Biomedical subjects

B W Feig

Publications and source records attributed to B W Feig.

50 records · Page 3Linked to original sources

PubMed1997

The safety of helium for abdominal insufflation.

BACKGROUND: A search for alternative methods of abdominal insufflation has been prompted by the fact that CO2 insufflation may cause acidosis, decreased cardiac output, increased systemic vascular resistance, and increased cardiac filling pressures. This study evaluates the safety and the cardiopulmonary effects of helium abdominal insufflation (HAI). METHODS: Thirteen ASA class III and IV patients undergoing laparoscopic procedures were studied in a prospective, nonrandomized protocol using HAI. Cardiopulmonary parameters were measured before and after anesthetic induction and every 30 min during HAI. Abdominal insufflation pressure was initially 10 mmHg and was increased to 15 mmHg after 30 min. All measurements were repeated 15 min after deflation of the abdomen. Changes were evaluated by ANOVA. RESULTS: No significant cardiopulmonary complications were observed. No patient developed hypercarbia or acidosis. Peak inspiratory pressure increased with HAI from 20 +/- 1 to 34 +/- 2 cm H2O (p < 0.0001). Cardiac index decreased (3.35 +/- 0.19 vs 2.37 +/- 0.19 l/min/m2; p = 0.0303) and systemic vascular resistance increased (1,123 +/- 66 vs 1,406 +/- 126 dyne . s/cm5; p = 0.0512) while cardiac filling pressures increased with insufflation to 15 mmHg. CONCLUSIONS: Minimal cardiac and pulmonary aberrations were observed. Helium was safe for abdominal insufflation and may be the insufflating agent of choice in patients with significant cardiopulmonary disease.

Adult↗

PubMed1997

Gallbladder cancer and trocar site recurrences.

BACKGROUND: Critics of laparoscopic surgery cite an increased incidence of tumor recurrence at the trocar sites following laparoscopic cholecystectomy in patients incidentally found to have carcinoma of the gallbladder. The purpose of this review was to determine if laparoscopic cholecystectomy performed in patients with gallbladder cancer results in an increased incidence of abdominal wall recurrences. METHODS: The charts of all patients with gallbladder cancer registered at the University of Texas M. D. Anderson Cancer Center from January 1991 through April 1996 were retrospectively reviewed. Data were collected on initial and subsequent surgical procedures, tumor grade and histology, T stage, adjuvant therapy, and survival. These data were analyzed with regard to abdominal wall recurrences and outcome. RESULTS: Ninety-three patients with gallbladder cancer were seen during this period; 79 patients with complete follow-up information comprised the study population. Comparison of the incidence of abdominal wall recurrences among the categories of surgical procedure (laparoscopic versus open versus laparoscopic converted to open) did not reveal any statistically significant differences. Overall 5-year survival was 10%. CONCLUSIONS: Gallbladder cancer is an aggressive malignancy with few long-term survivors. In addition, these data show that the incidence of abdominal wall implantation is not increased with laparoscopic surgery but is more likely a manifestation of the aggressive nature of this tumor.

Abdominal Muscles↗

PubMed1997

Preoperative chemotherapy for stage IIIB extremity soft tissue sarcoma: long-term results from a single institution.

PURPOSE: To review a single institution's long-term results with doxorubicin-based preoperative chemotherapy for American Joint Committee on Cancer (AJCC) stage IIIB extremity soft tissue sarcoma (STS). PATIENTS AND METHODS: The records of all patients with AJCC stage IIIB extremity STS treated with preoperative chemotherapy between 1986 and 1990 at The University of Texas M.D. Anderson Cancer Center were reviewed to assess rates of response, local recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival (OS). RESULTS: Seventy-six patients with stage IIIB disease received preoperative chemotherapy. The median sarcoma size was 10 cm. Seventy-two patients (95%) had tumors located deep to the muscular fascia. Most patients received a median of three preoperative cycles of doxorubicin and dacarbazine (ADIC), cyclophosphamide and ADIC (CyADIC), or other doxorubicin-based regimens. Radiographic response rates were as follows: complete response (CR), 9%; partial response (PR), 19%; minor response, 13%; stable disease, 30%; and progression, 30%. The overall objective major response rate (CRs plus PRs) was 27%. At a median follow-up time of 85 months, 5-year actuarial rates of LRFS, DMFS, DFS, and OS with 95% confidence intervals (CIs) were 83% (CI, 73% to 94%), 52% (CI, 41% to 66%), 46% (CI, 35% to 60%), and 59% (CI, 48% to 72%), respectively. Comparison of responding patients (CRs plus PRs) and nonresponding patients did not show any significant differences in LRFS, DMFS, DFS, or OS. CONCLUSION: Preoperative doxorubicin-based chemotherapy was associated with response, DFS, and OS rates similar to those observed in randomized postoperative chemotherapy trials. Responding patients had rates of LRFS, DMFS, DFS, and OS comparable to those of nonresponders.

