharge from the hospital and readmission with a related complication was 19 days. Small-bowel obstruction was the most common reason for readmission, and all cases resolved with conservative management. Mean length of stay during all readmissions was 8 days. CONCLUSION: The incidence of unplanned related readmissions 90 days after abdominal or perineal colon resection is 9 percent, and these readmissions could not be predicted from the postoperative course. Because 82 percent of unplanned readmissions occurred within 30 days, this time frame is suitable for computerized comparative analysis.


Diseases of The Colon & Rectum | 1999

Neoplasia after ureterosigmoidostomy

Khawaja Azimuddin; Indru T. Khubchandani; John J. Stasik; Lester Rosen; Robert D. Riether

PURPOSE: The occurrence of neoplasia after ureterosigmoidostomy is well-documented in the literature. Because of its rarity, few general surgeons will gain significant exposure to this entity, and colorectal surgeons are likely to be involved with the care of these patients. The purpose of this article is to apprise colorectal surgeons about the management of neoplasia after ureterosigmoidostomy and to familiarize them with the unique anatomy of the reconstructed pelvis. METHODS: We performed a MEDLINE search to identify articles on ureterosigmoid tumors. The theories regarding the cause and pathology of these tumors were critically analyzed. A consensus was developed for screening patients with ureterosigmoidostomy and for treatment of neoplasia. RESULTS: The incidence of carcinoma after ureterosigmoidostomy ranges from 2 to 15 percent. Polyps are more common, and it seems that these tumors also follow the sequence of adenocarcinoma that is seen in the common variety of colorectal neoplasia. Neoplastic changes begin with the interaction of urine and feces and the healing colonic mucosa. Both production of nitrosamines by the action of bacteria on urine and DNA damage caused by reactive oxygen radicals produced by neutrophils at the healing anastomosis have been implicated in the pathogenesis of neoplasia. The latent period between formation of ureterosigmoidostomy and the appearance of carcinoma is between 20 and 26 years. Obstructive urinary symptoms that develop more than two years after ureterosigmoidostomy should be viewed with suspicion. The patient should be investigated with a CT scan and colonoscopy, and a barium enema may be required to delineate the anatomy further. If a benign tumor is encountered during colonoscopy, it may be removed by snare polypectomy. For a malignant tumor the segment of colon with ureteric implants should be excised, along with its lymphatic drainage. Bowel continuity is restored primarily, and the ureters are implanted in an ileal conduit. CONCLUSIONS: Patients with ureterosigmoidostomy should be followed closely for the rest of their lives. The aim of screening is to identify and treat neoplasia before malignancy develops. Furthermore, early detection of neoplasia by close screening will improve survival. Although urine cytology and occult blood are inexpensive tests, colonoscopy remains the criterion standard for follow-up of these patients. Annual colonoscopic surveillance should be started soon after the ureterosigmoidostomy but not later than five to six years after the procedure. Patients who are noncompliant with the vigorous follow-up schedule should be offered the option of resection of the colonic segment at risk with urinary diversion.


Diseases of The Colon & Rectum | 1999

Colorectal cancer after surveillance colonoscopy: False-negative examination or fast growth?

Tito F. Gorski; Lester Rosen; Robert D. Riether; John J. Stasik; Indru T. Khubchandani

PURPOSE: Colonoscopy is the preferred method for colorectal cancer surveillance of high-risk patients. Despite its high sensitivity, polyps or cancers may be undetected by colonoscopy and later attributed to an accelerated adenoma-carcinoma sequence. This study assesses how the characteristics of colorectal cancers found at intervals between surveillance relate to the adenoma-carcinoma sequence and its prevention. METHODS: The records of 557 patients with colorectal cancer that were diagnosed from January 1, 1990, to December 31, 1996, were reviewed to identify those patients who had prior colonoscopic surveillance within 60 months of their diagnosis. RESULTS: There were 29 (5.2 percent) patients who had one or more colonoscopies before diagnosis of their colorectal cancer. Mean interval between diagnosis and prior colonoscopy was 23 (range, 4–59) months. The distribution of cancers included nine cecum, two ascending, three hepatic flexure, five transverse, one splenic flexure, three descending, two sigmoid, three rectum, and one anal canal. The mean tumor size was 4.4 cm for the cecum and 2.4 cm for all other locations. There were 7 Tis, 6 T1, 4 T2, and 12 T3 lesions. Six patients with T3 lesions had prior colonoscopies within 24 months of the diagnosis. Three of four patients with lymphatic metastases had tumors in the cecum. Twenty tumors (69 percent) were well or moderately differentiated. Mean follow-up was 41 (range, 7–95) months with two local recurrences and two unrelated deaths. CONCLUSIONS: Size, differentiation, and stage of colorectal cancer in addition to the interval to diagnosis suggest that the majority of cancers found during surveillance colonoscopy followed prior false-negative examinations. Because cecal landmarks are most constant, prior photographic documentation may help to prove or disprove fast growth of cancers found in the cecum during surveillance colonoscopy.


Diseases of The Colon & Rectum | 1986

Management of anorectal horseshoe abscess and fistula.

Douglas Held; Indru T. Khubchandani; James A. Sheets; John J. Stasik; Lester Rosen; Robert D. Riether

Over a 10-year period 69 patients were treated consecutively for posterior and anterior horseshoe abscesses and fistulas. Fifty-nine patients had posterior and ten had anterior abscesses or fistulas. There were 52 patients with acute abscess. Treatment consisted of incision and drainage, incision and drainage with primary fistulotomy, incision and drainage with primary fistulotomy and counter-drainage, and incision and drainage with insertion of seton. Seventeen patients with chronic fistulas were treated by primary fistulotomy with curettage, or incision and drainage with insertion of seton. Patients were followed from three months to ten years with a mean follow-up of three years. No incidences of incontinence were reported in this series. The overall rate of recurrence was 18 percent, and included only patients with posterior abscesses and fistulas. Recurrence was related to the failure to maintain prolonged drainage in the midline after primary fistulotomy. The use of seton for delayed fistulotomy appears to promote wound drainage and precludes premature wound closure. More liberal use of the seton in the treatment of horseshoe abscesses and fistulas is advocated.


Diseases of The Colon & Rectum | 1991

Hemorrhoidectomy during pregnancy : risk or relief ?

Richard G. Saleeby; Lester Rosen; John J. Stasik; Robert D. Riether; James A. Sheets; Indru T. Khubchandani

Acute hemorrhoidal crisis can occur in the pregnant female. When medical therapy fails to relieve pain, operative intervention may be necessary. The surgeon, however, may be reluctant to operate due to potential complications to the mother and fetus. From July 1983 to July 1989, hemorrhoidectomy was performed in 25 of 12,455 pregnant women (0.2 percent) who delivered in our institution. Twenty-two women were in their third trimester, 80 percent were multiparous, and each had a remote history of hemorrhoidal symptoms, including intermittent pain, bleeding, and protrusion. Closed hemorrhoidectomy was performed under local anesthesia. The surgery was directed at removing only symptomatic disease, which included three quadrants in 14 patients, two quadrants in seven patients, and one quadrant in four patients. All patients experienced relief of intractable pain the day after surgery, except one patient who required a hemostatic packing during the immediate postoperative period. There were no other maternal or fetal complications. Subsequent follow-up for anorectal disease ranged from 6 months to 6 years. Six (24 percent) patients required additional hemorrhoid treatment. Hemorrhoidectomy in selected pregnant patients is safe in our experience.


Diseases of The Colon & Rectum | 1997

Value of carcinoembryonic antigen monitoring in curative surgery for recurrent colorectal carcinoma

Paul A. Lucha; Lester Rosen; Judith A. Olenwine; James F. Reed; Robert D. Riether; John J. Stasik; Indru T. Khubchandani

PURPOSE: This study is designed to review a carcinoembryonic antigen (CEA)-driven postoperative protocol designed to identify patients suitable for curative reresection when recurrent colorectal cancer is identified. METHODS: A total of 285 patients who were operated on for colon or rectal carcinoma between 1981 and 1985 were evaluated (with CEA levels) every two months for the first two years, every three months for the third year, every six months for years 4 and 5, and annually thereafter. CEA levels above 5 μg were considered abnormal and were evaluated with diagnostic imaging and/or endoscopy. RESULTS: Follow-up was available for 280 patients (98.2 percent). Distribution of patients by Astler-Coller was: A, 14 percent; B1 20 percent; B2, 39 percent; C1, 5 percent; C2, 21 percent. There were 62 of 280 patients (22 percent) who developed elevated CEA levels, with 44 patients who demonstrated clinical or radiographic evidence of recurrence. Eleven patients were selected for surgery with curative intent (4 hepatic resections, 1 pulmonary wedge resection, 2 abdominoperineal resections, 2 segmental bowel resections, and 2 cranial metastasectomies). Three of 11 patients (27 percent) benefited and have disease-free survivals greater than 60 months. Of the 223 patients without elevated CEA, 22 (9.9 percent) had recurrent cancer without any survivors. Overall, 3 of 285 patients (1.1 percent) were cured as a result of CEA follow-up. CONCLUSION: CEA-driven surgery is useful in selected patients and can produce long-term survivors.


Diseases of The Colon & Rectum | 1993

Outcome of delayed hemorrhage following surgical hemorrhoidectomy

Les Rosen; Paul Sipe; John J. Stasik; Robert D. Riether; Howard D. Trimpi

Delayed hemorrhage following surgical hemorrhoidectomy is a well-recognized complication. Emergency treatment may include suture ligation, anal packing, or other means of tamponade. At the Lehigh Valley Hospital, 27 patients were seen with the complication of delayed hemorrhage over an eight-year period from 1983 to 1990, for an incidence of 0.8 percent. Twenty-five patients (93 percent) underwent surgery primarily for hemorrhoidal disease; one patient had hemorrhoids removed in addition to a sphincterotomy for anal fissure, and the remaining patient had hemorrhoidectomy with fistulotomy. The mean interval from the operation to hemorrhage was six days. Treatment modalities included bedside anal packing in 20 patients (74 percent), observation alone in five patients (18 percent), and suture ligation in the operating room in two patients. Anal packing was successful in controlling postoperative hemorrhage in 20/20 patients, but late complications requiring reoperation developed in 15 percent.


Diseases of The Colon & Rectum | 2000

Hyperplastic polyps: “more than meets the eye”?: Report of sixteen cases

Khawaja Azimuddin; John J. Stasik; Indru T. Khubchandani; Lester Rosen; Robert D. Riether; Michael Scarlatto

The vast majority of hyperplastic polyps are small, left-sided, and inconsequential in nature. However, hyperplastic polyps that are large, right-sided, mixed, and found in association with a family history of carcinoma may represent an “atypical” group, and their clinical significance is uncertain. We believe that these atypical lesions should not be lumped together with the common variety of diminutive hyperplastic polyps. Rather, when such hyperplastic polyps are encountered, they should be excised and the patient should be placed on regular colonoscopic surveillance.


Cancer | 1986

Comparing predictive decision rules in postoperative CEA monitoring

Frederick Denstman; Lester Rosen; Indru T. Khubchandani; James A. Sheets; John J. Stasik; Robert D. Riether

To evaluate the usefulness of serial postoperative carcinoembryonic antigen (CEA) assays, seven previously published decision rules for predicting tumor recurrence were compared retrospectively using CEA values from 214 patients followed 36 to 120 months after surgery for colorectal carcinoma. Decision rules employing cutoff values to predict tumor recurrence were found inadequate for the asymptomatic patient. This attenuation of prognostic usefulness appeared attributable to inadequacies of CEA assays for predicting late recurrences. From these analyses, elevated CEA results without other objective evidence might be insufficient to justify second‐look surgery. In addition, late recurring tumors tended not to cause elevated CEA levels.

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John J. Stasik

Providence Sacred Heart Medical Center and Children's Hospital

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Les Rosen

Lehigh Valley Hospital

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