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The Nuss procedure: Initial results with 27 patients
directly to surgery, which included ALND. Axillary nodal status after surgery was compared with preoperative status. Setting: A multidisciplinary breast center. Patients or Other Participants: Eighteen patients (median age, 46 years; range, 31 to 77 years) with LABC. Interventions: Ultrasound-guided FNAB of suspicious lymph nodes followed by ALND. Main Outcome Measures: Clinical examination of the axilla, ultrasoundguided FNAB, and final pathology of ALND were compared. Results: Axillary Examination
Number
US/FNAB (ⴙ)
US/FNAB (ⴚ)
ALND (ⴙ)
ALND (ⴚ)
Clinical (⫹) Clinical (⫺)
13 6
11 5
2 1
13 5
0 1
Conclusions: In patients with LABC, axillary ultrasound, followed by FNAB of suspicious nodes can accurately stage the axilla. This is particularly useful for patients with clinically negative axillae for whom NAC is a consideration. 12 The Nuss procedure: initial results with 27 patients Tashjian DB, Moriarty KP, Banever G, Konefal SH Jr. From the Division of Pediatric Surgery, Baystate Medical Center Children’s Hospital and Shriners Children’s Hospital, Tufts University School of Medicine, Springfield, Massachusetts. Purpose: The “gold standard” repair for pectus excavatum is the technique originally described by Ravitch. The Nuss procedure, a minimally invasive pectus excavatum repair without cartilage resection or sternal osteomy, was first described in 42 patients in 1998. This technique has gained rapid acceptance. We present our results from the initial 27 patients undergoing the minimally invasive Nuss pectus repair. Methods: A retrospective review of patients undergoing the Nuss procedure from April 1998 until the present was performed. Data concerning age, sex, clinical symptoms, computed tomography scan evaluation, operative time, length of hospital stay, and complications were recorded. Results from patients whose bar has been removed were also retrieved. Results: Twenty-seven patients, 21 males and 6 females, underwent the Nuss procedure. The average age of the patients was 12.4 years, with a range of 4 to 18 years. Preoperative symptoms included asthma, exercise intolerance, chest pain, or no symptoms. Average operative time was 86.7 minutes. Blood loss was minimal in each case. The average length of hospital stay was 6 days. Six immediate postoperative pneumothoracies occurred, none requiring a thoracostomy tube. Two bars became displaced. One occurred at 1 month, which was replaced, and the other at 15 months, which was removed. Only 1 patient had infection necessitating bar removal. Two bar stabilizers needed to be replaced. A total of 5 bars have been removed, all with excellent patient satisfaction. Conclusions: Compared with the open repair, the Nuss procedure offers decreased operative times, minimal blood loss, and improved cosmesis. Patient satisfaction is excellent. Long-term follow-up is needed. Based on short-term results, the minimally invasive Nuss procedure is a safe and effective alternative to the open pectus repair. 13 Tissue-engineered colon: characterization and comparison to native colon Grikscheit TC,* Ochoa ER,† Ramsanahie A,‡ Whang EE,‡ Vacanti JP.* From the Departments of *Surgery and †Pathology, Massachusetts General Hospital, and the ‡Department of Surgery, Brigham and Women’s Hospital. Boston, Massachusetts. Purpose: Postcolectomy morbidity rates from 5% to 30% have been reported. We created a tissue-engineered colon (TEC) substitute for surgical therapy using biodegradable polymer constructs to transplant multicellular sigmoid organoid units (OU). Characterization of TEC reveals significant similarity to 560