Adolescent↗

PubMed1996

Alternative methods of exposure minimize cardiopulmonary risk in experimental animals during minimally invasive surgery.

BACKGROUND: Alternative methods of exposure are needed for minimally invasive surgery to avoid hypercarbia and acidosis associated with carbon dioxide (CO2) abdominal insufflation. The goals of this study were to determine the pulmonary and hemodynamic effects of both helium (HE) abdominal insufflation and placement of a mechanical abdominal wall-lifting device (lifter) during laparoscopy. METHODS: Sixteen adult domestic pigs under general endotracheal anesthesia underwent baseline measurements of pulmonary capillary wedge pressure (PCWP), cardiac output (CO), and arterial blood gas. Six pigs underwent standard CO2 abdominal insufflation, five pigs underwent abdominal insufflation with HE, and a lifter was used for exposure in five other animals. Sequential readings of PCWP, CO, and arterial blood gas were recorded at 20-min intervals for 60 min in all 16 animals. RESULTS: No significant changes from baseline values were noted in arterial pCO2 or pH in animals who underwent placement of the lifter at any time point. After undergoing HE insufflation, animals experienced modest but significant acidosis and little change in pCO2. There was a significant rise in arterial pCO2 and decrease in pH from baseline values at all time points in animals undergoing CO2 insufflation. CONCLUSIONS: This study shows that neither HE abdominal insufflation or the lifter have significant deleterious pulmonary or hemodynamic effects on experimental animals during laparoscopy. Gasless laparoscopy or HE insufflation may provide a safer alternative method of exposure for minimally invasive surgery in patients with pre-existing pulmonary or cardiac dysfunction. By minimizing risk in these patients, costly invasive monitoring may be avoided.

Animals↗

PubMed1994

Pharmacologic intervention can reestablish baseline hemodynamic parameters during laparoscopy.

BACKGROUND: Several studies in both animal models and human beings have shown that CO2 abdominal insufflation for laparoscopy can cause a variety of alterations in hemodynamic and pulmonary physiology. These physiologic changes could potentially have deleterious effects in patients with underlying cardiopulmonary disease. METHODS: We prospectively evaluated 15 patients with preexisting heart and/or lung disease to determine whether the use of invasive monitoring would allow early identification and treatment of these physiologic alterations and thus enable laparoscopy to be performed safely in this group of patients. RESULTS: CO2 abdominal insufflation caused statistically significant increases in systemic vascular resistance, mean arterial pressure, left ventricular stroke work index, and pulmonary capillary wedge pressure along with a concomitant decrease in cardiac index and oxygen delivery in these patients. The use of intravenous nitroglycerin resulted in a rapid return of the systemic vascular resistance, mean arterial pressure, pulmonary capillary wedge pressure, and cardiac index to baseline levels. No significant intraoperative or postoperative cardiac or pulmonary complications were noted. CONCLUSIONS: These results suggest that laparoscopy with CO2 pneumoperitoneum can be safely performed in high-risk patients if appropriate monitoring and pharmacologic interventions are used.

Aged↗

PubMed1992

Treatment of peripancreatic fluid collections in patients with complicated acute pancreatitis.

We reviewed an experience with treatment of peripancreatic fluid collections in patients with complicated acute pancreatitis to identify clinical and computed tomography (CT) parameters that are helpful in the selection of patients for treatment and to assess treatment outcome. The extent of CT abnormalities determined a CT severity score (mild = 1, severe = 4). From 1985 to 1990, 650 patients were hospitalized with acute pancreatitis; a peripancreatic fluid collection was found in 36 patients (5.5 percent). Ten of 11 patients with successful outcome after no invasive treatment (group 1) had a low CT severity score of 1 or 2; mean serum albumin was 4.0 gram percent. Of 25 patients who had some form of drainage, 12 had a high CT severity score of 3 or 4 (p < 0.05) and a mean serum albumin of 3.4 grams percent (p < 0.05). Nine patients had only operative drainage (group 2) and 16 had CT-directed percutaneous catheter drainage (group 3). In group 3, percutaneous catheter drainage successfully drained the fluid collection in six patients, while ten patients needed an operation, in addition to percutaneous drainage, to effectively débride and drain the necrotizing pancreatic problem. As a result of the current review, we propose an algorithm for treatment of these patients.

