Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Hermann Kessler is active.

Publication


Featured researches published by Hermann Kessler.


Diseases of The Colon & Rectum | 2010

Complete clinical response after neoadjuvant chemoradiation therapy for distal rectal cancer: characterization of clinical and endoscopic findings for standardization.

Angelita Habr-Gama; Rodrigo Oliva Perez; Gregory Wynn; John H. Marks; Hermann Kessler; Joaquim Gama-Rodrigues

BACKGROUND: Complete tumor regression may develop after neoadjuvant chemoradiation therapy for distal rectal cancer. Studies have suggested that selected patients with complete clinical response may avoid radical surgery and close surveillance may provide good outcomes with no oncologic compromise. However, definition of complete clinical response is often imprecise and may vary between different studies. The aim of this study is to provide a clear definition for a complete clinical response after neoadjuvant chemoradiation therapy in patients with distal rectal cancer in addition to actual endoscopic videos from patients managed nonoperatively. METHODS: Patients with nonmetastatic distal rectal cancer treated by neoadjuvant chemoradiation therapy, including 50.4 Gy and concomitant 5-fluorouracil and leucovorin, were assessed for tumor response at least 8 weeks after chemoradiation therapy completion. Complete and incomplete clinical responses were defined based on clinical and endoscopic findings. Patients with complete clinical response were not immediately operated on and were closely followed. Early and late endoscopic findings were recorded. RESULTS: Definition of a complete clinical response should be based on very strict clinical and endoscopic criteria. The finding of any residual superficial ulceration, irregularity, or nodule should prompt surgical attention, including transanal full-thickness excision or even a radical resection with total mesorectal excision. Standard or incisional biopsies should be avoided in this setting. Complete clinical responders should harbor no more than whitening of the mucosa, teleangiectasia with mucosal integrity to be considered for a nonoperative approach. In the presence of these findings, regularly scheduled reassessments may provide a safe alternative to these patients with early detection of recurrent disease. CONCLUSION: Strict definition of the clinical and endoscopic findings of patients experiencing complete clinical response after neoadjuvant chemoradiation therapy may provide a useful tool for the understanding of outcomes of patients managed with no immediate surgery allowing standardization of classifications and comparison between the experiences of different institutions.


Surgical Endoscopy and Other Interventional Techniques | 1999

Laparoscopic management of colorectal endometriosis

B. L. Jerby; Hermann Kessler; T. Falcone; Jeffrey W. Milsom

AbstractBackground: In the past, intestinal endometriosis diagnosed at laparoscopy has generally required conversion to conventional surgery. The purpose of this study was to describe the laparoscopic management of colorectal endometriosis at a tertiary referral center. Methods: From November 1994 to March 1998, 509 consecutive patients with endometriosis requiring laparoscopic intervention were prospectively evaluated. Those with colorectal involvement were analyzed for stage of disease, procedure, operative time, conversion rate, length of hospitalization, and complications. Results: In 30 of the 509 patients (5.9%), colorectal involvement was identified. Twenty-eight of these 30 had stage IV disease. Intestinal involvement was suspected preoperatively in 13 of 30. Twelve required superficial excision of colon or rectal endometriomas. Protectomy/proctosigmoidectomy was done in seven cases, and rectal disc excision was performed in five patients. Four cases required conversion due to the overall severity of the pelvic disease. For those who did (n= 12) and did not (n= 18) require full-thickness excisions/resections, the median operative time was 180 min (range, 90–390) and 110 min (range, 45–355), respectively; the median length of hospitalization was 4 days (range, 3–7) and 1 day (range, 0–4), respectively. A major complication occurred in one patient (colovaginal fistula). At a median follow-up of 10 months (range 1–32), 28 patients were improved, and 24 of these had near or total resolution of preoperative symptoms. Conclusions: Extensive pelvic endometriosis generally requires rectal disc excision or bowel resection. In our experience, laparoscopic treatment of colorectal endometriosis, even in advanced stages, is safe, feasible, and effective in nearly all patients.


