Network


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

Hotspot


Dive into the research topics where Joseph Mamazza is active.

Publication


Featured researches published by Joseph Mamazza.


Diseases of The Colon & Rectum | 2001

Defining a learning curve for laparoscopic colorectal resections.

Christopher M. Schlachta; Joseph Mamazza; Pieter A. Seshadri; Margherita Cadeddu; Roger C. Grégoire; Eric C. Poulin

PURPOSE: The purpose of this review was to define the learning curve for laparoscopic colorectal resections. METHODS: A prospectively accumulated, computerized database of all laparoscopic colorectal resections performed by three surgeons between April 1991 and March 1999 was reviewed. RESULTS: A total of 461 consecutive resections were evenly distributed among three surgeons (141, 155, and 165). Median operating time was 180 minutes for Cases 1 to 30 in each surgeons experience and declined to a steady state (150–167.5 minutes) for Cases 31 and higher. Subsequently, Cases 1 to 30 were considered “early experience,” whereas Cases 31 and higher were combined as “late experience” for statistical analysis. There were no significant differences between patients undergoing resections in the early experience and those undergoing resections in the late experience with respect to age, weight, or proportion of patients with malignancy, diverticulitis, or inflammatory bowel disease. There were greater proportions of males (42vs. 54 percent,P=0.046) and rectal resections performed (14vs. 32 percent,P=0.002) in the late experience. Trends toward declining rates of intraoperative complications (9vs. 7 percent,P=0.70) and conversion to open surgery (13.5vs. 9.7 percent,P=0.39) were observed with experience. Median operating time (180vs. 160 minutes,P<0.001) and overall length of postoperative hospital stay (6.5vs. 5 days,P<0.001) declined significantly with experience. There was no difference in the rate of postoperative complications between early and late experience (30vs. 32 percent,P=0.827). CONCLUSIONS: The learning curve for performing colorectal resections was approximately 30 procedures in this study, based on a decline in operating time, intraoperative complications, and conversion rate. Learning was also extended to clinical care because it was appreciated that patients could be discharged to their homes more quickly.


Surgical Endoscopy and Other Interventional Techniques | 2001

Does a laparoscopic approach to total abdominal colectomy and proctocolectomy offer advantages

Pieter A. Seshadri; Eric C. Poulin; Christopher M. Schlachta; Margherita Cadeddu; Joseph Mamazza

BackgroundControversy exists regarding the feasibility, safety, and outcomes of laparoscopic total abdominal colectomy (LTAC) and laparoscopic total proctocolectomy (LTPC). The object of this study was to assess the outcomes of LTAC and LTPC and compare them with those of institutional open procedure used as controls.MethodsPerioperative data and surgical outcomes of patients who underwent TAC or TPC were analyzed and compared retrospectively at a single institution between 1991 and 1999.ResultsA total of 73 TACs performed during a 9-year period were evenly distributed between laparoscopic (n=37) and open (n=36) approaches. There were no significant differences between patient groups with respect to genders, age, weight, proportion of patients with inflammatory bowel disease, and the number of patients undergoing ileorectal anastomosis. The median operative time was longer with the laparoscopic method (270 vs 178 min; p=0.001), but the median length of hospital stay was significantly shorter (6 vs 9 days; p=0.001). The short-term postoperative complication rate up to 30 days from surgery was not statistically different (25% vs 44%; p=0.137), although there was a clear trend toward a reduced number of overall complications in the laparoscopic group (9 vs 24). Wound complications were significantly fewer (0% vs 19%; p=0.015) and postoperative pneumonia was nonexistent in laparoscopic patients. Long-term complications also were less common in the laparoscopic group (20% vs 64%; p=0.002), largely because of reduced incidence of impotence, incisional hernia, and ileostomy complications. Total proctocolectomy was performed laparoscopically in 15 patients and with an open procedure in 13 patients over the same period. There were no statistically significant differences between the two groups with respect to gender, age, weight, and diagnosis. Median operating time was longer for the laparoscopic patients (400 vs 235 min; p=0.001), whereas the length of hospital stay, morbidity, and mortality were not significantly different.ConclusionsThe results indicate that LTAC can be performed safely with a statistically significant reduction in wound and long-term postoperative complications, as compared with its open counterpart. Operating time is increased, but there is a marked reduction in length of hospital stay. Preliminary results demonstrate that LTPC also is technically feasible and safe, with equal morbidity, mortality, and hospital stay, as compared with open procedures. Studies with larger numbers of patients and a randomized controlled trial giving special attention to patient quality-of-life issues are needed to elucidate the real advantages of this minimally invasive technique.


