Thermal Damage of the Inner Vein Wall During Endovenous Laser Treatment: Key Role of Energy Absorption by Intravascular Blood

BACKGROUND: Despite the clinical efficacy of endovenous laser treatment (EVLT), its mode of action is incompletely understood. OBJECTIVE: To evaluate the role of intravascular blood for the effective transfer of thermal damage to the vein wall through absorption of laser energy. METHODS: Laser energy (15 J/pulse, 940 nm) was endovenously administered to explanted greater saphenous vein (GSV) segments filled with blood (n = 5) or normal saline (n = 5) in addition to GSVs under in vivo conditions immediately prior to stripping. Histopathology was performed on serial sections to examine specific patterns of damage. Furthermore, in vitro generation of steam bubbles by different diode lasers (810, 940, and 980 nm) was examined in saline, plasma, and hemolytic blood. RESULTS: In saline-filled veins, EVLT-induced vessel wall injury was confined to the site of direct laser impact. In contrast, blood-filled veins exhibited thermal damage in more remote areas including the vein wall opposite to the laser impact. Steam bubbles were generated in hemolytic blood by all three lasers, while no bubbles could be produced in normal saline or plasma. CONCLUSION: Intravascular blood plays a key role for homogeneously distributed thermal damage of the inner vein wall during EVLT.     

Medium-Depth Chemical Peels in the Treatment of Acne Scars in Dark-Skinned Individuals

BACKGROUND: Multiple modalities are available for treating acne scars, one of which is chemical peeling. OBJECTIVE: To evaluate the efficacy of medium-depth peels in the treatment of acne scars. METHODS: A total of 15 patients (14 women and 1 man) were seen between November 1998 and March 2000. A medium-depth chemical peel was performed. The peel was performed using a combination of Jessner's solution followed by the application of 35% trichloroacetic acid (TCA). The mean age of patients who entered the study was 28 years. A total of 42 peeling sessions were performed: 13 patients had the full three-session regiment, 1 patient had two sessions, and 1 had only one session. RESULTS: Patients in our study had two forms of acne scars, the atrophic saucer or crater-like form and the pitted (ice-pick) form. Improvement occurred in all except one of our patients. Significant improvement (greater than 75% clearance of lesions) occurred in 1 patient (6.6%), moderate improvement (51-75% clearance) in 8 patients (53.3%), mild improvement (26-50% clearance) in 4 patients (26.6%), minimal improvement (1-25% clearance) in 1 patient (6.6%), and no response in 1 patient (6.6%). All patients had different combinations of the above two forms. Four patients (26.6%) had mainly pitted scars and deep atrophic scars. The clinical response in those patients was moderate, mild, minimal, and no response, respectively. The remainder of our patients had mainly atrophic scars of moderate depth. Nine patients (73.4%) suffered from transient postinflammatory hyperpigmentation. In two of them it was preceded by erythema that lasted for more than 1 month. All patients were free of noticeable pigmentation 3 months after the final peel. Patients in whom hyperpigmentation did not develop were of light brown complexion. CONCLUSION: We conclude that medium-depth chemical peel is a safe and effective method of treating acne scars even in patients with dark complexion.     

A population-based study of the extent of surgical resection of potentially curable colon cancer

Background We attempted to determine factors contributing to the extent of initial curative resection for colon cancer in a population-based cohort. Total abdominal colectomy with ileorectal anastomosis (TAC-IR) may be considered for young patients or those with a colorectal cancer family history to prevent metachronous lesions and facilitate surveillance. Methods All Ontario patients newly diagnosed with colon cancer over 12 months beginning in July 1997 were staged at the time of surgery. The extent of resection was compared with variables, including familial risk obtained from the Ontario Familial Colon Cancer Registry. Results Complete staging was possible for 86% of patients. A total of 1223 patients had a potentially curative resection: 17%, 46%, and 36% were stage I, II, and III, respectively. Patients were more likely to receive a TAC-IR if they were ≤50 years old (odds ratio [OR], 3.5; 95% confidence interval [CI], 1.8–6.6), if they had a synchronous lesion (OR, 28.37; 95% CI, 12.2–61.2), or if they were at a teaching hospital (OR, 2.8; 95% CI, 1.6–4.7), but not if they had a family history (OR, 7; 95% CI, 3–1.5). Conclusions Young age, teaching hospital, and multiple cancers but not family history were important factors for performing a TAC-IR.     

Predictors of locoregional recurrence among patients with early-stage breast cancer treated with breast-conserving therapy

Background Our aim was to identify predictors of locoregional recurrence (LRR) in patients with early-stage breast cancer treated with breast-conserving therapy (BCT) and long-term follow-up. Methods From 1970 to 1994, 1153 patients with stage I to II breast cancer underwent BCT and radiotherapy at our institution. Patients with prior breast cancer or other primary malignancies were excluded. Clinical and pathologic characteristics evaluated were age, race, tumor size, stage, pathologic tumor margins, axillary nodal involvement, estrogen and progesterone receptor status, Black's nuclear grade, type of surgery, and use of adjuvant therapy. Results Of 1083 patients, 54% presented with stage I disease and 46% with stage II disease. Median age was 50 years, and median follow-up was 9 years. Axillary nodes were positive in 31% of the patients who underwent axillary dissection. LRR developed in 6%, LRR followed by systemic recurrence in 5%, and systemic recurrence alone in 13%, 76% had no evidence of recurrence at last follow-up. Age, tumor size, positive lymph nodes, and not receiving chemotherapy or hormonal therapy were independent predictors of LRR. Disease-specific survival among patients with LRR was similar to that among patients with no recurrence. Conclusions Multidisciplinary treatment strategies should be used to accomplish durable locoregional control after BCT. Presented at the 54th Annual Cancer Symposium of the Society of Surgical Oncology, Washington, DC, March 15–18, 2001.     

Subareolar and peritumoral injection identify similar sentinel nodes for breast cancer

Background Sentinel lymph node (SLN) mapping with radioisotope and blue dye is rapidly becoming the standard of care for breast cancer. The optimal location for injection of radioisotope and blue dye is still being investigated. The goal of this study was to determine whether blue dye injection into the subareolar (SA) location localized the same sentinel nodes as the peritumoral (PT) location for patients with breast cancer. Methods Three hundred thirty-two patients with biopsy-proven operable breast cancer or ductal carcinoma in situ at two institutions underwent SLN mapping. Eighty-three patients had PT injection of blue dye (group 1), and 249 patients had SA injection of blue dye (group 2). All patients underwent PT injection of^99mTc-labeled sulfur colloid. Results The two groups were similar in age, previous biopsy type, and tumor size, location, and histology. The mean number of SLNs identified was 2.4 (range, 0–9) in group 1 and 2.5 (range, 0–11) in group 2. The SLN identification rate was 95% for group 1 and 97% for group 2. The isotope success rate was 94% for both groups. The blue dye success rate was 84% for group 1 and 90% for group 2. The isotope/blue dye concordance rate was 87% for group 1 and 90% for group 2. At a median follow-up of 28 months (range, 14 to 40), there were no axillary recurrences in any of the 332 patients. Conclusions These data suggest that delivery of mapping reagents in the SA and PT locations identifies similar lymph nodes. Because of simplicity and the similarity in node identification between SA and PT injection, further investigation of the SA site for delivery of SLN mapping reagents for breast cancer is warranted. Presented at the 54th Annual Cancer Symposium, Society of Surgical Oncology. Washington, DC, March 15–18, 2001.