Diseases of The Colon & Rectum | 2005

Tumor Site Predicts Outcome After Radiochemotherapy in Squamous-Cell Carcinoma of the Anal Region: Long-Term Results of 101 Patients

Gerhard G. Grabenbauer; Hermann Kessler; Klaus E. Matzel; Rolf Sauer; Werner Hohenberger; Ignaz Schneider

PURPOSEThis study was designed to assess the long-term results following radiochemotherapy in patients with anal squamous-cell carcinoma and to evaluate the impact of tumor location on response, survival, and colostomy-free survival.PATIENTS AND METHODSBetween 1985 and 2001, a total of 101 patients with anal carcinoma were registered for curative treatment, of whom 77 had involvement of the anal canal alone, 10 cases had extension into the perianal skin, and 14 patients had pure anal margin tumors. Small tumors of the anal margin were not included since they were treated by surgical excision only. Among the 101 patients were 74 women and 27 men with a median age of 62 (range, 26–84) years. T categories (International Union against Cancer) were T1 (15), T2 (36), T3 (34), and T4 (16). Seventy-one patients had no evidence of nodal disease, whereas 30 presented with involved regional nodes. Radiation treatment was directed to the primary tumor region and to the inguinal, perirectal, and internal iliac nodes using a three-field to four-field box technique with 10MV photons up to a total dose of 5040 cGy. Lesions greater than 5 cm received an additional boost by interstitial or external radiation depending on circumferential extension of the residual tumor. All patients were scheduled for simultaneous chemotherapy with two cycles of 5-fluorouracil at a dose of 1000 mg/m 2/day as 120 hours of continuous intravenous infusion on Days 1 to 5 and 29 to 33 and mitomycin C at 10 mg/m 2/day on Days 1 and 29. Median follow-up time was was 7.5 (range, 1–16) years.RESULTSOverall survival and colostomy-free survival rates for patients with anal canal cancer were 75 percent and 87 percent at five years, respectively. Patients with anal margin cancer had a less favorable outcome with five-year-overall and colostomy-free survival rates of 54 percent and 69 percent, respectively. After correction for imbalance between anal canal and anal margin tumors, i.e., exclusion of T1 tumors of the anal canal, difference in overall survival remained significant (73 percent vs. 54 percent, P = 0.01). Following multivariate analysis, tumor location (anal canal vs. anal margin, P = 0.02), age (P = 0.003), and dose intensity of chemotherapy (≤75 percent vs. >75 percent, P = 0.03) remained independent significant factors for overall survival. Initial tumor response at six weeks (P = 0.03) was predictive for colostomy-free survival.CONCLUSIONSWith colostomy-free survival rates around 85 percent, long-term treatment results for anal canal carcinoma have reached a satisfactory level. However, patients with larger lesions of the perianal skin are at high risk for locoregional recurrence and possible treatment intensification in this subgroup seems desirable.


International Journal of Colorectal Disease | 2014

The rationale behind complete mesocolic excision (CME) and a central vascular ligation for colon cancer in open and laparoscopic surgery: Proceedings of a consensus conference

Karl Søndenaa; P. Quirke; Werner Hohenberger; Kenichi Sugihara; Hirotoshi Kobayashi; Hermann Kessler; Gina Brown; Tudyka; André D'Hoore; Robin H. Kennedy; Nicholas P. West; Seon Hahn Kim; R. J. Heald; Kristian Eeg Storli; Arild Nesbakken; Brendan Moran

BackgroundIt has been evident for a while that the result after resection for colon cancer may not have been optimal. Several years ago, this was showed by some leading surgeons in the USA but a concept of improving results was not consistently pursued. Later, surgeons in Europe and Japan have increasingly adopted the more radical principle of complete mesocolic excision (CME) as the optimal approach for colon cancer. The concept of CME is a similar philosophy to that of total mesorectal excision for rectal cancer and precise terminology and optimal surgery are key factors.MethodThere are three essential components to CME. The main component involves a dissection between the mesenteric plane and the parietal fascia and removal of the mesentery within a complete envelope of mesenteric fascia and visceral peritoneum that contains all lymph nodes draining the tumour area (Hohenberger et al., Colorectal Disease 11:354–365, 2009; West et al., J Clin Oncol 28:272–278, 2009). The second component is a central vascular tie to completely remove all lymph nodes in the central (vertical) direction. The third component is resection of an adequate length of bowel to remove involved pericolic lymph nodes in the longitudinal direction.ResultThe oncological rationale for CME and various technical aspects of the surgical management will be explored.ConclusionThe consensus conference agreed that there are sound oncological hypotheses for a more radical approach than has been common up to now. However, this may not necessarily apply in early stages of the tumour stage. Laparoscopic resection appears to be equally well suited for resection as open surgery.