native colon (NC). For the first time, engineered intestine was constructed from adult rats and TEC. Methods: Organoid units were harvested from 6-day-old Lewis rats by excision, dissociation, differential centrifugation, and enzyme digestion, then seeded on 2-mm nonwoven polyglycolic acid/polylactic acid porous felt 1-cm ⫻ 0.5-cm tubular constructs, and implanted in 20 male Lewis rat omentums. At 4 weeks, 10 rats underwent ileo-colic or colo-colic anastomosis. Histology on TEC and anastomosed TEC included PAS, trichrome, and anti¨ ssing acetylcholinesterase (ACh). TEM and TUNEL assay were performed. U chamber studies assessed epithelial transport. Organoid units from 4-monthold adult Lewis rats were likewise implanted and studied. Results: All rats generated TEC at 4 weeks with uniform colonic epithelium, crypts of Lieberkuhn, and goblet cells. An outer longitudinal layer resembled a smooth muscle. After anastomosis, colon morphology was preserved for the study’s length, 6 weeks. As in NC, ACh stained the lamina propria; PAS stain revealed typical goblet cells, and Trichrome staining revealed a blue collagenrich submucosa. TEM revealed an exact repetition of NC architecture, including tight junctions, desmosomes with keratin filaments, neuroendocrine cells, and apical microvilli with anchoring filaments. TUNEL assays were equivalent ¨ ssing chamber studies exhibited a spontaneous short-circuit in NC and TEC. U current, suggesting active ion transport, and no short-circuit current response to 3-O-methylglucose addition, suggesting absence of epithelial SGLT1 expression, consistent with the presence of mature colonocytes. Positive short-circuit current response to theophylline suggests intact secretagogue-induced chloride secretion and tissue viability. Conclusions: A tissue-engineered colon is similar to NC by histology and preliminary functional assessment. This is the first report of engineered tissue derived from engineered tissue or adult intestine. Colon morphology in anastomosis confirms the source of TEC. A tissue-engineered colon may help provide a replacement function for postcolectomy patients in the future. 14 Tissue-engineered small intestine: ontogeny of the immune system Perez A,* Blumberg RS,† Grikscheit TC,‡ Ashley SW,* Vacanti JP,‡ Whang EE.* From the *Department of Surgery and †Division of Gastroenterology, Brigham and Women’s Hospital, and the ‡Department of Surgery, Massachusetts General Hospital. Boston, Massachusetts. Purpose: We have tissue-engineered neointestine that regenerates structural and transporter properties of native jejunum. Before our neointestine can undergo clinical application, mucosal immune function would need to be demonstrated. We hypothesized that the neointestinal mucosa is capable of developing a mature immune system and that exposure to luminal antigenic stimuli is critical to this development. Methods: Neointestinal cysts were engineered by implanting polymer-organoid constructs into adult rats. Neointestine (NA: cysts left nonanastomosed, n ⫽ 6 and AN: cysts anastomosed to native bowel, n ⫽ 4) and native jejunum were harvested serially (3 to 56 weeks postoperatively). Immune cell subsets were characterized by immunohistochemical detection of cell-specific antigens [T cells (CD 3), B cells (CD 32), NK cells (CD 56), and macrophages (CD 68)] combined with computer-based morphometry. Results: Neomucosal immune cell population was a function of exposure to luminal antigens and time of harvest. In AN mucosa harvested at 20 weeks, the density and topographical distribution of immune cell subsets was identical to that of normal jejunum. Table. Mucosal Immune Cell Density (cells/m2, mean ⴞ S.D.) CD
NA (20 weeks)
AN (10 weeks)
AN (20 weeks)
CD 3 CD 32
0.7 ⫻ 104 ⫾ 0.8 ⫻ 104* 0*
CD 56
0*
0.9 ⫻ 104 ⫾ 0.2 ⫻ 104** 0.2 ⫻ 104 ⫾ 0.1 ⫻ 104** 0**
CD 68
0*
0**
1.7 ⫻ 104 ⫾ 0.5 ⫻ 104 1.5 ⫻ 104 ⫾ 0.5 ⫻ 104 1.0 ⫻ 104 ⫾ 0.3 ⫻ 104 0.2 ⫻ 104 ⫾ 0.1 ⫻ 104
Jejunum 1.1 ⫻ 104 ⫾ 0.6 ⫻ 104 1.3 ⫻ 104 ⫾ 0.3 ⫻ 104 0.7 ⫻ 104 ⫾ 0.1 ⫻ 104 0.3 ⫻ 104 ⫾ 0.1 ⫻ 104
* p ⬍ 0.05 vs AN20 and Jej, ** p ⬍ 0.05 vs AN20. ANOVA with Tukey HSD.
