IU Indianapolis ScholarWorks :: Browsing by Author "Ahmed, Shahnur"

Browsing by Author "Ahmed, Shahnur"

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142. Optimization of the Murine Hindlimb Lymphedema Model
(Wolters Kluwer, 2025-04-24) Ahmed, Shahnur; Mohan, Ganesh; Sullivan, Steven J.; Jorge, Miguel; Sinha, Mithun; Hassanein, Aladdin H.; Surgery, School of Medicine
PURPOSE: Secondary lymphedema is limb swelling from lymphatic injury. It frequently occurs following lymph node dissection and radiation during the treatment of malignancies such as breast cancer or melanoma. The murine tail is the most commonly used model to study secondary lymphedema and involves full thickness tail skin excision and lymphatic vessel disruption. The murine hindlimb model, which has been less frequently used in the literature, offers a more clinically translatable method. However, there is inconsistency and variability, including the benefit of radiation, which have contributed to the model being less widely adapted than the tail model. The purpose of this study is to 1) optimize the murine hindlimb lymphedema to achieve consistent results and 2) assess the effect of radiation on outcome in the murine hindlimb model. METHODS: C57BL/6 mice either underwent 20 Gy irradiation of one hindlimb seven days prior to surgery (n=11) or no preoperative radiation (n=9). For all mice, a circumferential skin incision was created at the proximal hindlimb exposing the subcutaneous soft tissues. Lymphatics were identified with isosulfan blue dye injection into the paw and disrupted. Popliteal lymph nodes were excised. The skin was sutured leaving a 3 mm gap. The contralateral hindlimb served as the control. Paw thickness and calf thickness measurements were obtained at weekly intervals and indocyanine green (ICG) near-infrared laser lymphangiography was used to assess lymphatic function. RESULTS: For the irradiated mice, the average paw thickness of the operated hindlimb on postoperative day (POD) 14 was 3.5±0.3 cm compared to 2.1±0.05 cm on the contralateral limb (p=0.0001). At POD-90, the average paw thickness of the irradiated, operated hindlimb was 2.4±0.1 cm compared to 2.1±0.1 cm for the contralateral limb (p=0.01). ICG lymphangiography at 24-hours postinjection on POD-42 demonstrated an average signal intensity of 97.7±28.5 arbitrary fluorescent units (AFU) in the operated hindlimb compared to 33.6±6.2 AFU in the non-operated hindlimb (p=0.003). In the mice that did not undergo radiation, the average paw thickness was 2.5±0.2 cm on POD-42 was greater than the contralateral limb (2.1±0.1 cm) (p=0.0002) but smaller than hindlimbs that underwent radiation (3.2±0.1 cm) (p=0.0002). The nonradiated mice had greater paw thickness than the contralateral control until POD-56 whereas the radiated mice sustained significant paw thickness until Day 90. CONCLUSION: Radiation of the murine hindlimb model results in sustained lymphedema compared to non-irradiated mice. The murine hindlimb lymphedema model is clinically more translatable than the murine tail model and includes limb lymphatic vessel disruption, and popliteal lymphadenectomy and ideally radiation for consistent results with lymphedema sustained for 90 days.
177. Prophylactic Absorbable Antibiotic Beads For High Risk Implant-based Reconstruction: A Single Institution Pilot Study
(Wolters Kluwer, 2023-05-19) Ahmed, Shahnur; Lee, Jason T. C.; Roth, Dylan D.; Liu, Steven; Fisher, Carla S.; Fan, Betty; Imeokparia, Folasade; Ludwig, Kandice; Lester, Mary E.; Hassanein, Aladdin H.; Surgery, School of Medicine
PURPOSE: Infections are problematic in implant-based reconstruction after mastectomies. Infection rates have been reported to be as high as 31%. Strategies to reduce the risk of infection include various antibiotic irrigation solutions, “no-touch” techniques, optimizing sterility, and empiric antibiotic use for skin flora coverage. Absorbable antibiotic beads have been well described for other indications, including orthopedic and pressure sore reconstruction. The purpose of this study is to evaluate the use of prophylactic biodegradable antibiotic beads during pre-pectoral and sub-pectoral implant-based breast reconstruction following mastectomy. METHODS: A single-center retrospective review of patients who underwent implant-based breast reconstruction post-mastectomy between 2019 to 2022. Patients were divided into two groups: Group I were deemed “high risk” by the senior author and received biodegradable antibiotic beads (1 gram vancomycin, 240 mg gentamicin) during tissue expander or implant reconstruction (pre-pectoral or subpectoral) while Group II (control) had no antibiotic beads. Demographic data, diabetes, body mass index (BMI), implant plane (pre-pectoral or sub-pectoral), smoking and use of mesh were recorded. Outcome variables included postoperative cellulitis or infection requiring oral or intravenous antibiotics and tissue expander loss at 90 days. RESULTS: In our study period, 19 patients (36 total implants/expanders) received biodegradable antibiotic beads during implant-based breast reconstruction (Group I). There were 174 patients (290 total expanders) who did not receive antibiotic beads (Group II). Patients in Group I had a history of previous expander/implant infection in 73.6%. Pre-pectoral placement of implants occurred in 84.2% of patients in Group I and 74.1% in Group II. Diabetes was prevalent in 15.8% of Group I compared to 5.7% seen in Group II patients. The mean BMI in Group I was 30.5 kg/m2 compared to 27.8 kg/m2 in Group II (p-value 0.88). Implant infection rate of Group I at 90 days was 8.3% (3/36 total expanders) compared to 8.6% (25/290 total expanders) in Group II. Implant loss in Group I was 5.5% (2/26 total expanders) compared to 7.6% (22/290) in Group II. CONCLUSION: The incidence of infection in high risk patients who have absorbable antibiotic beads placed during the time of reconstruction appears to be normalized to the control group in this pilot study, suggesting that absorbable antibiotic beads may decrease postoperative infection complications. Future studies may further clarify its benefit in selected groups.
65. Prophylactic Absorbable Antibiotic Beads: Effect on Tissue Expander Reconstruction Outcomes Following Mastectomy Skin Necrosis
(Wolters Kluwer, 2025-04-24) Ahmed, Shahnur; Zaidi, Shozaf S.; Fisher, Carla S.; Ludwig, Kandice K.; Imeokparia, Folasade O.; VonDerHaar, R. Jason; Bamba, Ravinder; Danforth, Rachel M.; Hassanein, Aladdin H.; Lester, Mary E.; Surgery, School of Medicine
PURPOSE: Mastectomy skin necrosis is problematic in tissue expander reconstruction with rates between 7 to 30%. Partial or full-thickness skin necrosis may harbor bacterial colonization promoting infection and risk of implant loss. Absorbable antibiotic-impregnated calcium-sulfate antibiotic beads have been described to reduce tissue expander (TE)/implant infection when used prophylactically for prepectoral breast reconstruction. The purpose of this study is to evaluate the effect of absorbable antibiotic beads on outcomes in patients who develop mastectomy skin necrosis after immediate postmastectomy tissue expander breast reconstruction. METHODS: A single-center retrospective review was performed for patients who underwent mastectomy, immediate prepectoral TE reconstruction on the same day (2018-2024). Patients who developed mastectomy skin necrosis were included. Patients were divided into two groups: Group 1 (absorbable antibiotic beads with TE placement) and Group 2 (no antibiotic beads with TE). Demographical information was recorded. Surgical-site infection (90-days) and implant removal were the outcome variables. RESULTS: The study included 61 patients (75 total breasts with necrosis) who underwent prepectoral TE breast reconstruction following mastectomy and developed mastectomy skin necrosis. The patients included in the study with mastectomy skin necrosis were 12 patients in Group 1 (16 breasts) and 49 patients in Group 2 (59 breasts). Baseline characteristics were not significantly difference between groups (p=1). There was no difference between nipple-sparing mastectomy or skin-sparing mastectomy between groups (p=0.1094). Acellular dermal matrix was used in 66.7% (8/12) of Group 1 compared to 83.7% (41/49) of Group 2 (p=0.2285). Operative management of mastectomy skin necrosis including debridement and reclosure was required in 50% (6/12) of Group 1 compared to 69.4% (34/49) of Group 2 patients (p=0.3093). There was one occurrence (6.3%, 1/16 TEs) of surgical-site infection in Group 1 and 35.6% (21/59 TEs) in Group 2 (p=0.0288). TE removal resulted in 6.3% (1/16 TEs) in Group 1 and 33.9% (20/59 TEs) in Group 2 (p=0.0310). The mean follow-up time was 189 days (range 146-236 days). CONCLUSIONS: Patients who develop mastectomy skin necrosis after prepectoral tissue expander reconstruction may experience lower rates of TE removal and infection when prophylactic absorbable antibiotic-impregnated beads are used. Patients who develop mastectomy skin necrosis are at high risk for infection and TE loss. Prophylactic antibiotic beads used at the time of mastectomy with prepectoral TE reconstruction decrease the risk of infection and TE loss in patients who experience mastectomy skin necrosis.
80. Lymphatic Preconditioning: Novel Investigation Of A “Lymphatic Delay Phenomenon”
(Wolters Kluwer, 2024-04-19) Hulsman, Luci; Mohan, Ganesh; Ahmed, Shahnur; Jorge, Miguel D.; Sullivan, Steven J.; Mohammed, Imran; Sinha, Mithun; Hassanein, Aladdin H.; Surgery, School of Medicine
Background: The vascular delay phenomenon is a well-described concept of flap physiology with many clinical applications used to increase flap viability. The approach employs a staged surgical procedure with selective partial disruption of the flap’s blood supply to increase the robustness of the remaining blood supply, followed by interval flap transfer 7-10 days later. While this vascular delay phenomenon has been thoroughly studied, no investigation has been performed to determine if a similar “delay phenomenon” exists for lymphatic vessels. Lymphedema frequently occurs following injury of lymphatics during lymph node dissection. The purpose of this study was to evaluate whether lymphatic preconditioning with staged disruption of lymphatics can be protective against lymphedema. Methods: The standard murine tail lymphedema model was utilized which involves creating a 3 mm circumferential skin excision by the base of the tail and surgically clipping two lymphatics. This standard model was used for a control (Group 1, Control A, n=6). A second control (Group 2, Control B, n=5) had 3 mm circumferential skin excision, one tail lymphatic clipped at that level, and an immediate second hemi-circumferential skin excision on the more proximal tail with disruption of the other remaining lymphatic. Group 3 (experimental lymphatic preconditioning, n=6), had a 3 mm full thickness skin excision by the base of the tail, disruption of one tail lymphatic at that level (leaving one lymphatic vessel intact) followed by staged hemi-circumferential skin excision with disruption of the remaining lymphatic vessel 7 days later. Tail volume was assessed with tail measurements using the truncated cone equation. Immunohistochemistry and histology was sent. Results: Group 3 (experimental lymphatic preconditioning) had a change in tail volume of 79.1 mm3 compared to Group 1 (Control A) 154.6 mm3 (p=0.03) and Group 2 (Control B) 126.6 mm3 (p=0.05) at 28 days post-lymphatic injury. Conclusion: Mice that underwent lymphatic preconditioning with partial lymphatic injury followed by staged completion of lymphatic disruption 7 days later exhibited less tail swelling. This study demonstrates evidence for a novel concept of “lymphatic delay phenomenon” parallel to the well-known vascular delay phenomenon. Lymphatic preconditioning has potential translational clinical applications for protective effects to minimize lymphatic dysfunction.
Direct-to-Implant in the Era of Prepectoral Breast Reconstruction: Evaluation of the National Trend in 59,313 Patients
(Wolters Kluwer, 2025-03-18) Ahmed, Shahnur; Baril, Jackson A.; Fisher, Carla S.; Danforth, Rachel M.; Bamba, Ravinder; Lester, Mary E.; Hassanein, Aladdin H.; Surgery, School of Medicine
Implant-based Breast Reconstruction Salvage with Negative Pressure Wound Therapy with Instillation: An Evaluation of Outcomes
(Wolters Kluwer, 2024-09-03) Ahmed, Shahnur; Hulsman, Luci; Imeokparia, Folasade; Ludwig, Kandice; Fisher, Carla; Bamba, Ravinder; Danforth, Rachel; VonDerHaar, R. Jason; Lester, Mary E.; Hassanein, Aladdin H.; Surgery, School of Medicine
Background: Implant infection is problematic in breast reconstruction. Traditionally, infected tissue expanders (TE)/implants are removed for several months before replacement, resulting in breast reconstruction delay. Salvage involving device removal, negative pressure wound therapy with instillation and dwell (NPWTi-d) placement, and early staged TE/implant replacement within a few days has been described. The purpose of this study was to compare outcomes of the NPWTi-d salvage pathway with traditional implant removal. Methods: A retrospective review was performed on patients who underwent implant-based reconstruction and developed TE/implant infection/exposure requiring removal. Patients were divided into two groups. Group 1 had TE/implant removal, NPWTi-d placement, and TE/implant replacement 1-4 days later. Group 2 (control) underwent standard TE/implant removal and no NPWTi-d. Reinfection after TE/implant salvage, TE/implant-free days, and time to final reconstruction were assessed. Results: The study included 47 patients (76 TE/implants) in group 1 (13 patients, 16 TE/implants) and group 2 (34 patients, 60 TE/implants). The success rate (no surgical-site infection within 90 days) of implant salvage was 81.3% in group 1. No group 1 patients abandoned completing reconstruction after TE/implant loss versus 38.2% (13 of 34) in group 2 (P = 0.0094). Mean implant-free days was 2.5 ± 1.2 in group 1 versus 134.6 ± 78.5 in group 2 (P = 0.0001). The interval to final implant-based reconstruction was 69.0 ± 69.7 days in group 1 versus 225.6 ± 93.6 days in group 2 (P = 0.0001). Conclusions: A breast implant salvage pathway with infected device removal, NPWTi-d placement, and early TE/implant replacement was successful in 81.3%. Patients experienced 132 less implant-free days and faster time to final reconstruction.
Prophylactic Absorbable Antibiotic Beads for High-risk, Implant-based Prepectoral Reconstruction
(Wolters Kluwer, 2023-10-16) Ahmed, Shahnur; Lee, Jason T. C.; Roth, Dylan; Sinha, Mithun; Fisher, Carla; Fan, Betty; Imeokparia, Folasade; Ludwig, Kandice; Lester, Mary E.; Hassanein, Aladdin H.; Surgery, School of Medicine
Infections are problematic in postmastectomy implant-based reconstruction with infection rates as high as 30%. Strategies to reduce the risk of infection have demonstrated various efficacies. A prolonged course of systemic, oral antibiotics has not shown evidence-based benefit. Although absorbable antibiotic beads have been described for orthopedic procedures and pressure wounds, their use has not been well studied during breast reconstruction, particularly for prepectoral implant placement. The purpose of this study was to evaluate the selective use of prophylactic absorbable calcium sulfate antibiotic beads during high-risk implant-based, prepectoral breast reconstruction after mastectomy. Patients who underwent implant-based, prepectoral breast reconstruction between 2019 and 2022 were reviewed. Groups were divided into those who received antibiotic beads and those who did not. Outcome variables included postoperative infection at 90 days. A total of 148 patients (256 implants) were included: 15 patients (31 implants) who received biodegradable antibiotic beads and 133 patients (225 implants) in the control group. Patients who received antibiotic beads were more likely to have a history of infection (66.7%) compared with the control group (0%) (P < 0.01). Surgical site infection occurred in 3.2% of implants in the antibiotic bead group compared with 7.6%, but this did not reach statistical significance. The incidence of infection in high-risk patients who have absorbable antibiotic beads placed during the time of reconstruction seems to be normalized to the control group in this pilot study. We present a novel use of prophylactic absorbable antibiotic beads in prepectoral breast implant reconstruction.
Prophylactic Absorbable Antibiotic Beads: Effect on Postoperative Drain Management Following Breast Reconstruction
(Wolters Kluwer, 2025-03-03) Ahmed, Shahnur; Hajj, John P.; Bamba, Ravinder; Danforth, Rachel M.; VonDerHaar, Richard Jason; Lester, Mary E.; Hassanein, Aladdin H.; Surgery, School of Medicine
Prophylactic Buried Dermal Flap: A Simple Method for Axillary Reconstruction after Lymph Node Dissection
(Wolters Kluwer, 2024-09-12) Fallah, Kasra N.; Ahmed, Shahnur; Venardi, Andrew S.; Hulsman, Luci A.; Fisher, Carla S.; Ludwig, Kandice K.; Lester, Mary E.; Hassanein, Aladdin H.; Surgery, School of Medicine
Breast cancer-related lymphedema is characterized by progressive limb enlargement and occurs in up to 30% of breast cancer patients following axillary lymph node dissection (ALND). Immediate lymphatic reconstruction (ILR) is a preventative technique used to reduce lymphedema rates by performing lymphovenous anastomoses of disrupted afferent lymphatics. This study presents a novel method of axillary reconstruction following ALND using a buried dermal flap that provides local tissue with intact subdermal lymphatics to the axillary dead space. A single-center retrospective review was performed to assess breast cancer patients who underwent modified radical mastectomy without reconstruction between 2018 and 2023. Groups were divided into those who had ILR alone (group 1) and those who had buried dermal flap with attempted ILR (group 2). There were 31 patients included in this study: 18 patients in group 1 and 13 patients in group 2. Patient demographics, comorbidities, and breast cancer history were similar between the groups. There was no significant difference in the mean number of lymphovenous anastomoses performed (1.6 versus 1.7, P = 0.84). Mean operative time of 224.4 ± 51.9 minutes in group 1 was similar to 223.4 ± 30.4 minutes in group 2 (P = 0.95). We introduce a novel method of axillary reconstruction following ALND using a buried dermal flap that is inset into the axillary dissection space and over the area of ILR. We propose that it is an efficient accessory procedure to augment ILR by providing supplementary intact lymphatic channels to the area of lymphatic injury, while obliterating the axillary dead space.
The Lymphedematous Limb as a Donor Site for Breast Fat Grafting
(Wolters Kluwer, 2024-05-17) Ahmed, Shahnur; Mohan, Ganesh; Hulsman, Luci; Greene, Arin K.; Shaheen, Muhammad; Sinha, Mithun; Hassanein, Aladdin H.; Surgery, School of Medicine
Breast cancer-related lymphedema results in chronic upper limb swelling with subcutaneous deposition of fluid and fibroadipose tissue. Morbidity includes psychosocial distress, infection, and difficulty using the extremity. Operative management includes excisional procedures such as suction-assisted lipectomy to reduce abnormal subcutaneous fibroadipose tissue to improve limb volume. Patients who have had postmastectomy breast reconstruction often benefit from fat grafting. This report introduces the concept of fat grafting the breast using the lymphedematous arm as a donor site. This technique improves the volume of the limb by removing the excess subcutaneous adipose, and at the same time reconstructs the breast without adding a donor site not related to the breast cancer-related lymphedema.

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