Diseases of The Colon & Rectum | 2000

Prospective, blinded comparison of laparoscopic ultrasonography vs. contrast-enhanced computerized tomography for liver assessment in patients undergoing colorectal carcinoma surgery.

Jeffrey W. Milsom; B. L. Jerby; Hermann Kessler; Jonathan Hale; B. R. Herts; Charles M. O'Malley

PURPOSE: To prospectively and blindly compare intraoperative laparoscopic ultrasonography to preoperative contrast-enhanced computerized tomography in detecting liver lesions in colorectal cancer patients. Additionally, we compared conventional (open) intraoperative ultrasonography with bimanual liver palpation to contrast-enhanced computerized tomography in a subset of patients. METHODS: From December 1995 to March 1998, 77 consecutive patients underwent curative (n=63) or palliative (n=14) resections for colorectal cancer. All patients undergoing curative resections were randomized to either laparoscopic (n=34) or conventional (n=29) surgery after informed consent. All patients underwent contrast-enhanced computerized tomography, diagnostic laparoscopy, and laparoscopic ultrasonography before resection. In those patients who had conventional procedures, intraoperative ultrasonography with bimanual liver palpation was also done. All laparoscopic ultrasonography and intraoperative ultrasonography evaluations were performed by one of two radiologists who were blinded to the CT results. All hepatic segments were scanned using a standardized method. The yield of each modality was calculated using the number of lesions identified by each imaging modality divided by the total number of lesions identified. RESULTS: In 43 of the 77 patients, both the laparoscopic ultrasonography and CT scan were negative for any liver lesions. In 34 patients, a total of 130 lesions were detected by laparoscopic ultrasonography, CT, or both. When compared with laparoscopic ultrasonography, intraoperative ultrasonography with bimanual liver palpation identified one additional metastatic lesion and no additional benign lesions. laparoscopic ultrasonography identified two patients with mets who had negative preoperative contrast-enhanced computerized tomography. CONCLUSIONS: Laparoscopic ultrasonography of the liver at the time of primary resection of colorectal cancer yields more lesions than preoperative contrast-enhanced computerized tomography and should be considered for routine use during laparoscopic oncologic colorectal surgery.


Surgical Endoscopy and Other Interventional Techniques | 1999

Successful treatment of rectal prolapse by laparoscopic suture rectopexy

Hermann Kessler; B. L. Jerby; Jeffrey W. Milsom

AbstractBackground: A wide variety of procedures are used for management of rectal prolapse. The purpose of this study was to evaluate the results of laparoscopic suture rectopexy in the treatment of this condition. Methods: From May 1991 to May 1998, 32 consecutive patients were treated by laparoscopic suture rectopexy. In four of them, an additional sigmoid colectomy was performed for refractory constipation or redundant large bowels. The clinical data were analyzed. Results: Of our 32 patients, 27 were female and five were male. The median age was 51.5 years (range, 20–87). The median operative time was 150 min (range, 90–300), and the median hospital stay was 5 days (range, 2–20). There were no operative mortalities. Three postoperative complications required reoperations for bowel obstructions. At a median follow-up of 33 months (range 3–78), there were two complete recurrences. Conclusions: Our experience indicates that laparoscopic suture rectopexy, with and without sigmoid colectomy, is safe, feasible, and effective for the treatment of rectal prolapse.