Surgical Endoscopy and Other Interventional Techniques | 1998

Splenic artery embolization before laparoscopic splenectomy An update

Eric C. Poulin; Joseph Mamazza; Christopher M. Schlachta

AbstractBackground: This study assessed preoperative splenic artery embolization before laparoscopic splenectomy. Methods: Preoperative splenic artery embolization was used in 26 of 54 patients (48%) undergoing laparoscopic splenectomy. Between 1992 and 1994, this procedure was used in all patients with spleens shorter than 20 cm (group I), except the first two (18/20). An anterior surgical approach was used. After 1994 (group II), embolization was not used for these patients (0/26), and a lateral surgical approach was used. Throughout the study period, all patients with spleens longer than 20 cm had embolization (8/8). Results: Five complications occurred, three related to the use of small-particle embolic material (microspheres, gelatin foam powder). In group I, the conversion rate was lower than that of most current series, largely because of embolization. In group II, similar results were obtained because of experience and a better surgical approach (i.e., lateral). Conclusions: Preoperative splenic artery embolization is not necessary for spleens shorter than 20 cm. Increased experience and mostly the lateral surgical approach have permitted a shorter operation and a low conversion rate (4%) similar to the rate achieved with embolization and the anterior approach in the initial stages of the study. Embolization is used for 20- to 30-cm spleens. The conversion rate is higher (17%), and blood replacement is required frequently (83%). Despite embolization, laparoscopic splenectomy for spleens longer than 30 cm is futile at this time (100% conversion).


Surgical Endoscopy and Other Interventional Techniques | 2000

Determinants of outcomes in laparoscopic colorectal surgery: a multiple regression analysis of 416 resections.

Christopher M. Schlachta; Joseph Mamazza; Pieter A. Seshadri; Margherita Cadeddu; Eric C. Poulin

AbstractBackground: To date, most large series of laparoscopic colorectal procedures have been descriptive reports that do not account for the potentially complex interaction of outcome predictors. The purpose of this study was to identify the preoperative factors that predict operative time, conversion to open surgery, and intraoperative and postoperative complications in laparoscopic colorectal surgery. Methods: Multiple regression techniques were used to analyze 416 laparoscopic resections from a prospective database of laparoscopic colorectal procedures performed between April 1991 and April 1998. The preoperative factors considered were patient-specific (age, gender, weight) or disease-specific (diagnosis of cancer, Crohns disease, diverticulitis, fistula). Surgical experience of ≤50 cases was also considered. Finally, all resections were represented by a combination of the following five procedure components: resections of the (a) hepatic flexure, (b) splenic flexure, (c) sigmoid, and (d) rectum, or (e) a perineal dissection. Results: Patient weight, Crohns disease, and each of the five individual procedure components incrementally lengthened operative time. Conversion to open surgery was influenced by the patients weight, malignancy, and early experience of the surgeon. The risk of a postoperative complication was increased by the patients age, resection of the perineum, and the presence of a fistula. No factors significantly influenced the risk of an intraoperative complication. Conclusions: Several preoperative factors that significantly affect outcomes in laparoscopic colorectal resections have been identified. Consideration of these factors may help in case selection and estimation of operating time; they should also be valuable when patients are informed of their risk of conversion and complications.


Surgical Endoscopy and Other Interventional Techniques | 2000

Predicting conversion to open surgery in laparoscopic colorectal resections A simple clinical model

Christopher M. Schlachta; Joseph Mamazza; Pieter A. Seshadri; Margherita Cadeddu; Eric C. Poulin

AbstractObjective: The objective of this study was to develop a simple model for clinical use in predicting the individual risk of conversion to open surgery in patients undergoing laparoscopic colorectal resections. Methods: A multiple logistic regression analysis of 367 laparoscopic colorectal resections completed between 1991 and 1998 was performed. The following 13 factors were considered: patient-specific factors (age, gender, weight levels less than 60 kg 60–90 kg, 90 kg or more), disease-specific factors (Crohns disease, diverticulitis, malignancy, fistula), and procedure-specific factors (resection of the hepatic flexure, splenic flexure, sigmoid, rectum, perineum, experience with less than 50 cases). A scoring system was developed on the basis of the three factors found to be predictive of the risk for conversion to open surgery: diagnosis of malignancy (odds ratio 3.23; p= 0.0037; one point), surgeon experience with 50 cases or less (odds ratio 2.26; p= 0.0363; one point), and weight level (odds ratio 3.42; p= 0.005; 60 to 90 kg, one point, 90 kg or more, two points). Results: The predicted conversion rates for the cumulative scores of 0 to 4 points were 1.1%, 3.3%, 9.8%, 25.4%, and 49.7%, respectively. No significant difference was found between predicted and actual conversion rates, indicating a good fit of the model (chi square = 1.774; p > 0.5). Conclusions: This novel scoring system is simple, accurate, and readily applicable in an office setting. It represents the large experience of one surgical group and remains to be validated by other centers.