Acute Disease↗

PubMed1988

Leucine and the intestinal phase of gastric acid secretion.

The intestinal phase of gastric acid secretion is mediated by the putative hormone entero-oxyntin. The release of the hormone has been demonstrated in both dog and rat models during an intestinal meal of liver extract. The maximal gastric acid response to pentagastrin is augmented by the presence of liver extract in the intestine; this phenomenon serves as a bioassay for entero-oxyntin. We tested the hypothesis that one or more amino acids in liver extract causes the release and/or action of entero-oxyntin. Anesthetized rats, prepared with bilateral cervical vagotomies, received jejunal perfusion of mannitol (control), liver extract, or an amino acid. Intravenous pentagastrin was administered simultaneously at a dose known to produce maximal gastric acid output in rats. Our results show that of the amino acids tested, only leucine produced a significant augmentation of maximal pentagastrin-stimulated gastric acid secretion when compared with controls.

Amino Acids↗

PubMedDate not supplied

Preclinical experimental therapeutic approaches in soft tissue sarcoma.

Soft tissue sarcomas are relatively rare tumors that are generally treated with a multimodality approach including surgery, chemotherapy, and radiation therapy. Despite this aggressive tri-modality therapy, greater than 50% of soft tissue tumors will recur and result in diffuse metastatic spread of disease and ultimately death of the patient. It is this clinical scenario that drives the development of preclinical experimental studies designed to explore alternative treatments or enhance the effectiveness of existing therapies. Rapid developments in the field of molecular biology have led to the understanding of basic cellular processes governed by oncogenes and tumor suppressor genes. These cellular genes are sometimes overexpressed, mutated or even deleted from tumor cells. Cytogenetic analysis has led to the discovery of sarcoma fusion genes which encode for oncoproteins peculiar to specific subtypes of soft tissue sarcomas. These fusion genes have proved to be helpful in terms of diagnostic dilemmas and are now being used as targets in treatment strategies aimed at suppression of the cellular expression and action of these oncoproteins. Tumor suppressor genes such as p53 and the retinoblastoma tumor suppressor play important roles in growth inhibition and cell cycle progression. These tumor suppressors are often mutated or deleted in soft tissue sarcomas. Using gene therapy strategies, p53 can be reintroduced into sarcoma cells and has been shown to result in a dramatic decrease in cell survival. It also appears that p53 may sensitize these tumor cells to radiation and chemotherapy agents. Strategies which can drive tumor cells into programmed cell death pathways are also showing promise as novel treatment approaches to soft tissue sarcomas. This review will highlight some of the current research exploring novel treatment strategies aimed at molecular targets. Further development of these and other preclinical experimental programs are important in improving the outcome for patients with these rare soft tissue tumors.

Apoptosis↗

PubMedDate not supplied

Presentation, treatment, and outcome of local recurrence afterskin-sparing mastectomy and immediate breast reconstruction.

BACKGROUND: The local recurrence (LR) rate with skin-sparing mastectomy (SSM) and immediate breast reconstruction (IBR) has been reported as comparable to the LR rate after conventional mastectomy. However, limited data are available on the prognostic significance and management of LR following SSM. METHODS: A prospective database maintained at the University of Texas M. D. Anderson Cancer Center identified 437 SSMs performed for 372 invasive T1/T2 breast cancers between 1986 and 1993. RESULTS: Twenty-three LRs were identified, with a LR rate of 6.2% (23/372). Twenty-two of these (96%) presented as palpable skin-flap masses. The median time to recurrence was 25 months (range, 3 to 98 months). Fourteen patients were treated with a combination of surgery and systemic therapy. Resection of the reconstructed breast was performed in only three patients. Complete local control of the recurrent disease was achieved in 17 patients (74%). Nine patients (39%) developed distant metastatic disease. At a median follow-up of 26 months, 14 of 23 patients (61%) are alive without evidence of disease, and 7 (30%) have died from breast cancer. CONCLUSIONS: Because LR rate with SSM is low and likelihood of local control and survival is high, SSM and IBR is an acceptable treatment option for early stage breast cancer.

Adult↗

PubMedDate not supplied

Lymphoscintigraphy as a predictor of lymphatic drainage from cutaneous melanoma.