CURRENT SURGERY • Volume 58/Number 6 • November/December 2001
Number
US/FNAB (ⴙ)
US/FNAB (ⴚ)
ALND (ⴙ)
ALND (ⴚ)
Clinical (⫹) Clinical (⫺)
13 6
11 5
2 1
13 5
0 1
Conclusions: In patients with LABC, axillary ultrasound, followed by FNAB of suspicious nodes can accurately stage the axilla. This is particularly useful for patients with clinically negative axillae for whom NAC is a consideration. 12 The Nuss procedure: initial results with 27 patients Tashjian DB, Moriarty KP, Banever G, Konefal SH Jr. From the Division of Pediatric Surgery, Baystate Medical Center Children’s Hospital and Shriners Children’s Hospital, Tufts University School of Medicine, Springfield, Massachusetts. Purpose: The “gold standard” repair for pectus excavatum is the technique originally described by Ravitch. The Nuss procedure, a minimally invasive pectus excavatum repair without cartilage resection or sternal osteomy, was first described in 42 patients in 1998. This technique has gained rapid acceptance. We present our results from the initial 27 patients undergoing the minimally invasive Nuss pectus repair. Methods: A retrospective review of patients undergoing the Nuss procedure from April 1998 until the present was performed. Data concerning age, sex, clinical symptoms, computed tomography scan evaluation, operative time, length of hospital stay, and complications were recorded. Results from patients whose bar has been removed were also retrieved. Results: Twenty-seven patients, 21 males and 6 females, underwent the Nuss procedure. The average age of the patients was 12.4 years, with a range of 4 to 18 years. Preoperative symptoms included asthma, exercise intolerance, chest pain, or no symptoms. Average operative time was 86.7 minutes. Blood loss was minimal in each case. The average length of hospital stay was 6 days. Six immediate postoperative pneumothoracies occurred, none requiring a thoracostomy tube. Two bars became displaced. One occurred at 1 month, which was replaced, and the other at 15 months, which was removed. Only 1 patient had infection necessitating bar removal. Two bar stabilizers needed to be replaced. A total of 5 bars have been removed, all with excellent patient satisfaction. Conclusions: Compared with the open repair, the Nuss procedure offers decreased operative times, minimal blood loss, and improved cosmesis. Patient satisfaction is excellent. Long-term follow-up is needed. Based on short-term results, the minimally invasive Nuss procedure is a safe and effective alternative to the open pectus repair. 13 Tissue-engineered colon: characterization and comparison to native colon Grikscheit TC,* Ochoa ER,† Ramsanahie A,‡ Whang EE,‡ Vacanti JP.* From the Departments of *Surgery and †Pathology, Massachusetts General Hospital, and the ‡Department of Surgery, Brigham and Women’s Hospital. Boston, Massachusetts. Purpose: Postcolectomy morbidity rates from 5% to 30% have been reported. We created a tissue-engineered colon (TEC) substitute for surgical therapy using biodegradable polymer constructs to transplant multicellular sigmoid organoid units (OU). Characterization of TEC reveals significant similarity to 560