Surgical Endoscopy and Other Interventional Techniques | 2002

Local recurrence and survival after laparoscopic mesorectal resection for rectal adenocarcinoma

Eric C. Poulin; Christopher M. Schlachta; Roger C. Grégoire; Pieter A. Seshadri; Margherita Cadeddu; Joseph Mamazza

BackgroundLaparoscopic resection for rectal cancer is controversial. Actuarial survival and local recurrence rates have not been determined.MethodsA prospective database containing 80 consecutive unselected laparoscopic resections of rectal cancers performed between November 1991 and 1999 was reviewed. Local recurrence was defined as any detectable local disease at follow-up assessment occurring either alone or in conjunction with generalized recurrence. The tumor node metastases (TNM) classification for colorectal cancers and the Kaplan-Meier method were used to determine staging and survival curves. The mesorectal excision technique was used during surgery.ResultsThe median follow-up period was 31 months for patients with stages, I, II, and III cancer, and 15.5 months for patients with stage IV cancer. The overall 5-year survival rate was 65.1% for all cancer stages and 72.1% for stages I, II, and III cancer. No trocar-site recurrence was observed. The overall local recurrence rate was 3.75% (3/80) for all cancer stages, and 4.3% (3/70) for stages I, II, and III cancer.ConclusionsThe survival and local recurrence rate for patients with rectal cancer treated by laparoscopic mesorectal excision do not differ negatively from those in the literature for open mesorectal excision. Further validation is needed.


Surgical Endoscopy and Other Interventional Techniques | 1999

Laparoscopic splenectomy for hematologic malignancies

Christopher M. Schlachta; Eric C. Poulin; Joseph Mamazza

AbstractBackground: Patients with hematologic malignancy (HM) tend to have large spleens. The purpose of this study was to compare the outcomes of laparoscopic splenectomy for patients with HM to those with benign disease (BD). Methods: A review was conducted of a prospectively accumulated database of 64 consecutive, unselected laparoscopic splenectomies performed by two surgeons between March 1992 and August 1997. Results: Of 14 patients with HM (7 lymphoma, 6 leukemia, 1 myeloid metaplasia), three required conversion to open splenectomy (21%). In the remaining 11 patients, two had postoperation complications (18%), including one death from sepsis (9%). Of 50 patients with BD (36 idiopathic thrombocytopenic purpura [ITP], 5 spherocytosis, 4 hemolytic anemia, and 5 others), three were converted to open surgery (6%). Complications developed in 5 (11%) of the remaining 47 patients. No deaths occurred. All patients who had spleens larger than 27 cm in diameter required conversion. Patients undergoing laparoscopic splenectomy for HM were older (54 ± 16 years vs. 36 ± 18 years; p= 0.002), had larger spleens (median 17.0 cm vs. 11.0 cm; p < 0.001), and had lower preoperation hemoglobin levels (113 ± 30 g/L vs. 132 ± 23 g/L; p= 0.03) than patients with BD. The HM group required longer operation time (239 ± 73 min vs. 180 ± 61 min; p < 0.01), but showed no differences with respect to operation blood loss (median, 100 vs. 165 mL), requirement for transfusion (median, 0.0 vs. 0.0 units), and length of hospital stay (median 3.0 vs. 3.0 days). Conclusions: Although patients with HM had larger spleens and required longer operation time for laparoscopic splenectomy, surgical outcomes were equivalent. The laparoscopic approach should be preferred, even for patients with HM. The only limitation appears to be splenic size greater than 27 cm.


Surgical Endoscopy and Other Interventional Techniques | 2003

Predicting conversion in laparoscopic colorectal surgery Fellowship training may be an advantage

Christopher M. Schlachta; Joseph Mamazza; Roger C. Grégoire; S. E. Burpee; Kenneth T. Pace; Eric C. Poulin

Background: Laparoscopic colorectal surgery has clear advantages over open surgery; however, the effectiveness of the approach depends on the conversion rate. The objective of this work was to prospectively validate a model that would predict conversion in laparoscopic colorectal surgery. Methods: A simple clinical model for predicting conversion in laparoscopic colorectal surgery was previously developed based on a multivariable logistic regression analysis of 367 procedures. This model was applied prospectively to a follow-up group of 248 procedures by the same team, including 54 procedures performed by one new fellowship-trained surgeon. Results: Patients in the follow-up group were more likely to have cancer (56% vs 44%, p = 0.007) and were more obese (median, 71.0 vs 66.0 kg; p < 0.001). The rate of conversion in the follow-up group was unchanged (8.9% vs 9.0%, p > 0.05). Despite expected trends toward increasing risk of conversion with weight level (<60 kg, 6.8%; 60–<90 kg, 9.0%; >90 kg, 12.1%; p > 0.05) and malignancy (10.1% vs 7.3%, p > 0.05), the model did not distinguish well between groups at risk for conversion. Contrary to the model, however, the fellowship-trained surgeon had a conversion rate that was not higher than that of the other, more experienced surgeons (7.3% vs 9.3%, p > 0.05) even though he was less experienced, and operating on patients who were more obese (median, 75.0 vs 70 kg; p = 0.02) and more likely to have cancer (59% vs 55%, p > 0.05). Recalculated conversion scores that excluded the inexperience point for the fellowship-trained surgeon showed a good fit for the model. Considering the original and follow-up experience together (615 cases), the model clearly stratifies patients into low (0 points), medium (1–2 points), and high risk (3–4 points) for conversion, with respective rates of 2.9%, 8.1%, and 20% (p = 0.001). Conclusion: This model appears to be a valid predictor of conversion to open surgery. Fellowship training may provide sufficient experience so that learning curve issues are redundant in early practice. This model now requires validation by other centers.


Surgical Endoscopy and Other Interventional Techniques | 2003

Health-related quality of life after laparoscopic and open nephrectomy.

Kenneth T. Pace; Sarah Dyer; R.J. Stewart; R.J.D.A. Honey; Eric C. Poulin; Christopher M. Schlachta; Joseph Mamazza

Background: Postoperative recovery often is assessed with parameters (pain and return to work) susceptible to bias. This study sought objectively to compare postoperative health-related quality of life (HRQL) after laparoscopic and open nephrectomy with the Postoperative Recovery (PRS) (a validated questionnaire designed to assess pain), activities of daily living (ADL), and HRQL in postoperative patients. Methods: Patients undergoing contemporaneous laparoscopic and open nephrectomy received the PRS pre- and postoperatively. The results were analyzed with analysis of covariance (ANCOV) and survival analysis. Results: The 33 open nephrectomy and 38 laparoscopic patients in this study were comparable in age, gender, body mass index (BMI) and employment. Laparoscopic operative time was longer (p = 0.015), and the hospital stay was shorter (p<0.001). Laparoscopic patients had higher HRQL scores from postoperative days 3 to 365 (p<0.001), and they returned to preoperative HRQL faster (p<0.001). Conclusions: An objective HRQL instrument confirms that laparoscopic nephrectomy patients recover faster and with a higher HRQL than open surgery patients. The PRS can be modified for use after other abdominal procedures, and may prove useful for comparisons of other minimally invasive surgical techniques.


Surgical Endoscopy and Other Interventional Techniques | 1999

Laparoscopic sigmoid resection for acute and chronic diverticulitis. An outcomes comparison with laparoscopic resection for nondiverticular disease.

Christopher M. Schlachta; Joseph Mamazza; Eric C. Poulin

AbstractBackground: Sigmoid diverticulitis is a common benign condition; however, cases of acute and chronic diverticulitis may be difficult for the surgeon to treat. We designed a study to compare the outcomes of patients who undergo laparoscopic resections for sigmoid diverticulitis with those who have similar resections for other indications. Methods: From a prospectively accumulated database of 397 consecutive laparoscopic colorectal procedures performed by three surgeons, we reviewed the outcomes of 178 patients who underwent laparoscopic sigmoid resections with primary anastomosis. Results: Laparoscopic sigmoid colectomies or anterior resections were performed in 22 patients with acute diverticulitis (AD), 70 patients with chronic diverticulitis (CD), and 86 patients with nondiverticular disease (ND). Patients with ND were significantly older than those with AD or CD (67 ± 14 year versus 55 ± 13 year, 55 ± 12 year, p < 0.05). Conversion to open surgery was required in three AD patients (14%), three CD patients (4%), and 17 ND patients (20%) (χ2= 8.23, p= 0.016). In cases completed laparoscopically, there was no significant difference in median operative time (AD, 165 min; CD, 150 min; ND, 165 min), proportion of patients with intraoperative complications (AD, one; CD, six; ND, one), or postoperative complications (AD, four; CD, 13; ND, 11). The occurrence of a postoperative complication significantly prolonged median time to full diet (4 days vs 3 days, p < 0.001) and discharge (9 days vs 5 days, p < 0.001) but not return to normal activity (16 days vs 15 days). Conclusions: In this study, patients who underwent laparoscopic sigmoid colectomies and anterior resections had similar outcomes regardless of diagnosis. This finding substantiates our view that laparoscopic resections for diverticulitis can be performed safely and with the same benefits as resections for other indications.

Collaboration


Dive into the Joseph Mamazza'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
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge