Referral Letter

A typical referral letter arrives in my tray:

A 55-year-old diabetic female noticed pain and discoloration of the right foot for several days.

 

Immediate admission was arranged for this patient:

A junior resident presents the case. She has clerked the patient and filled all the necessary forms and ticked all the necessary boxes. Everything is dated and signed appropriately. Her ankle brachial index is 0.7 on the right and 1.1 on the left. The patient falls in a Rutherford Class IV. With such thorough documentation, we were ready to pay the patient a visit and consent her for the planned peripheral angiogram and revascularization. This resident rounds with me every day and has clearly understood the process of consenting: procedural steps and complications included. I told my resident that I appreciate her energy and proactivity. I was so proud of her and thought “Hmm very little left for me to teach this young lady”. So, we walked over to the patient’s room to meet her and her family.

 

We enter the patient’s room:

My resident starts introducing the patient to me and recapping her history. In the meantime, I look at my patient from a distance. I immediately notice the anxious look. Perhaps she’s nervous about her foot and a possible amputation. I also notice how thin she is. Something doesn’t add up.  Diabetes is on the rise worldwide. Most of our poorly controlled diabetics who present with peripheral vascular disease have other end organ damage like some nephropathy or retinopathy. Most are overweight. She has none. I flip the chart in my hand and notice that her HbA1C is 7%. I ask about her weight loss. “It’s all very recent”, she says. I ask about other constitutional signs and she states there are none. She also has had no history of claudication. This doesn’t sound like long standing atherosclerosis. I approached her to examine her. I held her hand for the first time to feel her pulse. Oh, the lost art of a physical examination..Why examine her when her peripheral vasculature will be defined by a CTA and all the boxes in the chart are ticked?  The answer was right there: she was in atrial fibrillation. I glance at her EKG and sure enough she is in atrial fibrillation. Her hands told me more. She was sweating and had a tremor. I knew at this point what I needed to teach my resident. Medicine is so vast and so integrated. We cannot presume cardiovascular diseases and endocrine disorders are not interrelated. After all, this patient needed an endocrinologist.

 

Later that day she was taken to the cathlab:

Her TSH was high. Her transesophageal echocardiogram confirmed a left atrial thrombus. We discussed acute limb ischemia with the endocrinologist. We administered B blockers and obtained a consent for the procedure. Her angiogram revealed a thrombus at the right tibioperoneal trunk. Instead of whipping out the QuickCross microcatheter and GlideAdvantage wire, I performed manual aspiration of the thrombus. Fortunately, flow was restored almost immediately. The Society for Vascular Surgery and the North American Chapter of the International Society of Cardiovascular Surgery created a classification that ranged from non-threatened extremity, threatened extremity to finally ischemia with no possible salvage in 2002. Timely intervention is warranted in salvageable cases. Fogarty established surgical thromboembolectomy as the standard of care in the 1960s. Dotter introduced thrombolysis in the 1970s which evolved to current day catheter directed thrombolysis and aspiration. Both surgical and catheter directed thrombectomy have been studied. Theodoridis et al published a review article that indicated the technical success rate of endovascular techniques reaches 79.3%. A second procedure was required in 77.8% of those enrolled. The overall complication rate was 28.7%. Novel techniques that combine catheter directed low dose thrombolysis with and without mechanical thrombectomy have also been evaluated and found to be largely comparable.1-3 Procedural questions related to my patient were confined to the following:

  1. Use of a distal protection device: Trials have demonstrated a wide variation in the rate of distal embolization. This wide range is explained by the different lesion types, lengths, treatment modalities. The highest rate is in those with TASC C and D lesions, acute and subacute presentations, and with the use of atherectomy devices.4-10 However, major adverse events and amputations rates have not been significantly reduced with the use of distal protection devices.
  2. Use of an infusion catheter is usually reserved for cases where adequate flow and removal of thrombus is inadequate.

 

Upon returning to her room, there was more to discuss:

Her thyrotoxicosis was under investigation and control. Her atrial fibrillation needed to be addressed at this point. She needed rate control until she becomes euthyroid. With a thrombus in her left atrium and embolization to her lower extremity, she needed anticoagulation. The choice of an agent is another lesson for another day.

The resident and I walked out of her room with a sense of satisfaction. Both of us learned something that day. A patient is more than a referral letter..much more.

 

REFERENCES:

  1. Shrikhande GV, Khan SZ, Hussain HG, et al. Lesion types and device characteristics that predict distal embolization during percutaneous lower extremity interventions. J Vasc Surg2011;53(2):347–52.
  2. Shammas NW, Shammas GA, Dippel EJ, et al. Predictors of distal embolization in peripheral percutaneous interventions: a report from a large peripheral vascular registry. J Invasive Cardiol2009;21(12):628–31.
  3. Mendes BC, Oderich GS, Fleming MD, et al. Clinical significance of embolic events in patients undergoing endovascular femoropopliteal interventions with or without embolic protection devices. J Vasc Surg2014;59(2):359–67.e1.PMCID: PMC4492297
  4. Shammas NW, Coiner D, Shammas GA, et al. Distal embolic event protection using excimer laser ablation in peripheral vascular interventions: results of the DEEP EMBOLI registry. J Endovasc Ther2009;16(2):197–202.
  5. Karnabatidis D, Katsanos K, Kagadis GC, et al. Distal embolism during percutaneous revascularization of infra-aortic arterial occlusive disease: an underestimated phenomenon. J Endovasc Ther2006;13(3):269–80.
  6. Shammas NW, Dippel EJ, Coiner D, et al. Preventing lower extremity distal embolization using embolic filter protection: results of the PROTECT registry. J Endovasc Ther 2008;15(3):270–6.
  1. Rheolytic Pharmacomechanical Thrombectomy for the Management of Acute Limb Ischemia: Results From the PEARL Registry. Leung DA, et al. J Endovasc Ther. 2015
  2. Acute on chronic limb ischemia: From surgical embolectomy and thrombolysis to endovascular options. de Donato G, et al. Semin Vasc Surg. 2018
  3. Thrombolysis in Acute Lower Limb Ischemia: Review of the Current Literature. Theodoridis PG, et al. Ann Vasc Surg. 2018.
  4. Comparison of Low-Dose Catheter-Directed Thrombolysis with and without Pharmacomechanical Thrombectomy for Acute Lower Extremity Ischemia. Gandhi SS, et al. Ann Vasc Surg. 2018.

 

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