native colon (NC). For the first time, engineered intestine was constructed from adult rats and TEC. Methods: Organoid units were harvested from 6-day-old Lewis rats by excision, dissociation, differential centrifugation, and enzyme digestion, then seeded on 2-mm nonwoven polyglycolic acid/polylactic acid porous felt 1-cm ⫻ 0.5-cm tubular constructs, and implanted in 20 male Lewis rat omentums. At 4 weeks, 10 rats underwent ileo-colic or colo-colic anastomosis. Histology on TEC and anastomosed TEC included PAS, trichrome, and anti¨ ssing acetylcholinesterase (ACh). TEM and TUNEL assay were performed. U chamber studies assessed epithelial transport. Organoid units from 4-monthold adult Lewis rats were likewise implanted and studied. Results: All rats generated TEC at 4 weeks with uniform colonic epithelium, crypts of Lieberkuhn, and goblet cells. An outer longitudinal layer resembled a smooth muscle. After anastomosis, colon morphology was preserved for the study’s length, 6 weeks. As in NC, ACh stained the lamina propria; PAS stain revealed typical goblet cells, and Trichrome staining revealed a blue collagenrich submucosa. TEM revealed an exact repetition of NC architecture, including tight junctions, desmosomes with keratin filaments, neuroendocrine cells, and apical microvilli with anchoring filaments. TUNEL assays were equivalent ¨ ssing chamber studies exhibited a spontaneous short-circuit in NC and TEC. U current, suggesting active ion transport, and no short-circuit current response to 3-O-methylglucose addition, suggesting absence of epithelial SGLT1 expression, consistent with the presence of mature colonocytes. Positive short-circuit current response to theophylline suggests intact secretagogue-induced chloride secretion and tissue viability. Conclusions: A tissue-engineered colon is similar to NC by histology and preliminary functional assessment. This is the first report of engineered tissue derived from engineered tissue or adult intestine. Colon morphology in anastomosis confirms the source of TEC. A tissue-engineered colon may help provide a replacement function for postcolectomy patients in the future. 14 Tissue-engineered small intestine: ontogeny of the immune system Perez A,* Blumberg RS,† Grikscheit TC,‡ Ashley SW,* Vacanti JP,‡ Whang EE.* From the *Department of Surgery and †Division of Gastroenterology, Brigham and Women’s Hospital, and the ‡Department of Surgery, Massachusetts General Hospital. Boston, Massachusetts. Purpose: We have tissue-engineered neointestine that regenerates structural and transporter properties of native jejunum. Before our neointestine can undergo clinical application, mucosal immune function would need to be demonstrated. We hypothesized that the neointestinal mucosa is capable of developing a mature immune system and that exposure to luminal antigenic stimuli is critical to this development. Methods: Neointestinal cysts were engineered by implanting polymer-organoid constructs into adult rats. Neointestine (NA: cysts left nonanastomosed, n ⫽ 6 and AN: cysts anastomosed to native bowel, n ⫽ 4) and native jejunum were harvested serially (3 to 56 weeks postoperatively). Immune cell subsets were characterized by immunohistochemical detection of cell-specific antigens [T cells (CD 3), B cells (CD 32), NK cells (CD 56), and macrophages (CD 68)] combined with computer-based morphometry. Results: Neomucosal immune cell population was a function of exposure to luminal antigens and time of harvest. In AN mucosa harvested at 20 weeks, the density and topographical distribution of immune cell subsets was identical to that of normal jejunum. Table. Mucosal Immune Cell Density (cells/m2, mean ⴞ S.D.) CD
NA (20 weeks)
AN (10 weeks)
AN (20 weeks)
CD 3 CD 32
0.7 ⫻ 104 ⫾ 0.8 ⫻ 104* 0*
CD 56
0*
0.9 ⫻ 104 ⫾ 0.2 ⫻ 104** 0.2 ⫻ 104 ⫾ 0.1 ⫻ 104** 0**
CD 68
0*
0**
1.7 ⫻ 104 ⫾ 0.5 ⫻ 104 1.5 ⫻ 104 ⫾ 0.5 ⫻ 104 1.0 ⫻ 104 ⫾ 0.3 ⫻ 104 0.2 ⫻ 104 ⫾ 0.1 ⫻ 104
Jejunum 1.1 ⫻ 104 ⫾ 0.6 ⫻ 104 1.3 ⫻ 104 ⫾ 0.3 ⫻ 104 0.7 ⫻ 104 ⫾ 0.1 ⫻ 104 0.3 ⫻ 104 ⫾ 0.1 ⫻ 104
* p ⬍ 0.05 vs AN20 and Jej, ** p ⬍ 0.05 vs AN20. ANOVA with Tukey HSD.
CURRENT SURGERY • Volume 58/Number 6 • November/December 2001