World Journal of Gastroenterology | 2011

Recent results of laparoscopic surgery in inflammatory bowel disease

Hermann Kessler; Jonas Mudter; Werner Hohenberger

Inflammatory bowel diseases are an ideal indication for the laparoscopic surgical approach as they are basically benign diseases not requiring lymphadenectomy and extended mesenteric excision; well-established surgical procedures are available for the conventional approach. Inflammatory alterations and fragility of the bowel and mesentery, however, may demand a high level of laparoscopic experience. A broad spectrum of operations from the rather easy enterostomy formation for anal Crohns disease (CD) to restorative proctocolectomies for ulcerative colitis (UC) may be managed laparoscopically. The current evidence base for the use of laparoscopic techniques in the surgical therapy of inflammatory bowel diseases is presented. CD limited to the terminal ileum has become a common indication for laparoscopic surgical therapy. In severe anal CD, laparoscopic stoma formation is a standard procedure with low morbidity and short operative time. Studies comparing conventional and laparoscopic bowel resections, have found shorter times to first postoperative bowel movements and shorter hospital stays as well as lower complication rates in favour of the laparoscopic approach. Even complicated cases with previous surgery, abscess formation and enteric fistulas may be operated on laparoscopically with a low morbidity. In UC, restorative proctocolectomy is the standard procedure in elective surgery. The demanding laparoscopic approach is increasingly used, however, mainly in major centers; its feasibility has been proven in various studies. An increased body mass index and acute inflammation of the bowel may be relative contraindications. Short and long-term outcomes like quality of life seem to be equivalent for open and laparoscopic surgery. Multiple studies have proven that the laparoscopic approach to CD and UC is a safe and successful alternative for selected patients. The appropriate selection criteria are still under investigation. Technical considerations are playing an important role for the complexity of both diseases.


Diseases of The Colon & Rectum | 2015

Laparoscopic IPAA is not associated with decreased rates of incisional hernia and small-bowel obstruction when compared with open technique: Long-term follow-up of a case-matched study

Cigdem Benlice; Luca Stocchi; Meagan Costedio; Emre Gorgun; Tracy L. Hull; Hermann Kessler; Feza H. Remzi

BACKGROUND: There are scant data on the presumed reduction of small-bowel obstruction and incisional hernia rates associated with laparoscopic IPAA. OBJECTIVE: The aim of this study was to compare long-term outcomes after open vs laparoscopic IPAA based on a previous study from our institution. DESIGN: This was a retrospective cohort study (from January 1992 through December 2007). SETTINGS: The study was conducted in a high-volume, specialized colorectal surgery department. PATIENTS: Patients included those who were enrolled in a previous institutional case-matched (2:1) study that examined 238 open and 119 laparoscopic IPAAs. MAIN OUTCOME MEASURES: Long-term complications, including incisional hernia clinically detected by physician, adhesive small-bowel obstruction requiring hospital admission and surgery, pouch excision, and pouchitis rates, were collected. Laparoscopic abdominal colectomy followed by rectal dissection under direct vision (lower midline or Pfannenstiel incision) and converted cases were analyzed within the laparoscopic group. RESULTS: Groups were comparable with respect to age, sex, BMI, and extent of resection (completion proctectomy vs proctocolectomy), consistent with the original case matching. Mean follow-up was significantly longer in the open group (9.6 vs 8.1 years; p = 0.008). Open and laparoscopic operations were associated with similar incidences of incisional hernia (8.4% vs 5.9%; p = 0.40), small-bowel obstruction requiring hospital admission (26.1% vs 29.4%; p = 0.50), and small-bowel obstruction requiring surgery (8.4% vs 11.8%; p = 0.31). A subgroup analysis comparing 50 patients with laparoscopic rectal dissection versus 69 patients with rectal dissection under direct vision confirmed statistically similar incidences of incisional hernia, hospital admission, and surgery for small-bowel obstruction. LIMITATIONS: This study was limited by its retrospective nature. CONCLUSIONS: Some of the anticipated long-term benefits of laparoscopic IPAA could not be demonstrated in this cohort. The lack of such long-term benefits should be discussed with patients when proposing a laparoscopic approach.


Diseases of The Colon & Rectum | 2016

Impact of the Specific Extraction-Site Location on the Risk of Incisional Hernia After Laparoscopic Colorectal Resection.

