Abstract ES11-3: Microsurgical treatment of lymphedema

Lymphedema is a chronic, debilitating condition that causes physical and psychological morbidity, affecting up to 250 million people worldwide. In the United States and other developed countries, cancer and its treatments are the most common causes of lymphedema. Lymphedema can evolve into progressive swelling, fibrosis, functional deficits, and chronic infections, thus adversely affecting quality of life and health care costs.

Unfortunately, no definitive treatment for lymphedema currently exists. The advents of microsurgery, and more recently supermicrosurgery, have had a major impact on the evolution of these physiologic procedures, which have gained popularity to help reduce the severity of lymphedema.

Lymphatic Bypass

LVB are typically performed through incisions 2-3 cm in length and the number of bypasses can vary depending on a patient as well as a surgeon. In our prospective study in 100 consecutive patients, we have found that LVB can be effective in reducing lymphedema severity, particularly in patients with early-stage, upper-extremity lymphedema with reasonable amount of intact functioning lymphatic vessels and minimal tissue fibrosis.

One recent technological advance in lymphovenous bypass procedures is the use of indocyanine green (ICG) fluorescence lymphangiography to map lymphatic vessels. ICG fluorescence lymphangiography enables surgeons to locate and make incisions precisely over functional lymphatic vessels for the lymphovenous bypass, substantially reducing operating time and may significantly improve the outcomes of LVB surgeries.

Vascularized Lymph Node Transfer

This procedure aims to bring vascularized tissue and healthy lymph nodes into sites affected by lymphedema. A flap containing lymph nodes can then be harvested typically from either the cervical region, axillary region or from the inguinal region.

One proposed theory for mechanism is that lymphangiogenesis occur via growth factors produced by the transplanted lymph nodes and thereby bridging lymphatic pathways. A second proposed theory of mechanism is that vascularized lymph node transfer act as a lymphatic pump. Recently, simultaneous breast reconstruction using the transverse lower abdominal flap harvested with inguinal lymph nodes have gained popularity as a convenient option for lymphedematous women who desire reconstruction after mastectomy.

Conclusions

Currently there is no cure for lymphedema. Worldwide interest in using microsurgical procedures to treat lymphedema is gaining momentum. However, there is no consensus on the indications for which procedure to perform, when to intervene, or how to comparatively grade outcomes. We need further research and better understanding of lymphatic anatomy and lymphedema pathophysiology. In addition, more prospective and controlled studies are needed to objectively evaluate the outcomes of various treatment methods.

Citation Format: Chang D. Microsurgical treatment of lymphedema [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr ES11-3.

Long- and short-range structural characteristics of pea starch modified by autoclaving, α-amylolysis, and pullulanase debranching

Pea starch (S) was modified by autoclaving (A), α-amylolysis (E), and pullulanase debranching (P), the effect of pretreatments including autoclaving and α-amylolysis on the structural modifications to the pullulanase debranched starch was investigated. All processed pea starch was transformed from a C- to a B-type crystalline structure. The power law exponent (α) ranging from 1.85 to 2.64 suggested the existence of mass fractal structure. Compared with native starch, all treatments applied caused an enhanced short-range order which was reflected by the increased values of α, degree of double helix (DD), degree of order (DO), and double helix content based on SAXS, FTIR, and 13CNMR observations. The processed starch sample of AS, and APS exhibited the highest DO, and α values, as well as the stronger absorption peak between 3000 and 3695 cm-1on FT-IR spectrum. AEPS exhibited the significantly highest double helix content, indicating that the higher extent of degradation induced by the combined treatments of autoclaving, α-amylolysis, and pullulanase debranching would give the molecular chains a higher alignment opportunity for the evolution towards coil-to-helix transition. The results would be helpful for better understanding the structure-processing relationship and to provide theoretical foundation for the development of food ingredients with targeted functional properties.

Neuroinvasive West Nile Virus Post-Heart Transplantation: A Case Report

First described in the United States in the late 1990s, West Nile virus (WNV) infection following solid organ transplantation is a rare but life-threatening complication. The many ways in which WNV may be acquired, patient specific risk factors, and variability in clinical severity present challenges to health care providers caring for these patients.

Peritoneal Carcinomatosis from an Unknown Primary Site. Management of 15 Patients

Aims and background

Peritoneal carcinomatosis from an unknown primary site is a rare and ill-defined entity. This work attempts to identify clinical and pathological features of patients with this disease and report the results of an aggressive combined treatment modality.

Methods

Retrospective analysis was performed of medical records of 15 patients with peritoneal carcinomatosis with no primary site identified at a single institution between 1989 and 2000. A primary gastrointestinal cancer was ruled out after a thorough endoscopic and radiologic work-up and complete exploratory surgery.

Results

Four women and 11 men were identified; the average age was 49 years. All patients had cytoreductive surgery with peritonectomies; 4 patients underwent a second-look operation. Perioperative intraperitoneal chemotherapy was given to 10 of the 15 patients, and 9 patients received post-cytoreduction chemotherapy given intraperitoneally (1), systemically (7) or both intraperitoneally and systemically (1). Overall median survival from diagnosis was 19.0 months; 1 patient is alive with disease at 21 months; and 3 patients are disease-free at 17, 38, and 60 months from diagnosis. Significant positive predictive factors for survival were a small volume of ascites (P = 0.02), a large number of peritonectomies performed (P = 0.001), second-look cytoreduction (P = 0.003), perioperative intraperitoneal chemotherapy (P = 0.008) and postoperative chemotherapy (P = 0.01), either intraperitoneal or systemic.

Conclusions

Peritoneal carcinomatosis from an unknown primary site is a rare subset of primary peritoneal malignancy. Aggressive treatment may provide prolonged palliation with occasional long-term survival.

Pharmacokinetics of Intraperitoneal Gemcitabine in a Rat Model

BACKGROUND

Gemcitabine (2'-2' difluorodeoxycytidine) has been shown to possess a broad spectrum of antitumor activity against various malignancies, particularly pancreatic carcinoma. For cancers occurring within the abdominal cavity, the advantage of intraperitoneal (i.p.) chemotherapy over intravenous (i.v.) chemotherapy is the high drug concentration that can be achieved locally. In addition, the cytotoxic effect of several anticancer agents can be enhanced by hyperthermia. Using a rat model, this study was designed to compare i.p. vs i.v. gemcitabine and to evaluate the effect of hyperthermia on i.p. gemcitabine.

METHODS

In the first phase of this study, 18 Sprague Dawley rats were given a single dose of gemcitabine then randomized into three groups according to dose and route of delivery of chemotherapy (12.5 mg/kg--i.v., 12.5 mg/kg--i.p. or 125 mg/kg--i.p.). In a separate experiment (phase 2), 12 Sprague Dawley rats were given a continuous i.p. perfusion of gemcitabine (12.5 mg/kg in 150 mL total perfusate) and randomized into two groups according to the temperature of the peritoneal perfusate (normothermic or hyperthermic). During the course of both experiments, peritoneal fluid and blood were sampled using a standardized protocol. At the end of the procedure the rats were sacrificed and all urine was extracted. Selected tissue samples were taken from rats in the second phase of the study. The concentration of gemcitabine in all samples was determined by high performance liquid chromatography (HPLC).

RESULTS

When gemcitabine was delivered at 12.5 mg/kg (phase 1) the area under the curve (AUC) was significantly higher with i.p. administration as compared to i.v. administration (P = 0.001). The AUC ratio (AUC peritoneal fluid/AUC plasma) was 12.5+/-3.2 for i.p. delivery as opposed to 0.2+/-0.2 for i.v. delivery (P = 0.0002). The AUC ratio for i.p. gemcitabine at 125 mg/kg was 26.8+/-5.8. Although there was no significant difference in drug concentrations between samples from the normothermic and hyperthermic groups, all tissue samples (except stomach) in the hyperthermic group exhibited increased gemcitabine concentrations.

CONCLUSION

These experiments demonstrated that the exposure of peritoneal surfaces to gemcitabine is significantly increased with i.p. gemcitabine. Intraabdominal hyperthermia had no significant effect on the pharmacokinetics of i.p. gemcitabine but there was evidence of increased absorption of gemcitabine in most intraabdominal tissues. Due to the likelihood of a high incidence of microscopic residual disease after resection of a pancreatic carcinoma, clinical studies to evaluate i.p. hyperthermic gemcitabine may be indicated.