Potential Conflicting Interests for Surgeons in End-of-Life Care
The American journal of hospice & palliative care, Jan 28, 2014
Thirty-day mortality represents a variable that is commonly used to measure the quality of surgic... more Thirty-day mortality represents a variable that is commonly used to measure the quality of surgical care. The definition of 30-day mortality and the application of a risk adjustment to its measurement may vary among different organizations comparing physician quality. In the midst of this confusion, conflicting interests arise for surgeons who must weigh the potential benefit of surgical interventions to individual patients versus the potential loss of access by future patients should 30-day mortality ratings be adversely affected. Similarly, surgeons may become adversely impacted by the lack of compensation from avoiding "high-risk" cases, but might face a more severe financial impact if they have a higher mortality rating compared to their peers.
Twenty-one cases of aortoenteric fistula: lessons for the general surgeon
The American surgeon, 2004
We retrospectively reviewed our experience from 1984 to 2001 with 21 cases of aortoenteric fistul... more We retrospectively reviewed our experience from 1984 to 2001 with 21 cases of aortoenteric fistula (AEF) in 19 patients. The majority of cases were in men (13 of 19, 68%). One AEF was spontaneous, the other 20 developed after prior vascular reconstruction (95%). The majority of AEF were duodenal (48%) followed by small bowel (38%), colon (10%), and esophageal AEF (5%). The proximal anastomosis of the prior vascular repair was the site of AEF origin in 62 per cent of cases, the distal anastomosis accounted for 19 per cent, and the body of the graft for 14 per cent. The intestinal repair was chosen on a case-by-case basis by the general surgeon and consisted of a simple primary repair in 48 per cent, resection with primary anastomosis in 38 per cent, and patching with pleura or omentum in individual cases. Colostomies were created in the two cases with colonic AEF. The duodenum was excluded in one of 10 duodenal AEF. Six patients (32%) died in the 90 days following surgery. The bigges...
Primary malfunction of a peritoneal dialysis catheter due to encasement in an encapsulating sheath
Peritoneal dialysis international: journal of the International Society for Peritoneal Dialysis
Obstruction of the catheter is one of the potentially serious complications of peritoneal dialysi... more Obstruction of the catheter is one of the potentially serious complications of peritoneal dialysis. Dislocation of the tip of the catheter, intraluminal fibrin formation, and omental wrapping are among the most common etiologies of peritoneal dialysis catheter malfunction that necessitate correction. Here we present a rare case of primary malfunction of a newly placed catheter in which multiple attempts to restore the patency by minimally invasive procedures were unsuccessful. Laparoscopy revealed a thick encapsulating sheath around the entire length of the catheter as the etiology of complete obstruction, without involvement of other intra-abdominal structures. The sheath was opened and the catheter was pulled out in its entirety. There was no intraluminal or orifice obstruction and it subsequently functioned perfectly.
Sequential dermal-peritumoral radiocolloid injection for sentinel node biopsy for breast cancer: the University of Florida experience
The American surgeon
Although sentinel lymph node (SLN) biopsy is rapidly becoming the standard of care for small brea... more Although sentinel lymph node (SLN) biopsy is rapidly becoming the standard of care for small breast cancers the optimal radiocolloid injection technique remains controversial. We report our experience with sequential dermal-peritumoral radiocolloid injection that takes advantage of both techniques. One hundred eighteen patients with clinical stage T(is), T1, T2 and N0 breast cancer underwent SLN biopsy at the University of Florida. Twelve to 18 hours before surgery patients received either an injection of 0.5 to 1.0 mCi 50:50 filtered:unfiltered technetium sulfur colloid into the dermis overlying the tumor and/or a peritumoral injection of a 3 to 4-mCi of radiocolloid 30 minutes later. Dynamic lymphoscintigraphy was performed and the topographical location of all imaged lymph nodes was marked on the skin. The next morning the surgeon utilized a hand-held gamma probe to remove all SLN(s) defined as any lymph node with radioactive counts 10 per cent or more of the ex vivo counts of th...
Real-time, plausible visual and haptic feedback of deformable objects without shape artifacts is ... more Real-time, plausible visual and haptic feedback of deformable objects without shape artifacts is important in surgical simulation environments to avoid distracting the user. We propose to leverage highly parallel stream processing, available on the newest generation graphics cards, to increase the level of both visual and haptic fidelity. We implemented this as part of the University of Florida's haptic surgical authoring kit.
Good surgical training depends greatly on case experiences that have been difficult to model in s... more Good surgical training depends greatly on case experiences that have been difficult to model in software since current training technology does not provide the flexibility to teach and practice uncommon procedures, or to adjust a training scenario on the fly. The TIPS kit aims to overcome these limitations. To the expert, it presents visual and haptic tools that make illustrating procedures easy and can model unusual anatomic variations. For a non-specialist, it provides a locally customized learning environment and repeated practice in a safe environment. We used the toolkit to illustrate removal of the adrenal gland.
Lyon, R., Khalil, M.K., Johnson, T., Lok, B., Cendan, J. (2012, April). Team-based learners compared to individuals develop greater knowledge with less reported cognitive demand from a neurologic simulator. Session presented at the 5th International Cognitive Load Theory Conference, Tallahassee, FL
Understanding empathy training with virtual patients
Computers in Human Behavior, 2015
While the use of virtual characters in medical education is becoming more and more commonplace, a... more While the use of virtual characters in medical education is becoming more and more commonplace, an understanding of the role they can play in empathetic communication skills training is still lacking. This paper presents a study aimed at building this understanding by determining if students can respond to a virtual patient's statement of concern with an empathetic response. A user study was conducted at the [blinded] College of Medicine in which early stage medical students interacted with virtual patients in one session and real humans trained to portray real patients (i.e., standardized patients) in a separate session about a week apart. During the interactions, the virtual and 'real' patients presented the students with empathetic opportunities which were later rated by outside observers. The results of pairwise comparisons indicate that empathetic responses made to virtual patients were rated as significantly more empathetic than responses made to standardized patients. Even though virtual patients may be perceived as artificial, the educational benefit of employing them for training medical students' empathetic communications skills is that virtual patients offer a low pressure interaction which allows students to reflect on their responses.
Laparoscopic pancreatic surgery: what now and what next?
Current gastroenterology reports, 2009
In recent years, improved laparoscopic skill sets have expanded surgical management of pancreatic... more In recent years, improved laparoscopic skill sets have expanded surgical management of pancreatic disease to encompass pancreatic resection, tumor enucleation, debridement, and drainage. With the aid of radiologically guided drainage catheters, necrosectomy for acute pancreatitis can be delayed and accomplished laparoscopically in a select patient population. Pancreatic pseudocysts from chronic pancreatitis can now be approached via minimally invasive strategies, including emerging combined laparoscopic procedures and natural orifice transluminal endoscopic surgery. It is clear that laparoscopic pancreaticoduodenectomy is possible in experienced hands; pancreatic neoplasms in the body and tail are more suitable for laparoscopic procedures because distal pancreatic resection requires no reconstruction of the biliary or enteric tract. Laparoscopic staging of pancreatic tumors has decreased as preoperative radiographic imaging becomes more sensitive. Similarly, laparoscopic palliative ...
1. Curr Probl Surg. 2001 Apr;38(4):213-90. Surgery in the pregnant patient. Edwards RK, Ripley DL... more 1. Curr Probl Surg. 2001 Apr;38(4):213-90. Surgery in the pregnant patient. Edwards RK, Ripley DL, Davis JD, Bennett BB, Simms-Cendan JS, Cendan JC, Stone IK. Division of Maternal Fetal Medicine, Department of Obstetrics ...
Studies in health technology and informatics, 2008
Modeling soft tissue for surgery simulation is a challenging task due to the complex way that the... more Modeling soft tissue for surgery simulation is a challenging task due to the complex way that the tissue can deform and interact with virtual surgical tools manipulated by user. One soft tissue that is ubiquitous but often not modeled, is fatty tissue. Here we present a novel fatty tissue model based on the mass-spring system on the Graphics Processing Unit (GPU) as part of our Toolkit for Illustration of Procedures in Surgery (TIPS). The user can interact with the fatty tissue in real time via a handheld haptic stylus that represents a virtual surgical tool in TIPS environment. The currently available interactions are palpation, grasp, and cut.
Studies in health technology and informatics, 2012
We introduce the notion of Shader Lamps Virtual Patients (SLVP) - the combination of projector-ba... more We introduce the notion of Shader Lamps Virtual Patients (SLVP) - the combination of projector-based Shader Lamps Avatars and interactive virtual humans. This paradigm uses Shader Lamps Avatars technology to give a 3D physical presence to conversational virtual humans, improving their social interactivity and enabling them to share the physical space with the user. The paradigm scales naturally to multiple viewers, allowing for scenarios where an instructor and multiple students are involved in the training. We have developed a physical-virtual patient for medical students to conduct ophthalmic exams, in an interactive training experience. In this experience, the trainee practices multiple skills simultaneously, including using a surrogate optical instrument in front of a physical head, conversing with the patient about his fears, observing realistic head motion, and practicing patient safety. Here we present a prototype system and results from a preliminary formative evaluation of ...
The use of virtual characters in a variety of research areas is widespread. One such area is heal... more The use of virtual characters in a variety of research areas is widespread. One such area is healthcare. The study presented in this paper leveraged virtual patients to examine whether virtual patients are more likely to be correctly diagnosed due to gender and skin tone. Medical students at the University of Florida College of Medicine interacted with six virtual patients across two sessions. The six virtual patients comprised various combinations of gender and skin tone. Each virtual patient presented with a different cranial nerve injury. The results indicate a significant difference in correct diagnosis according to patient gender for one of the cases. In that case, female patients were correctly diagnosed more frequently than their male counterpart. The description of that case required that the virtual patient present with a visible bruise on the forehead. We hypothesize the results obtained could be due to a transfer of a real world gender bias.
Metastatic Lobular Breast Cancer Presenting with Malignant Ascites: Case Report and Review of Literature
The Breast Journal, 2003
We review the case of an elderly woman with invasive lobular breast cancer presenting as malignan... more We review the case of an elderly woman with invasive lobular breast cancer presenting as malignant ascites. This unusual presentation is discussed, as well as the options for treatment. Most invasive lobular breast cancers are hormone receptor positive and the roles of hormonal and chemotherapy are reviewed.
A primer on standards setting as it applies to surgical education and credentialing
Surgical Endoscopy, 2013
Surgical technological advances in the past three decades have led to dramatic reductions in the ... more Surgical technological advances in the past three decades have led to dramatic reductions in the morbidity associated with abdominal procedures and permanently altered the surgical practice landscape. Significant changes continue apace including surgical robotics, natural orifice-based surgery, and single-incision approaches. These disruptive technologies have on occasion been injurious to patients, and high-stakes assessment before adoption of new technologies would be reasonable. We reviewed the drivers for well-established psychometric techniques available for the standards-setting process. We present a series of examples that are relevant in the surgical domain including standards setting for knowledge and skills assessments. Defensible standards for knowledge and procedural skills will likely become part of surgical clinical practice. Understanding the methodology for determining standards should position the surgical community to assist in the process and lead within their clinical settings as standards are considered that may affect patient safety and physician credentialing.
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Papers by Juan Cendan