BACKGROUND: If cutaneous lymphoscintigraphy (CL) is accurate in predicting the draining lymph node basins at risk from primary axial melanomas, then regional metastases should only occur in those lymph node basins identified by CL. METHODS: This study is a retrospective review of patients undergoing CL for primary axial melanomas from June 1, 1985, until June 31, 1992. Data retrieved included age, gender, number of basins identified, location of basins identified, management of basins, recurrence in lymphatics, development of distant disease, and long-term follow-up. RESULTS: A total of 181 patients underwent elective LND, and 48 patients (27%) had melanoma in the nodes within the dissected basin. Of these 181 patients, seven developed nodal metastases as their site of first recurrence. All seven recurrences were seen at sites dissected or at sites indicated by CL, which the primary surgeon elected not to treat initially. Of the 116 patients observed, 16 (14%) developed lymph node metastases as their first site of recurrence. Fifteen of these 16 patients had their site of lymph node metastases predicted by CL. In this study, CL predicted 98.6% of all lymph node metastases. CONCLUSIONS: The high overall reliability of CL as demonstrated by long-term follow-up indicates that the information obtained by CL can be reliably used to guide intervention. Initial evaluation of patients with high-risk cutaneous melanomas at sites with ambiguous lymphatic drainage must include CL in order to determine the draining lymph node basins and to plan therapy.

Adolescent↗

PubMedDate not supplied

Feasibility of breast conservation therapy in metachronous or synchronous bilateral breast cancer.

BACKGROUND: The optimal management of contralateral breast cancer (CC) in patients previously treated with breast-conserving therapy (BCT) is unclear, as is whether these patients continue to choose BCT as the preferred treatment of their second breast cancer. METHODS: Of 1328 patients treated with BCT at The University of Texas M. D. Anderson Cancer Center between 1958 and 1994, 63 developed a contralateral breast cancer. We reviewed the charts of these patients retrospectively, and standard demographic and treatment variables were evaluated. Survival was analyzed by the Kaplan-Meier method and subgroups by chi2 analysis. RESULTS: Twenty-nine percent of the patients had a family history of breast cancer. First breast cancers were detected by patient or physician in 67% of cases and by mammogram in 17% of cases, compared to 59% and 36%, respectively, of CC (P = .04). Median time to development of CC was 61 months. Sixty percent of the initial tumors were AJCC stage 0 or I with a median size of 2 cm, whereas 74% of the CC were stage 0 or I (P = .02), with a median size of 1.5 cm. Eighty-seven percent of patients chose BCT for treatment of CC. There were few treatment-related complications. Recurrence rates were not significantly different from those of patients undergoing BCT for the initial cancer (P = .47), and 5- and 10-year actuarial survival rates after the first cancer were 93% and 76%, respectively. Median follow-up was 134 and 56 months from the time of diagnosis of the initial cancer and CC, respectively. CONCLUSIONS: Because contralateral breast cancer often is detected at an early stage, there are few treatment-related complications, and the risk of recurrence is no different from that for the initial cancer, BCT is an acceptable and desirable option for appropriately selected patients with metachronous or synchronous bilateral breast cancers.

Adult↗

PubMedDate not supplied

Local recurrence and survival among black women with early-stage breast cancer treated with breast-conservation therapy or mastectomy.

BACKGROUND: Black women with breast cancer have significantly worse survival rates and receive diagnoses at relatively younger ages, compared with white patients with breast cancer, in the United States. Young age at diagnosis has been associated with increased risk for local recurrence (LR) after breast-conservation therapy (BCT). The goal of this study was to evaluate the impact of age and BCT on LR and survival rates among black patients with breast cancer. METHODS: The records for 363 black women treated for breast cancer (excluding stage IV disease) at a comprehensive cancer center were reviewed. RESULTS: Fifty-eight percent of patients (n = 211) had tumors < or = 5 cm in diameter. Forty-two of these patients (19.9%) received BCT; the LR rate for this group was 9.8%. A total of 168 patients (79.6%) underwent mastectomy; the LR rate for this group was 8.9%. Data on the primary operation were unavailable for one patient. Five-year disease-free survival rates were similar for patients treated with BCT and those treated with mastectomy (88% and 73%, respectively). LR was associated with significant decreases in 5-year overall survival rates for both the BCT group (67% vs. 95%, P < .01) and the mastectomy group (43% vs. 76%, P < .01). LR and 5-year disease-specific survival rates were similar for patients <50 years of age and patients > or = 50 years of age, regardless of treatment. CONCLUSIONS: LR and survival rates are not compromised by the use of BCT among black American patients. LR is associated with an increased risk of breast cancer death, regardless of treatment type. Younger age at diagnosis was not associated with an increased rate of LR after BCT in this series.

Adolescent↗

PubMedDate not supplied

Re-resection with brachytherapy for locally recurrent soft tissue sarcoma arising in a previously radiated field.

PURPOSE: The use of further radiotherapy among patients with soft tissue sarcoma that recurs in a previously irradiated area is controversial. Presented is a review of our 7-year experience with brachytherapy for recurrent soft tissue sarcoma. METHODS: A retrospective review was performed of 26 patients who underwent perioperative brachytherapy between 1990 and 1997 for recurrent soft tissue sarcoma. In all cases, the sarcoma recurred within a previously irradiated field. After-loading brachytherapy catheters were placed at the time of surgical extirpation of the sarcoma within a single-plane implant by use of 1-cm intercatheter spacing. Insertion of the radioactive 192Ir wire was delayed until the fifth to seventh postoperative day to allow initial wound healing. The prescribed dose rate for the 192Ir wire ranged between 50 and 80 cGy an hour, and the dose was specified at 0.5 cm from the plane of the implant. The anatomic locations treated included lower extremity (N = 10), upper extremity (N = 7), trunk (N = 7), and head and neck (N = 2). RESULTS: Total tumor extirpation, confirmed by negative frozen section margins, was accomplished in all cases. The mean dose of external-beam irradiation received before brachytherapy was 55.6 Gy +/- 1.8 Gy (range, 30.0 to 70.3 Gy). The mean dose of radiation prescribed at the implant procedure was 47.2 Gy +/- 1.6 Gy (range, 11.0 to 50.0 Gy). A tissue transfer flap was placed over the bed of resection in 13 cases. Complications occurred in five patients including, three with wound breakdown, one with osteonecrosis, and with neuralgia. Operative intervention was required in four of the five patients with complications; each of the patients requiring operative intervention for wound-related complications had undergone primary wound closure without tissue transfer. Recurrence of disease occurred in 13 patients: nine local and four distant metastases. The median follow-up was 16 months (range, 2 to 73 months). The 5-year local recurrence-free, distant recurrence-free, disease-free, and overall survival rates after brachytherapy were 52%, 75%, 33%, and 52%, respectively. CONCLUSION: Re-irradiation of recurrent soft tissue sarcoma by brachytherapy in conjunction with resection can be performed with acceptable complication rates. Local control can be achieved for the majority of patients who would otherwise require more radical surgical procedures.

Adult↗

PubMedDate not supplied

Pathologic tumor response in the breast following neoadjuvant chemotherapy predicts axillary lymph node status.

PURPOSE: Neoadjuvant chemotherapy is becoming the standard of care for locally advanced breast cancer. This study was performed to determine whether pathologic primary tumor response to neoadjuvant chemotherapy might predict axillary lymph node status and so be used to identify patients in whom surgery could be effectively limited to biopsy of the previous primary tumor site without axillary dissection. PATIENTS AND METHODS: Between 1992 and 1996, 170 consecutive patients with locally advanced breast cancer were treated in a prospective trial with four preoperative cycles of 5-fluorouracil, doxorubicin, and cyclophosphamide. Disease was staged before initiation of preoperative chemotherapy and before surgery. Segmental resection with axillary lymph node dissection or modified radical mastectomy was performed first, followed by postoperative chemotherapy and radiation therapy of the breast (or chest wall) and regional lymphatics. Patient and tumor characteristics associated with complete versus incomplete pathologic primary tumor response to neoadjuvant chemotherapy and correlation between primary breast tumor pathologic response and axillary lymph node status found at surgery were analyzed. RESULTS: Of 156 evaluable patients, 30 patients (19%) had primary breast tumors that were completely eliminated after induction chemotherapy based on histologic assessment. Nineteen of those 30 patients (63%) had negative axillary lymph nodes at dissection, compared with 13 patients (33%) of the 40 who had a near-complete pathologic primary tumor response (< or = 1 cm3 remaining) and only 15 patients (17%) of the 86 who had > 1 cm3 tumor remaining in the pathology specimen of the breast primary. Of the 22 patients with a complete pathologic response in the breast and a clinically negative axilla after induction chemotherapy, axillary dissection revealed positive lymph nodes in four. These four patients had only one or two positive lymph nodes. DISCUSSION: Because initial clinical regression of primary tumor with neoadjuvant chemotherapy is considered an excellent prognostic indicator and because patients with locally advanced breast cancer routinely receive local and regional radiation treatment followed by additional chemotherapy, the role of breast and axillary surgery has been questioned. In this study, a complete pathologic response of the primary tumor to induction chemotherapy is highly predictive of negative axillary lymph node status. Therefore, axillary lymph node dissection may be omitted in certain subsets of patients who have a biopsy-proven complete pathologic response in the primary tumor and a clinical negative axillary examination. Further prospective, randomized investigation is needed to confirm this finding.

Adult↗