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Injuries to the portal triad
LETTERS TO THE EDITOR
tension with massive edema of the arm. Due to these experiences, we have started-using subclavian dialysis catheters for as short a time as possible, perhaps 5 to 7 days. We do not use them in outpatients because we believe that the added mobility of an outpatient will increase the incidence of scarring and inflammation of the subclavian vein. Another strategy that we have devised is to evaluate those patients requiring emergency dialysis in order to find a useable cephalic vein. If the patient has one, we place a Gortex graft in the contralateral arm; then, at some point in the future, we place a Brescio-Cimino fistula using the good cephalic vein. Consequently, wheaa the Gortex graft fails, the patient will already have a matured Brescio-Cimino fistula. I agree that, in most patients who have continued complications and thrombosis associated with arterialvenous fistulas, the use of a Permacath is the preferred path to take. However, I believe that this should be the last alternative selected because of the aforementioned complications. Stephen L. Hill, MD, FACS Roanoke, VA 1. Hill SL, Berry RE. Subclavian vein thrombosis: a continuing challenge. Surgery 1990; 108: 1-9. 2. Hill SL, Martin D, Evans P. Massivevenous thrombosis of the extremities. Am J Surg 1989; 158:131-5.
INJURIES TO T H E PORTAL TRIAD
To the E d i t o r : The cover of the May 1991 issue of The American Journal o f Surgery, in which the papers of the North Pacific Surgical Association were presented, listed as the lead article a paper on injuries to the portal triad [1]. It was my understanding in medical school that the portal triad was a microscopic structure within the liver that consists of the portal vein, the hepatic artery or arteriole, and the bile duct. The structures discussed in the article are the extrahepatic structures in the porta hepatis and, I think, incorrectly named structures of the 318
portal triad. It would seem appropriate to correct this anatomic misunderstanding, which Drs. Dawson, Johansen, and Jurkovich have discussed in this article and which apparently was passed over both at the North Pacific Surgical Association meeting and by the editorial board of The American Journal o f Surgery. C. John Snyder, MD Santa Cruz, CA 1, DawsonDL,Johansen KH, JurkovichGJ. Injuries to the portal triad. Am J Surg 1991; 161: 545-51.
In Response:
We thank Dr. Snyder for his interest in our article. Although we agree that the term "portal triad" has classically been used by histologists and pathologists to describe the intrahepatic ductal radicles and their associated portal venous and hepatic arteriolar branches, we contend that the term is also appropriately applied to define the bile duct, portal vein, and hepatic artery where they course together in the hepatoduodenal ligament and portal hepatis. By referring to "injuries to the portal triad," we referred specifically t o injuries of these three structures, rather than to injuries in their general anatomic region (the porta hepatis) or the fold of peritoneum in which they are enclosed (the ,hepatoduodenal ligament). 9 Stedman's Medical Dictionary defines "triad" as "a collection of three things having something in common" [1]. The extrahepatic bile duct, portal vein, and hepatic artery have several things in common: their location and anatomic relationships, their infrequent occurrence of injury, and the surgical challenge of injury to one or more of these structures, which is accompanied by a significant risk of complications or death. These structures also share a risk of injury when exposed to wounding mechanisms (especially penetrating trauma). In 3 of 21 (14%) patients we reported, trauma resulted in an injury to all 3 of the portal triad structures. In two previous reports that examined these injuries as a group, combined injuries were found in 24% [2,3]. This supports the im-
portance of considering the structures of this triad as a unit. The use of the term "portal triad" to collectively describe the extrahepatic duct, vein, and artery is neither unique nor original to us. A search of the National Library of Medicine's M E D L I N E database finds similar use of this term by surgeons and surgical researchers in the contemporary scientific literature of the United States, Europe, China, and Japan. In several articles, the term "portal triad" was used to emphasize that the extrahepatic bile duct, portal vein, and hepatic artery were being considered together, as a functional or anatomic unit. As an example, the Pringle maneuver can be appropriately referred to as "portal triad clamping" [4-7]. Intentional emphasis of the importance of the anatomic relationships of the region of the porta hepatis, not an anatomic misunderstanding, prompted us to use the term "portal triad" as we did. David L. Dawson, MD Kaj H. Johansen, MD, PhD Gregory J. Jurkovich, MD University of Washington Medical Center Seattle, WA 1. Stedman's Medical Dictionary. 23rd ed. Baltimol'e, MD: Waverly Press Inc., 1976: 1475. 2. Busuttil RW, Kitahama A, Cerise E, McFadden M, Lo R, Longmire WP. Management of blunt and penetrating injuries to the porta hepatis. Ann Surg 1980; 191: 641-8. 3. Sheldon GF, Lim RC, Yee ES, Petersen SR. Management of injuries to the porta hepatis. Ann Surg 1985; 202: 539-45. 4. Elias D, Desruennes E, Lasser P. Prolonged intermittent clamping of the portal triad during hepatectomy. Br J Surg 1991; 78: 42-4. 5. Delva E, Camus Y, Nordlinger B, et al. Vascular occlusions for liver resections. Operative management and tolerance to hepatic ischemia: 142 cases. Ann Surg 1989; 209: 211-8. 6. Yamaoka Y, Ozawa K, Shimahara Y, et al. A simple and direct approach to the portal triad structures for a left lobectomyor a left lateral segmentectomy. Surg Gynecol Obstet 1988; 166: 78-80. 7. Pachter HL, Spencer FC, Hofstetter SR, Liang HC, Coppa GF. The management of juxtahepatic venous injuries without an atriocaval shunt: preliminary clinical observations. Surgery 1986; 99: 569-75.
THE AMERICAN JOURNALOF SURGERY VOLUME 166 SEPTEMBER 1993
tension with massive edema of the arm. Due to these experiences, we have started-using subclavian dialysis catheters for as short a time as possible, perhaps 5 to 7 days. We do not use them in outpatients because we believe that the added mobility of an outpatient will increase the incidence of scarring and inflammation of the subclavian vein. Another strategy that we have devised is to evaluate those patients requiring emergency dialysis in order to find a useable cephalic vein. If the patient has one, we place a Gortex graft in the contralateral arm; then, at some point in the future, we place a Brescio-Cimino fistula using the good cephalic vein. Consequently, wheaa the Gortex graft fails, the patient will already have a matured Brescio-Cimino fistula. I agree that, in most patients who have continued complications and thrombosis associated with arterialvenous fistulas, the use of a Permacath is the preferred path to take. However, I believe that this should be the last alternative selected because of the aforementioned complications. Stephen L. Hill, MD, FACS Roanoke, VA 1. Hill SL, Berry RE. Subclavian vein thrombosis: a continuing challenge. Surgery 1990; 108: 1-9. 2. Hill SL, Martin D, Evans P. Massivevenous thrombosis of the extremities. Am J Surg 1989; 158:131-5.
INJURIES TO T H E PORTAL TRIAD
To the E d i t o r : The cover of the May 1991 issue of The American Journal o f Surgery, in which the papers of the North Pacific Surgical Association were presented, listed as the lead article a paper on injuries to the portal triad [1]. It was my understanding in medical school that the portal triad was a microscopic structure within the liver that consists of the portal vein, the hepatic artery or arteriole, and the bile duct. The structures discussed in the article are the extrahepatic structures in the porta hepatis and, I think, incorrectly named structures of the 318
portal triad. It would seem appropriate to correct this anatomic misunderstanding, which Drs. Dawson, Johansen, and Jurkovich have discussed in this article and which apparently was passed over both at the North Pacific Surgical Association meeting and by the editorial board of The American Journal o f Surgery. C. John Snyder, MD Santa Cruz, CA 1, DawsonDL,Johansen KH, JurkovichGJ. Injuries to the portal triad. Am J Surg 1991; 161: 545-51.
In Response:
We thank Dr. Snyder for his interest in our article. Although we agree that the term "portal triad" has classically been used by histologists and pathologists to describe the intrahepatic ductal radicles and their associated portal venous and hepatic arteriolar branches, we contend that the term is also appropriately applied to define the bile duct, portal vein, and hepatic artery where they course together in the hepatoduodenal ligament and portal hepatis. By referring to "injuries to the portal triad," we referred specifically t o injuries of these three structures, rather than to injuries in their general anatomic region (the porta hepatis) or the fold of peritoneum in which they are enclosed (the ,hepatoduodenal ligament). 9 Stedman's Medical Dictionary defines "triad" as "a collection of three things having something in common" [1]. The extrahepatic bile duct, portal vein, and hepatic artery have several things in common: their location and anatomic relationships, their infrequent occurrence of injury, and the surgical challenge of injury to one or more of these structures, which is accompanied by a significant risk of complications or death. These structures also share a risk of injury when exposed to wounding mechanisms (especially penetrating trauma). In 3 of 21 (14%) patients we reported, trauma resulted in an injury to all 3 of the portal triad structures. In two previous reports that examined these injuries as a group, combined injuries were found in 24% [2,3]. This supports the im-
portance of considering the structures of this triad as a unit. The use of the term "portal triad" to collectively describe the extrahepatic duct, vein, and artery is neither unique nor original to us. A search of the National Library of Medicine's M E D L I N E database finds similar use of this term by surgeons and surgical researchers in the contemporary scientific literature of the United States, Europe, China, and Japan. In several articles, the term "portal triad" was used to emphasize that the extrahepatic bile duct, portal vein, and hepatic artery were being considered together, as a functional or anatomic unit. As an example, the Pringle maneuver can be appropriately referred to as "portal triad clamping" [4-7]. Intentional emphasis of the importance of the anatomic relationships of the region of the porta hepatis, not an anatomic misunderstanding, prompted us to use the term "portal triad" as we did. David L. Dawson, MD Kaj H. Johansen, MD, PhD Gregory J. Jurkovich, MD University of Washington Medical Center Seattle, WA 1. Stedman's Medical Dictionary. 23rd ed. Baltimol'e, MD: Waverly Press Inc., 1976: 1475. 2. Busuttil RW, Kitahama A, Cerise E, McFadden M, Lo R, Longmire WP. Management of blunt and penetrating injuries to the porta hepatis. Ann Surg 1980; 191: 641-8. 3. Sheldon GF, Lim RC, Yee ES, Petersen SR. Management of injuries to the porta hepatis. Ann Surg 1985; 202: 539-45. 4. Elias D, Desruennes E, Lasser P. Prolonged intermittent clamping of the portal triad during hepatectomy. Br J Surg 1991; 78: 42-4. 5. Delva E, Camus Y, Nordlinger B, et al. Vascular occlusions for liver resections. Operative management and tolerance to hepatic ischemia: 142 cases. Ann Surg 1989; 209: 211-8. 6. Yamaoka Y, Ozawa K, Shimahara Y, et al. A simple and direct approach to the portal triad structures for a left lobectomyor a left lateral segmentectomy. Surg Gynecol Obstet 1988; 166: 78-80. 7. Pachter HL, Spencer FC, Hofstetter SR, Liang HC, Coppa GF. The management of juxtahepatic venous injuries without an atriocaval shunt: preliminary clinical observations. Surgery 1986; 99: 569-75.
THE AMERICAN JOURNALOF SURGERY VOLUME 166 SEPTEMBER 1993