Cigdem Benlice; Luca Stocchi; Meagan Costedio; Emre Gorgun; Hermann Kessler

BACKGROUND: The impact of the specific incision used for specimen extraction during laparoscopic colorectal surgery on incisional hernia rates relative to other contributing factors remains unclear. OBJECTIVE: This study aimed to assess the relationship between extraction-site location and incisional hernia after laparoscopic colorectal surgery. DESIGN: This was a retrospective cohort study (January 2000 through December 2011). SETTINGS: The study was conducted at a high-volume, specialized colorectal surgery department. PATIENTS: All of the patients undergoing elective laparoscopic colorectal resection were identified from our prospectively maintained institutional database. MAIN OUTCOME MEASURES: Extraction-site and port-site incisional hernias clinically detected by physician or detected on CT scan were collected. Converted cases, defined as the use of a midline incision to perform the operation, were kept in the intent-to-treat analysis. Specific extraction-site groups were compared, and other relevant factors associated with incisional hernia rates were also evaluated with univariate and multivariate analyses. RESULTS: A total of 2148 patients (54.0% with abdominal and 46.0% with pelvic operations) with a mean age of 51.7 ± 18.2 years (52% women) were reviewed. Used extraction sites were infraumbilical midline (23.7%), stoma site/right or left lower quadrant (15%), periumbilical midline (22.5%), and Pfannenstiel (29.6%) and midline converted (9.2%). Overall crude extraction site incisional hernia rate during a mean follow-up of 5.9 ± 3.0 years was 7.2% (n = 155). Extraction-site incisional hernia crude rates were highest after periumbilical midline (12.6%) and a midline incision used for conversion to open surgery (12.0%). Independent factors associated with extraction-site incisional hernia were any extraction sites compared with Pfannenstiel (periumbilical midline HR = 12.7; midline converted HR = 13.1; stoma site HR = 28.4; p < 0.001 for each), increased BMI (HR = 1.23; p = 0.002), synchronous port-site hernias (HR = 3.66; p < 0.001), and postoperative superficial surgical-site infection (HR = 2.11; p < 0.001). LIMITATIONS: This study was limited by its retrospective nature, incisional hernia diagnoses based on clinical examination, and heterogeneous surgical population. CONCLUSIONS: Preferential extraction sites to minimize incisional hernia rates should be Pfannenstiel or incisions off the midline. Midline incisions should be avoided when possible.


Annals of Surgery | 2017

Considering Value in Rectal Cancer Surgery: An Analysis of Costs and Outcomes Based on the Open, Laparoscopic, and Robotic Approach for Proctectomy

Jorge Silva-Velazco; David W. Dietz; Luca Stocchi; Meagan Costedio; Emre Gorgun; Matthew F. Kalady; Hermann Kessler; Ian C. Lavery; Feza H. Remzi

Objective: The aim of the study was to compare value (outcomes/costs) of proctectomy in patients with rectal cancer by 3 approaches: open, laparoscopic, and robotic. Background: The role of minimally invasive proctectomy in rectal cancer is controversial. In the era of value-based medicine, costs must be considered along with outcomes. Methods: Primary rectal cancer patients undergoing curative intent proctectomy at our institution between 2010 and 2014 were included. Patients were grouped by approach [open surgery, laparoscopic surgery, and robotic surgery (RS)] on an intent-to-treat basis. Groups were compared by direct costs of hospitalization for the primary resection, 30-day readmissions, and ileostomy closure and for short-term outcomes. Results: A total of 488 patients were evaluated; 327 were men (67%), median age was 59 (27–93) years, and restorative procedures were performed in 333 (68.2%). Groups were similar in demographics, tumor characteristics, and treatment details. Significant outcome differences between groups were found in operative and anesthesia times (longer in the RS group), and in estimated blood loss, intraoperative transfusion, length of stay, and postoperative complications (all higher in the open surgery group). No significant differences were found in short-term oncologic outcomes. Direct cost of the hospitalization for primary resection and total direct cost (including readmission/ileostomy closure hospitalizations) were significantly greater in the RS group. Conclusions: The laparoscopic and open approaches to proctectomy in patients with rectal cancer provide similar value. If robotic proctectomy is to be widely applied in the future, the costs of the procedure must be reduced.

Collaboration


Dive into the Hermann Kessler's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Werner Hohenberger

University of Erlangen-Nuremberg

View shared research outputs
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge