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P Christos

Publications and source records attributed to P Christos.

7 recordsLinked to original sources
PubMed2004

Construct validity for the LAPSIM laparoscopic surgical simulator.

BACKGROUND: The skills required for laparoscopic surgery are amenable to simulator-based training. Several computerized devices are now available. We hypothesized that the LAPSIM simulator can be shown to distinguish novice from experienced laparoscopic surgeons, thus establishing construct validity. METHODS: We tested residents of all levels and attending laparoscopic surgeons. The subjects were tested on eight software modules. Pass/fail (P/F), time (T), maximum level achieved (MLA), tissue damage (TD), motion, and error scores were compared using the t-test and analysis of variance. RESULTS: A total of 54 subjects were tested. The most significant difference was found when we compared the most (seven attending surgeons) and least experienced (10 interns) subjects. Grasping showed significance at P/F and MLA (p < 0.03). Clip applying was significant for P/F, MLA, motion, and errors (p < 0.02). Laparoscopic suturing was significant for P/F, MLA, T, TD, as was knot error (p < 0.05). This finding held for novice, intermediate, and expert subjects (p < 0.05) and for suturing time between attending surgeons and residents (postgraduate year [PGY] 1-4) (p < 0.05). CONCLUSIONS: LAPSIM has construct validity to distinguish between expert and novice laparoscopists. Suture simulation can be used to discriminate between individuals at different levels of residency and expert surgeons.

Clinical Competence↗
PubMed2004

Factors associated with residual breast cancer after re-excision for close or positive margins.

BACKGROUND: Successful breast conservation surgery (BCS) requires complete tumor excision. Margin status of the initial specimen determines the need for additional surgery. We explored factors associated with residual cancer (RC) upon follow-up surgery in patients with close, positive, or undetermined margins following BCS. METHODS: A retrospective analysis of 276 patients with initial close, positive, or undetermined margins who underwent re-excision (RE) or mastectomy was conducted. All initial excisions were intended as definitive procedures. Chi-square analysis was used to identify factors that may predict RC. RESULTS: Of 276 patients, 87 had close, 168 had positive, and 21 had undetermined margins on initial excision. Of this group, 63% (175/276) had RC upon RE or mastectomy. Of positive-margin patients, 68% had RC, compared with 53% of close-margin and 67% of undetermined-margin patients (P = .006). Tumors >/=2 cm were more often associated with RC than smaller tumors (70.8% vs. 56.5%; P = .07). This association was strongest in positive-margin patients (P = .04). High tumor grade was associated with RC in all groups. RC linearly increased with the number of involved margins (P = .02). Specimen inking with multiple colors was associated with decreased risk of RC (P = .004). CONCLUSIONS: Over half of patients with involved or undetermined margins had RC upon RE or mastectomy. Positive and undetermined margins were more often associated with RC than close margins. Larger tumor size was associated with RC in patients with positive. Increasing tumor grade suggests a greater chance of detecting RC in all groups. Multiple involved margins led to a greater risk of RC.

Adult↗
PubMed2004

Breast cancer in patients with residual invasive carcinoma is more accurately staged with additive tumor size assessment.

BACKGROUND: Accurate assessment of tumor size for patients with breast cancer undergoing re-excision following breast-conserving therapy is important for appropriate staging and adjuvant treatment. We investigated the accuracy of additive vs. nonadditive size assessment in determining final tumor stage. METHODS: Patients with infiltrating carcinoma in the initial excision and in at least one additional re-excision (re-excision positive; n = 89) had tumor size assessed with additive and nonadditive techniques. This group was compared with patients undergoing re-excision but without identifiable residual carcinoma (re-excision negative; n = 105) regarding rates of lymph node (LN) metastasis. RESULTS: The re-excision positive patients had a different median final tumor size depending on the size assessment technique used (nonadditive: 1.8 cm; additive: 3.0 cm; P <.0001). Both groups of patients had a median tumor size consistent with T1c staging in nonadditive size assessment. However, re-excision positive patients had a significantly higher incidence of LN metastasis (P <.05) than did re-excision negative patients. Both groups were then separated into T1 and T2 stages and the LN metastasis rates were assessed. Compared with nonadditive size assessment, additive size assessment distributed re-excision positive patients into T stages whereby the LN metastasis rates more closely approximated those of re-excision negative patients (T1, 3% vs. 6% difference; T2, 4% vs. 13% difference). CONCLUSIONS: With regard to LN metastasis, staging for patients with residual invasive carcinoma in re-excision specimens is more accurate with additive tumor size assessment.

Breast Neoplasms↗
PubMed2001

Recurrence rates in patients with central or retroareolar breast cancers treated with mastectomy or lumpectomy.

BACKGROUND: Although breast conservation with lumpectomy and radiation treatment has become a commonly used treatment for breast cancer, there are little data to support the use of lumpectomy for central and retroareolar breast cancers. In this study, we investigate the local and distant recurrence rates of patients with central or retroareolar breast cancers treated with lumpectomy compared with mastectomy. METHODS: This study provides a retrospective analysis of 99 patients, from 1981 to 2000, with central or retroareolar breast cancers treated with mastectomy or lumpectomy to determine the frequency of local and distant recurrence. The mastectomy and lumpectomy patients were compared with respect to recurrence and other prognostic factors including: tumor location, tumor size, axillary nodal status, and final surgical margins. RESULTS: The overall frequency of local recurrence was 5 of 99 (5.0%) in the entire group, 3 of 67 (4.5%) and 2 of 32 (6.3%) of patients who underwent mastectomy and lumpectomy, respectively (P >0.99). Overall, 3 patients experienced a distant recurrence as a first event, with 2 patients (3.0%) in the mastectomy group and 1 patient (3.1%) in the lumpectomy group (P >0.99). The type of surgical management was not statistically significant related to either local or distant disease recurrence, with median time to local recurrence of 3.0 years for the mastectomy patients and 5.0 years for lumpectomy patients. Of the patients with central tumors who underwent mastectomy 2 of 42 (4.8%) developed local recurrences compared with those who had a lumpectomy, 1 of 21 (4.8%). Similarly for retroareolar tumors, the local recurrence rate was 1 of 25 (4.0%) for patients undergoing mastectomy and 1 of 11 (9.1%) for those undergoing lumpectomy (P >0.99). CONCLUSIONS: In this study there was no significant difference in local or distant failure rates of those patients with central or retroareolar tumors treated with mastectomy versus lumpectomy. We conclude lumpectomy to be a reasonable treatment option for selected patients with central or retroareolar breast cancers.

Adult↗
PubMedDate not supplied

Local and distant recurrence rates in skin-sparing mastectomies compared with non-skin-sparing mastectomies.

BACKGROUND: Skin-sparing mastectomies (SSMs) are being used more frequently to treat many cases of breast cancer. This type of surgery maximizes breast skin preservation and facilitates immediate reconstruction, resulting in a superior cosmetic appearance after mastectomy and a more satisfied patient. Although SSMs are becoming more common, there are few data regarding the local and distant recurrence rates. METHODS: A total of 231 patients treated with mastectomies from 1990 to 1998 were studied, including 77 SSM and 154 non-skin-sparing (NSSM) mastectomy patients. RESULTS: The local recurrence rates for SSM and NSSM were 3.90% (3 of 77 patients) and 3.25% (5 of 154 patients), respectively. The local recurrence-free survival at 5 years was 95.3% for SSM patients and 95.2% for NSSM patients (P = .28). The distant recurrence rates of SSM and NSSM were 3.9% (3 of 77 patients) and 3.9% (6 of 154 patients), respectively. The distant recurrence-free actuarial survival at 5 years was 90.2% for SSM patients and 92% for NSSM patients (P = .07). CONCLUSIONS: Mastectomies using the skin-sparing technique do not appear to result in any increase in local or distant recurrence and improve aesthetic results of the immediate reconstruction.

Adult↗