PubMed Health⌕ Search

Biomedical subjects

Nir Wasserberg

Publications and source records attributed to Nir Wasserberg.

17 recordsLinked to original sources
PubMed2026

Short-Term Success, Long-Term Failure: Strain Turnover and Virulence Re-Emergence May Drive Relapse in Pouchitis.

BACKGROUND & AIMS: Pouchitis, de-novo small intestinal inflammation is the most common complication developing in patients with ulcerative colitis after total large bowel resection and ileal pouch-anal anastomosis (IPAA) reconstruction. While the first line treatment is antibiotics, the microbial properties underlying flare, remission, and relapse remain vague. We aimed to investigate how antibiotic treatment drives microbial shifts that underlie remission and contribute to relapse. METHODS: Patients after IPAA were prospectively recruited during clinical flare (active pouchitis defined by the pouchitis disease activity index) and received a two-week course of metronidazole with either ciprofloxacin or doxycycline. Longitudinal follow up was conducted during a year. Clinical data were recorded, and fecal samples were obtained during consequent flares, recovery, and relapses. Microbial gene repertoire, strains, and resistance to antibiotics were determined. Metagenomic sequencing was integrated with whole-genome sequencing of Escherichia coli isolates, providing strain-specific virulence and antibiotic resistance profiles. RESULTS: Patients (n=21) recruited provided 130 samples over one-year follow-up. Both antibiotic regimens induced rapid but transient clinical improvement, reflected by a decrease in fecal calprotectin (728 to 265 &#x3bc;g/g, p<.05), and a marked reduction in bacterial exotoxin genes (p<.05), yet both parameters rebounded by 6 weeks post-treatment. Antibiotic resistance gene abundance significantly increased during treatment (p<.05), without expansion of resistance gene diversity, indicating that pre-existing resistant strains increased. CONCLUSIONS: Antibiotic-induced remission in pouchitis likely results from a temporary suppression of exotoxin-producing bacteria, enabling resistant, low-virulence strains to transiently dominate; The fact that harmful strains quickly rebound after treatment cessation highlights the need for targeted approaches to achieve sustained microbial control.

Inflammatory bowel disease↗
PubMed2007

Pseudoaneurysm of the inferior gluteal artery: an unusual complication after abdominoperineal resection for rectal cancer. Report of a case.

We report an unusual case of profuse, sporadic hemorrhage from a chronically infected perineal wound after an abdominoperineal resection. Surgical exploration and angiography on two occasions failed to identify the source of bleeding. A pseudoaneurysm of the internal iliac artery was eventually identified with a provocative angiogram using tissue plasminogen activator. This aneurysm was successfully treated with embolization with coils.

Aneurysm, False↗
PubMed2006

Incidence and management of colonoscopic perforations: 8 years' experience.

AIM: To review the experience of a major medical teaching center with diagnostic and therapeutic colonoscopies and to assess the incidence and management of related colonic perforations. METHODS: All colonoscopies performed between January 1994 and December 2001 were studied. Data on patients, colonoscopic reports and procedure-related complications were collected from the departmental computerized database. The medical records of the patients with post procedural colonic perforation were reviewed. RESULTS: A total of 120067 colonoscopies were performed during the 8 years of the study. Seven colonoscopic perforations (4 females, 3 males) were diagnosed (0.058%). Five occurred during diagnostic and two during therapeutic colonoscopy. Six were suspected during or immediately after colonoscopy. All except one had signs of diffuse tenderness and underwent immediate operation with primary repair done in 4 patients. No deaths were reported. CONCLUSION: Perforation rate during colonoscopy is low. Nevertheless, it is a serious complication and its early recognition and treatment are essential to optimize outcome. In patients with diffuse peritonitis early operative intervention makes primary repair a safe option.

Adult↗
PubMed2005

Preservation of bowel and urinary continence in the management of locally recurrent rectal cancer.

BACKGROUND: The management of locally recurrent rectal cancer should achieve local tumor control and potentially improving disease-free and overall survival. Radical pelvic resection has traditionally been associated with permanent fecal and urinary diversion. However, as advanced techniques have evolved to allow restoration of intestinal and urinary continence, we reviewed the use of these techniques in patients with recurrent rectal cancer. METHODS: Patients with recurrent rectal cancer who underwent a resection at Norris Comprehensive Cancer Center between 1993 and 1999 were retrospectively reviewed. Data collected included demographic data, surgical and oncological history, patterns of recurrence, treatment modalities, and outcome. Follow-up data was obtained from the last clinic visit and/or tumor registry. RESULTS: Sixty-seven patients with locally recurrent rectal cancer (male/female 45/22, age 32-81 years) were included in the analysis. Continence was re-established in 22 (33%) patients, urinary continence was restored in 12 patients, and intestinal continuity in 14 patients (both in 4 patients). A temporary diverting ostomy was necessary in 5 out of 14 (36%) patients. Mortality was zero and morbidity was low and included two urinary leaks and one fecal leak all of which could be managed non-operatively. At a median follow-up of 16 months (range 5-55), 11 (50%) patients were still alive, 7 (31%) without evidence of disease. Comparison of the groups of patients either with or without continence preservation showed no statistically significant difference in disease-free survival and overall survival rates. High quality of life was achieved with restoration of continuity, no patient with restored continuity expressed a desire for a diversion. CONCLUSION: If an oncologically adequate resection of the recurrent rectal cancer can be performed without impairment of the pelvic floor integrity, continence preservation is feasible and results in good functional and oncological outcome.

Adult↗
PubMed2005

Fistula-in-ano: do antibiotics make a difference?

BACKGROUND: The objective of this study was to evaluate the hypothesis that antibiotics in conjunction with drainage of anorectal abscesses will reduce the incidence of fistulae formation. The impact of age and associated comorbidity on the formation of fistulae were also evaluated. METHODS: Patients with a diagnosis of anorectal abscesses were identified from the database of a single colorectal practice. Demographic data, comorbidity, antibiotic usage, and fistulae formation were collected from review of patient's charts and phone contact. Statistical analysis was performed with the two-sided Fisher's exact and Wald's chi-square tests. RESULTS: Fifty-six patients with complete data were analyzed. The overall fistulae formation rate was 32%. Of all patients, 45% received a course of broad-spectrum antibiotics at the time of drainage and 48% of patients had associated comorbidity. Although trends were evident, there were no statistical significant associations between fistulae formation and age, comorbidity, and antibiotics. CONCLUSION: Although not statistically significant, there was a trend that antibiotics and age >45 years may be protective against the formation of fistulae. Similarly, the data suggest that the presence of comorbidity may increase the risk of fistula formation. We are encouraged by this result and propose to conduct a larger randomized prospective study.

Abscess↗
PubMed2004

Colonoscopic perforation and bleeding of the colon can be treated safely without surgery.

The incidence of colonoscopic perforation of colon is about 0.3 per cent. The incidence of colonoscopic bleeding is about 0.6 per cent. Many of those patients undergo unnecessary operations. In order to assess the outcome of nonoperative management of those patients with postcolonoscopic perforation and bleeding, the records of 5120 patients who underwent colonoscopies from September 1, 1988 to June 30, 2003 were retrospectively reviewed with attention paid to colonoscopic perforation and bleeding. Their symptoms, management, and outcome were reviewed. There were 2765 male and 2355 female patients. Ages ranged from 9 to 91 years. A total of 1902 patients (37.1%) had polyps removed. Six patients (0.1%) had colonoscopic perforation. All of them presented with abdominal pain 1 to 4 days after colonoscopic polypectomy. All had subphrenic free air or subcutaneous emphysema on the radiogram. All were treated nonoperatively with nothing by mouth and intravenous fluids and antibiotics in the hospital and recovered uneventfully. Six patients (0.1%) had colonic bleeding that occurred 1 to 14 days after colonoscopic polypectomy. All of them were managed by repeat colonoscopy with injection of epinephrine. All recovered without further bleeding. Therefore, postcolonoscopic perforation and bleeding can be treated nonoperatively. It is safe and cost effective. The mortality and morbidity are very low.

Adolescent↗
PubMed2003

Anastomotic healing in a small bowel transplantation model in the rat.

Anastomotic healing is impaired after intestinal surgery because of ischemia and reperfusion injury (IRI), which can result in intestinal leaks leading to increased mortality. The objective of this study was to determine the effects of transplant IRI and immune mechanisms on intestinal graft anastomotic healing. Orthotopic intestinal transplantations (OIT) were performed in rats. The experimental design consisted of six groups A-F (n=5/group): A, allogeneic OIT treated with tacrolimus (1 mg/kg/day); B, syngeneic OIT treated with tacrolimus; C, syngeneic OIT; D, allogeneic OIT; E, proximal and distal anastomoses performed in nontransplanted animals; F, same as in group E but treated with tacrolimus. Anastomotic bursting pressure (ABP), hydroxyproline content (HPC), and mucosal inflammatory infiltrate (MII) were determined at the anastomotic sites (proximal and distal) and compared between groups. ABP was significantly (p<0.001) reduced in OIT groups A, B, C, and D compared to control groups E and F at both the proximal and distal anastomotic sites. HPC was approximately 1 microg/mg of tissue in groups A, B, C, and D, and approximately 5 microg/mg of tissue in groups E and F. This demonstrates a significant (p<0.001) reduction in HPC after OIT. MII was significantly (p<0.001) increased in OIT groups when compared to nontransplanted control groups. MII was also significantly (p<0.05) increased in allogeneic OIT groups A and D compared to syngeneic OIT groups B and C. Generally, ABP and HPC were inversely proportional to MII in both nontransplanted control and OIT groups. Reduced anastomotic strength was demonstrated in both syngeneic and allogeneic OIT anastomotic sites irrespective of immunosuppressive therapy, and is probably related to IRI.

Anastomosis, Surgical↗
PubMed2003

Expression of MUC2 and MUC4 proteins and cytokines: early markers of intestinal graft rejection.

BACKGROUND: Histopathologic examination (HP) is the primary method of monitoring intestinal graft rejection. Alterations in mucin levels have been demonstrated in bowel diseases. The aim of this study was to detect early markers of intestinal graft rejection based on mucin and cytokine levels. METHODS: Allogeneic and syngeneic orthotopic intestinal transplantations were performed in untreated Lewis strain recipient rats from Dark Agouti and Lewis strain donors, respectively (unmodified rejection and nonrejection groups). Similarly, allogeneic and syngeneic orthotopic intestinal transplantations were performed in tacrolimus (immunosuppression)-treated groups. HP was performed on hematoxylin-eosin and periodic acid Schiff-stained sections. Expression of MUC2 and MUC4 proteins and of mRNA was detected by immunohistochemistry and Northern analysis, respectively. Interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, and transforming growth factor-beta(1) were measured by reverse transcription-polymerase chain reaction. RESULTS: HP revealed early or mild rejection on day 3, moderate rejection on day 5, and severe rejection on day 7 posttransplantation (posttx) in the unmodified rejection group. A significant (P<0.01) increase in MUC2 and MUC4 expression was observed on day 3 posttx in the allogeneic rejection group compared with syngeneic controls; the levels decreased by day 7. Goblet cells were significantly more frequent on day 3 compared with days 5 and 7 posttx (P<0.01). IFN-gamma and TNF-alpha expression were also higher in the rejection group. CONCLUSIONS: Early transplant rejection is associated with increased MUC2, MUC4, IFN-gamma, and TNF-alpha expression. These markers combined with HP may assist in the diagnosis of early intestinal graft rejection.

Animals↗
PubMed2003

Are solitary breast papillomas entirely benign?

HYPOTHESIS: Solitary breast papillomas are potentially malignant and are associated with a higher risk of breast cancer. DESIGN: Retrospective review of all pathological reports containing breast papilloma (1983-2000) and review of selected specimens. SETTING: Tertiary, referral, university-affiliated medical center. PARTICIPANTS: Ninety-five women with a breast specimen containing a papilloma or papillomatosis. Patients with overt papillary carcinoma without papilloma were excluded. INTERVENTION: All histopathological characteristics of the papilloma and the surrounding tissue were noted. The incidence of malignant and other proliferative histopathological findings were analyzed, comparing solitary ductal papilloma cases to multiple papilloma cases. The Fisher exact test and chi2 test were applied for statistical analysis. MAIN OUTCOME MEASURES: Surgical removal of solitary ductal papillomas should include margins wide enough to secure removal of any proliferative tissue within or around the papilloma and to enable thorough evaluation of the risk for future breast cancer. RESULTS: Solitary papillomas were associated with breast carcinoma in 7 patients (10%) in this series. An additional 9% (n = 6) presented with invasive or noninvasive carcinoma within the papilloma. Atypical papilloma was noted in 6% of patients (n = 4). The risk of associated malignancy was not significantly different between solitary ductal papilloma and multiple papilloma. CONCLUSION: Increased risk of breast cancer is associated with all forms of papilloma.

Adult↗
PubMed2003

Surgical clip found in duodenal ulcer after laparoscopic cholecystectomy.

The wide use of surgical clips in laparoscopic surgery has led to a variety of complications. We describe two cases in which a surgical clip was incorporated into a duodenal ulcer after laparoscopic cholecystectomy. The presenting symptom was acute gastrointestinal bleeding. Both patients were treated endoscopically, and the bleeding stopped after the clip was removed from the ulcer base. Although the mechanism by which a surgical clip migrates into the duodenum is unclear, we recommend meticulous Calot's triangle dissection and removal of any wandering or misplaced clips. Endoscopic removal is recommended when a surgical clip is discovered in a bleeding ulcer.

Aged↗
PubMed2003

Laparoscopic repositioning of Heliogast gastric band after anterior slippage.

BACKGROUND: Gastric slippage is a well-described complication of gastric banding. The Heliogast band is equipped with a locking mechanism that enables its straightforward reopening and repositioning. Our experience with Heliogast band salvage after anterior slippage is reported. METHODS: The study sample comprised 418 consecutive patients who underwent 2-step laparoscopic gastric banding with the Lap-Band first (n=235) followed with the Heliogast band (n=183). Gastric slippage was diagnosed by symptoms of dysphagia and vomiting and was confirmed with Gastrografin swallow. Patients who did not respond to conservative treatment were laparoscopically reoperated. In the Heliogast group, the band was dissected free, unlocked, and repositioned. In the Lap-Band group, when reopening proved impossible, the band was removed with or without replacement. RESULTS: 10 patients (2.4%) underwent reoperation for anterior slippage, 5 with a Lap-Band (2.1%) and 5 with a Heliogast band (2.7%). Band repositioning was feasible in all 5 patients in the Heliogast group, but in only one of the patients in the Lap-Band group; in the others, the band was removed. Band repositioning was confirmed radiologically. No postoperative complications were recorded, and all patients were discharged on the first day after surgery. At a median 10 months' follow-up after Heliogast repositioning, all patients had satisfactory weight loss. CONCLUSION: Laparoscopic Heliogast band salvage after anterior slippage is comparatively simple and safe, with excellent postoperative results and no interference with continued weight loss. This constitutes an important means of management for the bariatric surgeon.

Adult↗
PubMed2002

Risk factors for lymph node metastases in breast ductal carcinoma in situ with minimal invasive component.

HYPOTHESIS: Clinical and pathological variables may be predictors of axillary dissemination in T1mic and T1a breast carcinoma. DESIGN: Retrospective medical chart review. SETTING: University-affiliated tertiary referral center. PATIENTS: All patients diagnosed as having ductal carcinoma in situ (DCIS) with microinvasion between January 1, 1988, and December 30, 1998. MAIN OUTCOME MEASURES: Pathology slides were reviewed according to the 1997 Cancer Staging Manual put forth by the American Joint Committee on Cancer. The number of involved ducts was noted. Patients with no invasive component or invasive components larger than 5 mm were excluded. Pathological and clinical variables were analyzed for their effect on axillary lymph node metastases. RESULTS: The study group included 57 women aged 37 to 71 years (median, 60 years), 37 with T1mic disease and 20 with T1a. Modified radical mastectomy was performed in 29 patients (18 with T1mic and 11 with T1a) and breast-preserving surgery in 28 (19 with T1mic and 9 with T1a). Forty-three patients (28 with T1mic and 15 with T1a) underwent axillary lymph node dissection. Axillary involvement was detected in 3 patients in each group. Forty-seven patients received adjuvant therapy (radiotherapy alone, or with hormones or chemotherapy). Follow-up was 3 to 120 months (median, 40 months). One patient was unavailable for follow-up, another died of disseminated disease, and a third developed contralateral primary carcinoma. Comedo DCIS (P<.03) and the number of DCIS-involved ducts (P<.002) in the T1mic group, and nuclear grade 3 (P<.001) in both groups, were independent significant predictors of axillary metastases. CONCLUSIONS: The significant rate of axillary metastases in T1a and T1mic breast tumors makes axillary staging a must. High nuclear grade, comedo DCIS, and high number of DCIS-involved ducts may predict axillary metastasis and should be considered when axillary dissection is done selectively.

Adult↗